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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Brosol on November 07, 2010, 11:35:38 PM
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My A3000 has a history of over-heating related problems which causes system instability, random crashes & lock ups during large file transfers & booting up.
The problems seem to be caused by overheating of the chips on the Zorro Slot side of the case.
I tried to fix this by:
- Installing 400W PSU with high CFM fan
- putting heatsinks on every heat producing chip (CIA, Amber, SDMAC, SBuster, 68030 CPU, chips next CHIP RAM area in front of the LED, U714 gets very hot)
- installing fans, PSU fan, exhaust slot fan
- replaced GALS U202, U203, U714
Despite all this the A3000 still has SCSI R/W errors & lock ups problems. I placed a temp probe on U714 which gets very hot. Problems start to show up when the temp reaches 34plus deg C. Its a problem during the summer when the ambient temp is too high for fans to help or when running with the case cover on. I not sure if U714 is the culprit since it was replaced new or is the indicator of other problems
Now my Deneb is acting weird despite U714 temp probe showing a cool 22degC. Its showing R/W error problems booting and copying files between Deneb USB drives, file transfers between Deneb USB and A3000S SCSI drives.
I removed all cards exept the Deneb. Swaping Deneb in ZorroIII slots seems to help temporarily but the intermittent stability problems persist.
Could bad aging caps be the cause? What are the signs of bad caps? I wonder if A3000D motherboard caps replacement (offered by Cosmos) would help fix the instability problems?
(http://i687.photobucket.com/albums/vv232/Zardoz1377c/A3000_2840122742006.jpg)
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Hi,
A few dozen things come to mind on this: first start with the psu, check the 5v rail when your are loading it heavy,monitor it with a meter..it should maintain about 4.92v or better(some say 4.80's are ok,but my experience says otherwise). there are many many bad psu's out there,and 400W doesn't mean anything, its more important what the rails can handle individually.I've seen 400W pc power supplies that should be rated 250w..
Cheap/bad caps in the psu can also put out dirty power and cause lotsa troubles.Check the motherboard connector and the pigtail from the psu, notorious for having a bad 5v connection.checking power before the connector on the psu and somewhere near the power connector on the motherboard should show close voltage.
Assuming thats good, reseating chips-pushing on them is useless, pull them and reseat them(i doubt this is the trouble though) but we have 20 year old contacts here!Use a proper plcc puller, on those old sockets!. The pals and stuff on the side of the board you mention run quite hot normally,but usually run along happily that way.
I don't think heat is your problem but may aggravate the situation if you have a borederline component. Bad ram may very well be the trouble,and hot ram chips can be a sign of bad ram.This could cause most of the problems you mention and have effects system wide.
The wrong mask/max transfer values could also cause some of the troubles(may be a combination of things)But you said this combo ran ok before?.
Improper termination(check the diodes are the right way around,some 3000's had them soldered in wrong giving no term power to the scsi).Do you have the latest WD -08 scsi chip or the amd version?
Do you have a battery installed and looked at the battmem?Maybe a scsi setting is off there but this is doubtfull?
It could be your buster chip is flakey,you don't mention what revision??
Usually when you replace the PAL chips with GAL's they run alot cooler.Are you sure the replacements are GALS? Are the GAL replacements at least as fast or faster than the originals?maybe a bad replacement chip?
Capacitors could be going bad,especially after nearly 20 yrs, but i'm leaning toward bad ram,flakey psu or a flakey buster? Btw,what rev buster do you run?
This probabaly doesn't help much,being able to substitute parts with known good helps.
If you find the trouble,please report back on it.
Mike
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Hi,
A few dozen things come to mind on this: first start with the psu, check the 5v rail when your are loading it heavy,monitor it with a meter..it should maintain about 4.92v or better(some say 4.80's are ok,but my experience says otherwise).
>>>> 5v Rail: 5.03V during large file R/W
there are many many bad psu's out there,and 400W doesn't mean anything, its more important what the rails can handle individually.I've seen 400W pc power supplies that should be rated 250w..
