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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Tumbleweed on November 06, 2021, 04:39:47 PM
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Hi all,
After getting my A3000T running again its been working fine for a few months and then I started getting random "recoverable alerts" just after WB screen appears and when I open certain apps - iBrowse. Was an annoyance and I thought it might be software related. I did a clean install of OS3.2 and it seemed to be ok until a couple of days ago when the 3000T started suffering recoverable alerts and this morning critical failures (screen shot below) before booting WB and got stuck in an reboot cycle.
The guru I think is telling me a problem with memory - chip mem?
I have run a couple of different memtests (memcheck and ziptest from aminet) and all show ok but maybe these are giving me false positives as the machine has booted fine prior to these being run.
My plan is to remove the Zip ram but want to avoid pulling all of the chips as they are fragile and I want to avoid bent pins or worse broken pins. Before doing so is there anything else I can check in software to identify a problem with the memory?
Weed
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is there anything else I can check in software to identify a problem with the memory?
Use Amiga Test Kit (boot from floppy disk) and use the 'Test All Memory' function.
https://github.com/keirf/Amiga-Stuff
Let it run overnight and see if there are memory problems reported the next day.
Also try applying gentle pressure to the ZIP memory (both fast memory and chip memory) while the test is in progress and see if that triggers a memory error or a crash of Amiga Test Kit. If this happens, there's usually a contact problem with one of the ZIP sockets. This can be tricky to track down exactly where it is, so remove all ZIPs from sockets, apply isopropyl alcohol to the sockets, then carefully re-insert the ZIPs while the alcohol still wet. Give it half an hour or so for the alcohol to evapourate before powering on. Don't mix up the chip and fast memory ZIPs as they will be different sizes.
Just to state the obvious, always double check the ZIP polarities before inserting them, check the pins are all aligned, and check pins are *between* the socket contact pairs before pressing them in place. As opposed to employing a mutant gorilla with a sledge hammer as many people seem to do when fitting ZIP memory.....
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The location shown (08003778) is neither in the chip RAM (00000-1FFFFF) or the Zip RAM (07000000-07FFFFFF).
08000000 and up is the RAM on the CPU card.
https://amigacoding.com/index.php?title=Amiga_memory_map
Zip RAM is physically fairly robust, it's really fragile to static electricity (use an earthing strap connected to your wrist and and earth point).
I've blown up multiple Zips with just one fleeting touch on a pin while not earthed.
One way to apply pulling press without crushing the chip is a sheet or rubber or masking tape and short nose pliers.
Thumb and forefinger and rubber gloves if you got a lot of finger pressure.
But I think it's the simm RAM on the Cyberstorm Mark 3.
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Thanks both.
I've a CSMKII with 128MB maybe its a dodgy SIMM or one has come loose. Ill check and reseat them later today. The RAM test I ran overnight with no issues. I'll leave the machine off for a few hours and then re-run overnight again. The issues seemed to be when I booted up from cold. Once booted it seems to be much more stable.
Best.
Weed
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Left it off for a few hrs. Switch on - same issue red guru as before, followed by a reboot loop. Switched off. Removed the 5 1/4 drive cage and re-seated the SIMMs on the CSMKII. Switch on and booted off floppy into Amiga Test Kit. Removed floppy rebooted fine off the SCSI2SD.
Will run more tests - maybe an ill-seated SIMM?
Weed
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All looked ok until I refitted the drive cage. I got a recoverable alert when starting iBrowse. Switched off. Removed drive cage and then removed the ram from the CSMKII. Switch on - no boot - black screen.
I then removed all boards - RTG, Network cards and the CSMKII. Switch on. No boot - black screen.
Removed 1MB of chip ram - the other 1 MB is soldered to the board. Switch on - boot and get the 3.2 boot screen.
If its a problem with the 1MB chip ram - that may be down to user error - I suspect I bent a pin when reinstalling it after the board was fixed. There is one ZIP with crumpled leg (its shorter than the others). Ill try straightening the leg, but if I need to replace the ZIPs - can you still get them easily?
Weed
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Straightened the bent leg and refitted the ZIPs. Switch on - black screen. Removed all the chip mem ZIPs again switched on - black screen. I can here the drives clicking - floppy and the SCSI CD Rom is active - its almost as if its stuck in a reset loop. Monitor is flickering coinciding with the polling of the drives.
Caps lock key does not go off after more than a dozen pushes.
What's really odd is that after connecting the cables for the drive LEDs and the key lock, switching on, then off and then removing the cables for the LEDs its booting to the OS3.2 kickstart. Inserted floppy with Amiga Analyzer and can now run the memory tests. CHIP Ram test - 30+ rounds all ok.