Cheap/bad caps in the psu can also put out dirty power and cause lotsa troubles.Check the motherboard connector and the pigtail from the psu, notorious for having a bad 5v connection.checking power before the connector on the psu and somewhere near the power connector on the motherboard should show close voltage.
>>>> seems to be OK
Assuming thats good, reseating chips-pushing on them is useless, pull them and reseat them(i doubt this is the trouble though) but we have 20 year old contacts here!Use a proper plcc puller, on those old sockets!.
>>>> Have not done this yet....need a plcc puller to prevent possible damage to chips and sockets.
The pals and stuff on the side of the board you mention run quite hot normally,but usually run along happily that way.
I don't think heat is your problem but may aggravate the situation if you have a borederline component.
>>>> I think so as well, as the unknown problem becomes worse its becoming more heat sensitive
Bad ram may very well be the trouble,and hot ram chips can be a sign of bad ram.This could cause most of the problems you mention and have effects system wide.
>>>> The chip ram is not hot, I just put heatsinks there as a precaution since it right next to the hot chips. Ram tests via SCRAMmer 37.3 were OK.
The wrong mask/max transfer values could also cause some of the troubles(may be a combination of things)But you said this combo ran ok before?.
Improper termination(check the diodes are the right way around,some 3000's had them soldered in wrong giving no term power to the scsi).Do you have the latest WD -08 scsi chip or the amd version?
>>>> Using -08 WD SCSI chip, mask/max transfers & termination are OK. Problems pop up when the temp probe on U714 heatsink indicates 34-37+ Deg C temps. I have especially have problems running it during the summer months
Do you have a battery installed and looked at the battmem?Maybe a scsi setting is off there but this is doubtfull?
>>>> Battery was replaced, no acid damage, SCSI settings OK.
It could be your buster chip is flakey,you don't mention what revision??
Usually when you replace the PAL chips with GAL's they run alot cooler.Are you sure the replacements are GALS? Are the GAL replacements at least as fast or faster than the originals?maybe a bad replacement chip?
>>>> I got GAL U202, U203, U714 replacements from....Anthony Hoffman so I'm sure its ok.
Capacitors could be going bad,especially after nearly 20 yrs, but i'm leaning toward bad ram,flakey psu or a flakey buster? Btw,what rev buster do you run?
>>>> Using Rev-09 SBuster with SB-09 flash Deneb support. My recent Deneb instability problems don't seem to be related to overheating....U714 temp probe showed a cool 20deg C during Deneb problems.
>>>>Things to try: reseating the chips, replace SB-09 with SB-11 which is supposed to be more stable with Deneb, try another PSU, Caps replacement (what would be symptoms of aging caps?)
This probabaly doesn't help much,being able to substitute parts with known good helps.
If you find the trouble,please report back on it.
>>>> Its very helpful....much appreciated:lol:
Mike
A
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My bet is on the caps, esp. if the machine has high running hours (=in use frequently) and developed this problem little by little. They can cause lots of noise on the voltage lines.
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Yes that exactly how the intermittent problems are cropping up, little by little becoming more unstable as its being used.
I got back to playing with my A3000 for over year now after 10yrs of storage. Its on frequently and slowly upgraded:
A3000 25MHZ 2mb Chip, 16mb Fast
WDC 00-08 SCSI Controller
DB25 Ext SCSI Terminator
Super Buster 9
KS 3.1 Roms
Lithium Clock Battery Holder
CyberVision 64 4MB
Indivsion ECS
Deneb
FastATA 4000 MK-V==>IDE-CF Reader
A3000 SCSI==>SCSI-IDE Bridge==>IDE-CF Reader
Drive platform mod to allow 68060 HS/Fan clearance
Cyberstorm MKII, 128MB
MC68060RC50 CPU 71E41J mask
66.66 mhz Crystal Oscillator
PS/2 Usb Mouse Adapter
Modded A3000 PSU (Original Case)
- 400W Duro ATX PSU PCB
- 80mm ThermalTake A128025BUT Fan
- A3000 ATX PSU Cable
Heatsinks: DMAC, 68030, 68060
Heatsinks for heat producing IC chips
New GAL U202, U203, U714 replacement
Lyra 1 PC Keyboard adapter
MAS-Player Pro 2
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Usually when you replace the PAL chips with GAL's they run alot cooler.Are you sure the replacements are GALS? Are the GAL replacements at least as fast or faster than the originals?maybe a bad replacement chip?
>>>> I got GAL U202, U203, U714 replacements from....Anthony Hoffman so I'm sure its ok.
Yes, those parts are modern equivalents to the original programmable logic. They can run faster, draw less current and as a result will dissipate less heat.
Reseating all the socketed devices is a good suggestion, plus it doesn't cost anything. Be careful not to bend legs when re-inserting, etc.
Personally I wouldn't expect it to be a capacitor related issue. While the electrolytics do reduce in capacity with age and heat, I wouldn't expect such a capacity loss to cause that much grief. Maybe if the capacity were to reduce more than 50%, although that kind of reduction is unlikely in all of the electrolytics in only 20 years or so.
All of the high frequency decoupling is done using ceramic and monolithic capacitors, the small blue/yellow ones by each IC. These devices are very stable with heat and age and would have degraded very insignificantly.
Another suggestion is to remove the case cover from the A3000 to help test the heating theory. Although this stops the fan drawn air circulation, it does promote convectional air flow. One of my A3000s tends to start having heat related problems similar to what you describe after a few hours running. Without the case cover on it seems quite reliable though. Does have a lot of crap installed in there, Cyberstorm mk2, Picasso IV, etc, etc. Not surprising that air circulation is poor and heat buildup is an issue. Never did solve the problem, the A3000 only gets infrequent use as it's the backup for the main computer (A4000T).
Last suggestion is send it down here to Antarctica :) I've only seen it down to -30C so far, but it'll get colder during winter. If that doesn't keep the A3000 cool then nothing will!
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Ok just noticed another problem...the video output from the A3000 flickerfixer is very jittery while the Indivision ECS video is rock stable and clear.
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Yes, those parts are modern equivalents to the original programmable logic. They can run faster, draw less current and as a result will dissipate less heat.
Reseating all the socketed devices is a good suggestion, plus it doesn't cost anything. Be careful not to bend legs when re-inserting, etc.
Ok like you say its free...I will try it
Another suggestion is to remove the case cover from the A3000 to help test the heating theory.
I'm doing this test now running without zorro cards, doing boot and R/W file tests on CF cards. I will post the results with pics.
Although this stops the fan drawn air circulation, it does promote convectional air flow. One of my A3000s tends to start having heat related problems similar to what you describe after a few hours running. Without the case cover on it seems quite reliable though. Does have a lot of crap installed in there, Cyberstorm mk2, Picasso IV, etc, etc. Not surprising that air circulation is poor and heat buildup is an issue. Never did solve the problem, the A3000 only gets infrequent use as it's the backup for the main computer (A4000T).
Wow if not even you found a solution for the poor air circulation and heat build up....then there's no hope? :eek:
I found this link from a A3000 user with related heat & poor circulation problems. Its seems to work for him but I'm not certain I wan't to hack up and alter the look of the A3000 case to such extremes.
http://www.a1k.org/forum/showthread.php?t=16295
http://www.a1k.org/forum/attachment.php?attachmentid=17354&d=1247933590
http://www.a1k.org/forum/attachment.php?attachmentid=17353&d=1247933572
http://www.a1k.org/forum/attachment.php?attachmentid=17355&d=1247933609
I was thinking about a stealthier version of this mod by cutting a hole to fit a skinny high speed 70mmx15mm 46CFM fan next to the LEDs behind the bezel. I don't want to drill holes or drastically change the look of the bezel. I hope the combo of the front intake and rear slot exhaust fan will provide enough airflow to dump out the heat & counter the heat build up with Zorro cards installed. It probally won't help during hot summer ambient temperatures.
Last suggestion is send it down here to Antarctica :) I've only seen it down to -30C so far, but it'll get colder during winter. If that doesn't keep the A3000 cool then nothing will!