With the me tests looking OK. I reinstalled the MKII - no memory installed on it. Switch on blackscreen. Soft reset a couple of times - no rainbow colours to show the CS as active. Then after switching off and a soft reset the CS rainbows appeared. Booted into Amiga Analyzer and now I can run the tests again. Could this be a PSU issue?
Installed the SIMMS in the CSMKII and now its in a continual reboot cycle.
Weed
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Could be Psu, could also be reset circuitry having issue on a cold start.
That Caps Lock light sticking on is odd, usually controlled by the keyboard controller inside the keyboard.
I think you might have more than one problem here. I would try powering on without the keyboard to see how far it gets.
EDIT: Using DeOxit on CPU and RAM connectors might help. The Cyberstorm (040 version) hasn't got much in the way of power smoothing capacitors, very much depends on everything else to behave.
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Pat thanks for that. Th reset circuitry is not something I had thought about. The MB has been recapped and repaired. Was working fine after I rebuilt it until the last couple of weeks when I started to get the recoverable alerts and then the full software failure guru.
The initial symptoms were that it wouldnt boot straightaway - had to do a soft reset. Then I found I had to do more frequent soft resets to get it to boot from cold. The next thing I started to get was the red guru, and now its struggling to even boot - gets into this reset loop which it doesnt get out of.
The CS should be ok as I ran it in my A3000D and its works without any issues.
Edit: Just after posting I wiggled the CSMKII. Switched on and it booted straight into Amiga Anlayzer and everything looks ok. If I switch off and then switch on though Im not confident it will boot.
How can I test the reset circuitry? The issue seems to be when boot from cold, but once booted its mostly ok (maybe the odd recoverable alert though).
Weed
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Could be Psu, could also be reset circuitry having issue on a cold start.
That Caps Lock light sticking on is odd, usually controlled by the keyboard controller inside the keyboard.
I think you might have more than one problem here. I would try powering on without the keyboard to see how far it gets.
EDIT: Using DeOxit on CPU and RAM connectors might help. The Cyberstorm (040 version) hasn't got much in the way of power smoothing capacitors, very much depends on everything else to behave.
I used this contact cleaner to clean the board before I rebuilt it. https://www.toolstation.com/wd-40-specialist-contact-cleaner/p87848 (https://www.toolstation.com/wd-40-specialist-contact-cleaner/p87848) I also soaked the ZIPs in Isopropyl Alcohol before I fitted them. No harm in doing again though. Ill try the DeOxit this time.
EDIT: I ran AmigaMARK - Memory Benchmark and got this:
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How can I test the reset circuitry? The issue seems to be when boot from cold, but once booted its mostly ok (maybe the odd recoverable alert though).
Weed
This is not straightforward on an a3000T. Ideally means removing the motherboard. And tracing the signal with a logic probe. Working from a schematic.
On powerup, the motherboard reset signals waits for a shortwhile, then applies a momentary low pulse into the Rst line. This gets fed around the board to different components.
Chips with power on them start in an "undefined" state, Rst clears them to an initial zero point. The keyboard circuitry for reset feeds ino the same system.
I think you have more than one problem here, so probably a good idea to just reset on power up, then look for the memory fault.
The think with cleaning connectors is - you have to clean both of them, and oxidation builds up on BOTH sides.
Board cleaner does not remove oxidation from pin contacts and solder points. You have 30 years of copper "rust".
OK, this may not fix your memory problem, but it will help to keep a machine reliable.
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EDIT: I ran AmigaMARK - Memory Benchmark and got this:
OK, that definitely points the finger at a chip RAM problem.
If you can get it to do that consistently, at least the first 512kb is OK.
It could be one or more of the 74245's looking after the address lines rather than a defective ZIP.
A little odd that that AmiTestKit didn't find a problem.
Another thought... is the CPU card suppoted by risers or is it just plugged into the slot? Might be a big part of your issues.
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Thanks Pat. The CSMKII is supported with risers. The board is held in place with two screws.
Checking out the reset circuit is going to be a challenge as I dont have a logic probe, the schematics or knowledge on how to do it. The only chip mem on the board is the ZIPs soldered in place as I didnt refit the ones I removed from the sockets. Think my soldering skills are sufficient to remove / replace these though.
Its very odd though. When the machine starts it runs fine for hrs without any signs of memory problems. I can run the memory diags for hrs without any errors being reported. Checkmem, CheckmemHD, Ziptest, Amiga Analyzer all show no errors.
Edit: Booted fine first thing this morning. Went to change screen mode and got a recoverable alert.
from the error code looks to be:
0x0100000F Recoverable Memory header not allocated. Usually an invalid address passed to FreeMem()
So by the looks of it a memory issue or a memory controller issue - could that be a problem with Agnus?.