Or I get a AC unit and run it perpetually but I don't want to pay the power bills. I think a running a long dryer hose to pipe in that cool Antartic air is the best solution. :roflmao:
Quick Update: Running with case open, no zorro cards, no fans, just heatsinks & convection cooling:
U714 Temp Probe: 42.2 deg C, 5V Rail: 5.06V
System Behavior: unstable, checksum disk block errors, lock ups during booting. Tried different known to work CF cards but same results. :(
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This totally sounds like a bad config in your SCSI transfers. Did you check the battery mem as Mechy suggested? Here's a utility to get you into it:
http://aminet.net/package/util/sys/SetBatt1_0
...MaxTransfer values next in HDToolBox and then your CF card adapter jumper settings are suspect too.
BTW: Are you strictly using a SCSI<>IDE<>CF Card adapter (or SCSI<>CF adapter)? Does the computer behave when you use a good old fashioned SCSI hard drive?
I've had mixed results using CF Cards with Amiga's. The cheapo adapters you find on ePay and elsewhere are not always the most compatible and neither are several CF card brands. After all the monkeying around I've done with various HD alternatives, I still find hard drives to be the best, most reliable solutions inside Amiga's.
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This totally sounds like a bad config in your SCSI transfers. Did you check the battery mem as Mechy suggested? Here's a utility to get you into it:
http://aminet.net/package/util/sys/SetBatt1_0
A3000 SCSI config:
SCSI TimeOut Short: 128ms
LUNS Only 0
Fast Sychronous On
SCSI Queues Off
...MaxTransfer values next in HDToolBox and then your CF card adapter jumper settings are suspect too.
BTW: Are you strictly using a SCSI<>IDE<>CF Card adapter (or SCSI<>CF adapter)? Does the computer behave when you use a good old fashioned SCSI hard drive?
I tried FFS, SFS using default values. What do you suggest for CF cards?
I am using A3000SCSI<>SCSItoIDE Bridge<>IDEtoCF adapter<>CF card. I don't have any SCSI HD anymore.
I've had mixed results using CF Cards with Amiga's. The cheapo adapters you find on ePay and elsewhere are not always the most compatible and neither are several CF card brands. After all the monkeying around I've done with various HD alternatives, I still find hard drives to be the best, most reliable solutions inside Amiga's.
Just until recently did the problems started to crop up more and more. The Deneb related problems are new.
Test Results #2
Temp Probe: 22.5C, case open, CPU Fan blowing over heatsink, cool intake air from outside.
Behavior: seems stable, successful booting from CF and large file transfers between CFs OK without errors. 1 CF card become corrupted from the Test#1 and had to be reformatted.
Test Results #3
Temp Probe: 22.5C, case open, CPU Fan blowing, Deneb Installed in Zorro slot 3 from the top
Behavior: successful booting from CF, Fat32 USB drive recognized & mounted. Tried to extract a large LHA from USB to CF...failed causing a reboot.
Tried Deneb in Zorro slot 1 from top....failed to mount Fat32 drive. Tried FFS, SFS USB drives....mounts but large file transfers working intermittently. Again this is a new Deneb problem which happening despite cool temperatures.
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I'm using 4GB-Timu Premium UDMA CF, 8GB-Pixelflash 233x-Pro CF, 4GB-Diesel & 8GB-X-Mini Patriot USB drives.
Filesystems: FFS, SFS, Fat32 for PC<>Amiga
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Ok just noticed another problem...the video output from the A3000 flickerfixer is very jittery while the Indivision ECS video is rock stable and clear.
Try adjusting the flicker fixer potentiometer and see if it clears up,these variable resistors do degrade over time.
mike
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I'm using 4GB-Timu Premium UDMA CF, 8GB-Pixelflash 233x-Pro CF, 4GB-Diesel & 8GB-X-Mini Patriot USB drives.
Filesystems: FFS, SFS, Fat32 for PC<>Amiga
I personally run 2-32GB kingston pro cards off my UWscsi on the cyberstorm ppc with Acard adapters to cf adapters wired for proper DMA. its been working 100% for 2 years+ now.
I only run SFS 1.279 on my stuff. read the full archive docs included 1.277.. it suggests max transfers for scsi and ide,and if the full dma scsi values dont work,drop down as suggested.
Stay away from all the off brand cf's they are nothing but trouble.kingston elite pro(had trouble with 4gb regular kingstons),sandisk(dont buy off ebay unless u can verify they arent bootleg),transcend 2,4gb cards works well in 80x,133x,etc).
You cf adapter can make or break you. you might also try dropping synchronous on the scsi but i doubt it will be the cause..
still think you have bad ram somewhere ;)
Now you know why i have 2 of every amiga here ;) always handy to swap parts with known good.
just for the record ,i ran a A3000 rev9.2 with piv,ariadneII,A3640,vlab y/c,2hd floppies,2 scsi hds internal,external scsi cdrw for many years with stock psu and stock case with only a added 3" fan blowing on the zorro side cards and it ran 100% stable for over 5 yrs,i never heatsinked the pal's but they did run blistering hot....putting heatsinks on these is probabaly the best thing. we see 105F regularly here in texas summers. We do have a/c tho :)
fast forward 10+ years and you have older caps,and tarnished sockets :) keep at it,i think you will find the trouble.
mike
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Yes I'm using a R-IDSC-E/R SCSI-IDE bridge and Ebay CF adapter & Ebay CF cards
http://cgi.ebay.com/CF-Card-3-5-40-PIN-IDE-SSD-HDD-Adapter-Back-Panel-/260624996786?pt=LH_DefaultDomain_0&hash=item3cae75d9b2
How do I know & choose better CF adapters?
USB drives were purchased local NCIX:
http://ncix.com/products/?sku=39651&vpn=OCZUSBDSL4G&manufacture=OCZ%20Technology
http://ncix.com/products/index.php?sku=28946&vpn=PSF8GMUSB&manufacture=Patriot
If the chips reseating doesn't work I will swap out the chip & zip and MKII ram. ;)
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I personally run 2-32GB kingston pro cards off my UWscsi on the cyberstorm ppc with Acard adapters to cf adapters wired for proper DMA. its been working 100% for 2 years+ now.
I only run SFS 1.279 on my stuff. read the full archive docs included 1.277.. it suggests max transfers for scsi and ide,and if the full dma scsi values dont work,drop down as suggested.
I'm not having much luck playing with SFS 1.279. I set things up via WinUAE and test them on the A3000. I tried suggested max transfers and mask values but still getting boot problems:
Mask:0xFFFFFFFF
Max Transfer: 0x7FFFFFFF, 0x1FFFE, 0xFFFE
What SFS values should I try for A3000 SCSI, SCSI-IDE bridge & CF combo?
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Wow if not even you found a solution for the poor air circulation and heat build up....then there's no hope?
Actually I never really looked for a solution. Suspect it would probably be better with decent air circulation, etc, but that involves cutting holes and mounting fans. There's probably other solutions, but I lacked time to try things. Plus I know the Cyberstorm mk2 is running a bit hotter than it should be. As mentioned, it's only the backup computer, so doesn't get a lot of attention.
Seems you may be introducing a host of unknowns with many IDE adaptors and the likes. If you're able to, it would be worth returning the A3000 to a fairly simple, basic, state. Including a real SCSI disk with FFS. It's slow, but it does work reliably enough to prove a point.
These kinds of problems can be a real pig to track down at times. So my suggestion would be to start with as simple system configuration as possible then work your way up.
Another stupid idea; if you have a large chest freezer, run the A3000 in there to prove a point with the heating theory. The inside case temperature will end up 30-40 degrees C less than what it currently is when operating at ambient room temperature. Most disks and other consumer electronics are only rated down to 0 degC, so if you put it in the freezer and get it running within 20 minutes or so, the heat generated will keep things above the minimum operating temperature.
As an example, I'm currently soak testing a HSDSL modem outside on top of a mountain here in Antarctica. Even though ambient is -20C, I can remotely see the modem's internal temperature is +24C. It's been working happily all week so far.
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Hi,
Assuming thats good, reseating chips-pushing on them is useless, pull them and reseat them(i doubt this is the trouble though) but we have 20 year old contacts here!Use a proper plcc puller, on those old sockets!. The pals and stuff on the side of the board you mention run quite hot normally,but usually run along happily that way.
I don't think heat is your problem but may aggravate the situation if you have a borederline component. Bad ram may very well be the trouble,and hot ram chips can be a sign of bad ram.This could cause most of the problems you mention and have effects system wide.
Mike
You were right about the ram being the culprit but so was the temperature factor.
I stripped down the A3000 to most basic running setup and starting reseating all non-PLCC chips (I don't have a puller yet). Nothing seem to work until after reseating the zip ram....the system was stable again I was able to boot, no more R/W errors or random crashes...etc. My problem might be unique to the A3000 since it uses Zip RAM which are prone to work themselves out of their sockets due to cycles of cooling & heating. I found this link by Robert Davis which explains the cause and the fix.
http://www.nyx.net/~rdavis/AmigaHints2.html#ZIPRAM (http://www.nyx.net/%7Erdavis/AmigaHints2.html#ZIPRAM)
The Deneb is working again with unexpected benefit which may be of interest to A3000 Deneb users. Even though I have Buster-09 and Deneb Flash ROM upgrade to support Buster-09 I was never able to use DMA mode without resulting in a ustable sytem. I tried using Deneb in DMA mode after the Zip RAM reseating fix and now DMA works! :) The system seems stable in Deneb DMA mode & I able to large filesize R/W without stability problems. Perhaps other weird A3000 Deneb related problems might be fixed by reseating all socketed components, especially the Zip RAM.
Thank you everyone for helping! :)
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Try adjusting the flicker fixer potentiometer and see if it clears up,these variable resistors do degrade over time.
mike
That fixed it, Thanks :)
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I'm not having much luck playing with SFS 1.279. I set things up via WinUAE and test them on the A3000. I tried suggested max transfers and mask values but still getting boot problems:
Mask:0xFFFFFFFF
Max Transfer: 0x7FFFFFFF, 0x1FFFE, 0xFFFE
What SFS values should I try for A3000 SCSI, SCSI-IDE bridge & CF combo?
It sounds like to me you have covered all the mask/max transfer values.is there any reason to suspect the new GAL's?
any news on this btw? find a fix yet?
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You were right about the ram being the culprit but so was the temperature factor.
I stripped down the A3000 to most basic running setup and starting reseating all non-PLCC chips (I don't have a puller yet). Nothing seem to work until after reseating the zip ram....the system was stable again I was able to boot, no more R/W errors or random crashes...etc. My problem might be unique to the A3000 since it uses Zip RAM which are prone to work themselves out of their sockets due to cycles of cooling & heating. I found this link by Robert Davis which explains the cause and the fix.
http://www.nyx.net/~rdavis/AmigaHints2.html#ZIPRAM (http://www.nyx.net/%7Erdavis/AmigaHints2.html#ZIPRAM)
The Deneb is working again with unexpected benefit which may be of interest to A3000 Deneb users. Even though I have Buster-09 and Deneb Flash ROM upgrade to support Buster-09 I was never able to use DMA mode without resulting in a ustable sytem. I tried using Deneb in DMA mode after the Zip RAM reseating fix and now DMA works! :) The system seems stable in Deneb DMA mode & I able to large filesize R/W without stability problems. Perhaps other weird A3000 Deneb related problems might be fixed by reseating all socketed components, especially the Zip RAM.
Thank you everyone for helping! :)
Glad to see you have fixed it! Just for some 3000T users out there.. i have fixed 5- a3000T's over the years with crashing/scsi problems and intermittent boot crashes by replacing the soldered in chip ram zips.This is not always the case,but if you have eliminated everything else then it may be a good place to look.I don't know if the ram was flaky from the start,or soldering had a effect on it or commodore got a bad batch of chips. On all 5 machines the chip ram was the same brand(i cant recall the exact part # and cant find my notes,but i think they were toshiba brand 256x4 zips) . this can literally make you pull your hair out chasing the trouble.Also a side note, NONE of the ram testing programs picked up on the ram as bad! I finally figured it out by loading up chipram until it crashed and burned.
I have also discovered quite a few different revisions of ramsey and dmac chips that don't play together nice. so realize if your messing with this stuff, a dmac2 isn't always the same as another dmac2 or ramsey4 as a ramsey 4 ;)
Over the years i have bugged castellen on a few things,and anthony has been infinitely helpful.You are a really good amiga resource!
Mike
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I tried using Deneb in DMA mode after the Zip RAM reseating fix and now DMA works! :)
So the Zip's weren't actually bad themselves... just were no longer making as good of a connection? Hmm... next time I have my A3000 apart, I'll try that. Can only currently use PIO mode in my system and I've got a higher revision Buster. Thanksf or the tip and glad you got your system all squared away :)
Kudos to Mike and Anthony too for their expert knowledge!
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So the Zip's weren't actually bad themselves... just were no longer making as good of a connection? Hmm... next time I have my A3000 apart, I'll try that.
I discovered while reinserting the 16mb of zips, it was too easy to accidently bend the legs. I used tweezers to carefully straighten any bent legs. Be patient during reseating & examine if all zips legs are properly inserted in their sockets. Be static safe.
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"hot" chips usually means over-voltage. The chips you mentioned do not even get warm in my Amiga 3000.
If the battery has leaked at all, then you will have problems with the Amber circuitry, even if you have removed the battery and cleaned the area. When the corrosion starts, it is like a cancer. It will continue to slowly eat away at the traces. This is why it is so important to find an Amiga 3000 motherboard with a battery that has NEVER leaked and remove that battery. Amiga 3000 motherboards like that are hard to find and command very high prices.
The Amiga 3000 computer was never really designed for expanding it. That is why it only has a 135 watt power supply. The most popular expansions people added to thier Amiga 2000 computer was Ram, SCSI, and processor boards. So, Commodore included all of that on the Amiga 3000's motherboard. They also included a FF/SD. Commodore did not think that people would need to install anything else, hence the 135 watt power supply. Amiga 3000s run nice and cool if you do not install any boards. The more boards you install, the hotter it runs. The Amiga 4000 is the same way, just not as bad as the 3000.
If you want to add a bunch of boards to an Amiga computer, get an Amiga 2000, 3000T or 4000T. These three Amiga models were actually designed to be expandable.
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If you want to add a bunch of boards to an Amiga computer, get an Amiga 2000, 3000T or 4000T. These three Amiga models were actually designed to be expandable.
OR purchase a BigFoot replacement power supply or mod your own from an orphaned PC ;)
Strange post. If a computer was not designed to be expanded, they wouldn't have included a Zorro II or III compatible busses with fancy Busters, let alone an accelerator slot.
Real issue here as you pointed out - is the power supply. Cheapo, weak power supply was a cost cutting measure to be sure. Commodore wasn't trying to dissuade people from upgrading their systems, just short changed some of those that wanted to upgrade at a later date on the initial purchase was all.
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"hot" chips usually means over-voltage. The chips you mentioned do not even get warm in my Amiga 3000.
If the battery has leaked at all, then you will have problems with the Amber circuitry, even if you have removed the battery and cleaned the area. When the corrosion starts, it is like a cancer. It will continue to slowly eat away at the traces. This is why it is so important to find an Amiga 3000 motherboard with a battery that has NEVER leaked and remove that battery. Amiga 3000 motherboards like that are hard to find and command very high prices.
The Amiga 3000 computer was never really designed for expanding it. That is why it only has a 135 watt power supply. The most popular expansions people added to thier Amiga 2000 computer was Ram, SCSI, and processor boards. So, Commodore included all of that on the Amiga 3000's motherboard. They also included a FF/SD. Commodore did not think that people would need to install anything else, hence the 135 watt power supply. Amiga 3000s run nice and cool if you do not install any boards. The more boards you install, the hotter it runs. The Amiga 4000 is the same way, just not as bad as the 3000.
If you want to add a bunch of boards to an Amiga computer, get an Amiga 2000, 3000T or 4000T. These three Amiga models were actually designed to be expandable.
Thats ridiculous. I've owned/fixed about 13 A3000's in the past,and alot of the chips he mentions run quite warm. There are many differences in chip revisions/board revisions and PAL chips that can cause it to be hot or not. I have had boards where the PAL's would just about burn you,but run on happily,and boards where those PAL's were just warm/hot.There are a good few board revisions out there and one size does not fit all when it comes to problems on the A3000.As dave haynie says,many A3000's that were not intended to be sold and were intended for just demo units but were sold because the 3000 was hot(no pun intended) at the time.
The 135watt power supply i find to be quite robust for most things except maybe a toaster flyer.Unlike power supplies today its actually rated to run at 135watts.this is more than enough power to run the motherboard and some cards/harddrive.. The reason we see failures is internal heat inside the case(add a fan or 2 with extra cards) and the power supplies are 20+ years old.Half the PSU's deemed bad and trashed were probably only in need of capacitors.Just because a PSU shows good voltages does not mean its good, leaky capacitors can let dirty power to the 3000 and cause all kinds of fun.
If the A3000 was not intended to be expanded it would of had zorroII/III slots and a video slot.
About the only point i agree with you mostly on is that battery leakage.So many good boards ruined. I will say i have some boards that have had leakage from over 10+ years ago that i cleaned up and fixed that still run fine today. Boards that get severe corrosion inside the layers are probably hopeless.Lets just hope amigans have the sense to save the chips off them before tossing the pcb.
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Real issue here as you pointed out - is the power supply. Cheapo, weak power supply was a cost cutting measure to be sure.
135W were pretty standard in the day (for a small box at least). Still got a PC-45/III PSU here - admittedly slightly older but it's just 110W.
I'd guess the mainboard with 16 MB RAM is still below 60W, so that'd leave plenty of margin for upgrades.
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Just took a quick measure: A3000/30 + 1 GB HDD + 12 MB ZIP + Merlin Gfx 4 MB + A2065 + Maestro = 97W primary (108W peak, 92W with HDD powered down).
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Yeah... I'm probably rolling my perceptions of past C= power supplies here, but damn were some of them junk. A1200's being weaker than the A500's (WTF?!) and both needed extra care paid to 'em as far as a user adding to their system. Then there was the 8-bit line whose non-user serviceable brick that most C64's and all C64c's were shipped with, was not designed to power much more than a cartridge or tape drive. Heck, you're not even supposed to plug one of their REU units into 'em without modding the REU or replacing your power supply. That's what I've read anyway. Have yet to even plug in my 1750 and am kind of scared to since I've read all the horror stories.
Think I'll post a new question instead of littering this thread :)
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Yeah... I'm probably rolling my perceptions of past C= power supplies here, but damn were some of them junk. A1200's being weaker than the A500's (WTF?!) and both needed extra care paid to 'em as far as a user adding to their system. Then there was the 8-bit line whose non-user serviceable brick that most C64's and all C64c's were shipped with, was not designed to power much more than a cartridge or tape drive. Heck, you're not even supposed to plug one of their REU units into 'em without modding the REU or replacing your power supply. That's what I've read anyway. Have yet to even plug in my 1750 and am kind of scared to since I've read all the horror stories.
Think I'll post a new question instead of littering this thread :)
the Wedge amiga power supplies were not good. they were marginal at best,the 500 one the better of the bunch.Its not hard to overload a 500psu tho with some modest expansion.
The c64 power supplies were really bad(the potted bricks). Some early ones were repairable tho. most tried to kill the c64 when they died. The 1570 reu came with a c128 powersupply modded with a c64 plug. it was a power hog.
I don't recommend you try and use the reu with a stock c64 brick.either get a c128 psu and mod it with a c64 din plug or build a suitable supply.