Thanks for your help.
Weed
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Could be but unlikely - rarely do you get an intermittent fault.
Agnus does control the RAMOE (Ram Output Enable) which feeds to all the Chip RAM components through. Goes to U203, a 16L8D, and comes out on pin 16.
However, if it wasn't working at all, you should get a green screen rather than a recoverable alert,
Likewise the data pins, you have a display, therefore all the data pins are OK.
Which is why I expect it's the 74245s that select the right chip combination from the address. It seems the low end of chip RAM is OK, but there can be issues with the upper part of chip RAM.
https://www.amigawiki.org/dnl/schematics/A3000T.pdf
Has the Psu ever been serviced, recapped or replaced? That could be the root cause.
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Thanks PAT. Ive not serviced the PSU. its where I'll start looking.
I ran it all day today - running the memory diag from ATK v1.18. It generated an error screen shot attached. This doesnt mean an awful lot to me other than it looks to be an error on the 32 bit bus.
Any ideas as to how I should interpret it?
EDIT: And after a short time - chip ram = 0 Other mem = 4,160,555,704 (see screenshot of WB). I soft reboot and now its back into a reset loop after power off / on.
Best.
Weed
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OK, that was definitely in the motherboard fast ZIP memory (07000000-07FFFFFF). Looks like a bad ZIP or maybe just loose.
What confuses me is only 1MB of chip RAM. Do you have half your chip RAM sockets empty?
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OK, that was definitely in the motherboard fast ZIP memory (07000000-07FFFFFF). Looks like a bad ZIP or maybe just loose.
What confuses me is only 1MB of chip RAM. Do you have half your chip RAM sockets empty?
I removed the socketed CHIP Mem ZIPS - thinking the problem was in chip mem. I didnt replace them. I have got the machine running mem diag on the fast ram using ATK (it booted fine after I left it off for a while). I will run overnight and see what happens. If it is the fastmem I will remove the fastmem ZIPs. Its apian as there are alot of them and its easy to damage them when removing and that maybe the source of the problem as I had removed them and refitted them after soaking in isopropyl alcohol - I did ben a few pins and it took me a few attempts to get them all seated properly.
I did some googling and reading past threads on A.Org and EAB. One suggestion was to check the tick signal from the PSU or switch the source using J350. I might give that a go tomorrow depending on the results of the ATK mem test.
Weed
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Might be you got a chip RAM ZIP mixed up with a fast RAM ZIP?
The 2 are different sizes (256K X 4 for chip, 512K x 4 for fast).
Checking the tick line is a good plan, as is a recap on the Psu.
The timing jumper is necessary if you replace the Psu entirely, only big box Amiga Psus have a tick output.
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I ran ATK overnight and it flagged a mem error in fast RAM as a I suspected it would. Slightly different error from the one flagged yesterday. So feels like FAST Ram is the issue. This kinda makes sense as I did bend pins when I installed the ZIPs and it took me a few attempts to fit them.
My plan is to remove the ZIPS one bank at a time and re-test using ATK.
PAT that is a very good suggestion re me mixing up the ZIPs. When I removed them I stored them in separate containers one for the Chip memory and the other for the FAST. They then sat for a long time (a few years) - maybe they got mixed up during that period but I'll double check.
EDIT: CHIP RAM ZIPs are all 256 modules. MB81C4256A-70PSZ 9250 D13Z is what is printed on them. Manufactured in Singapore.
I tracked down ZIPs from a UK seller on eBay last night and ordered 8 ZIPs. These look to be the static column type I think going by the spec - 258 as opposed to 256 which I read signals that they are static column.
TC514258AZ-80,TC514258 20PIN ZIP, 256K x 4 1M DRAM
Thanks for your help Pat I really appreciate it and I feel as though I am now getting somewhere. :D
Weed
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Update:
I removed the Fast Ram ZIPs - ended up taking them all out as I discovered that I had bent quite a few pins when I had fitted them (see PIC). These are some of the better ones.
No will rebuild one bank at a time and see if I can correct the bent pins. If I cant salvage them I'll end up with less on board Fast Ram. Not a prob as there is 128MB on the CSMKII and on a positive note I now have an excuse to get one of these https://icomp.de/shop-icomp/en/produkt-details/product/bigramplus.html (https://icomp.de/shop-icomp/en/produkt-details/product/bigramplus.html) ;D
EDIT: Fitted the Chip mem ZIPs - booted. Got the kickstart screen. Ran ATK - 2MB Chip found. Ran the mem diag - all good after 40+ rounds. Switch off. Populated Bank 0 with Fast Mem ZIPs. Switch on - no boot. Black screen. Soft reset - black screen. Switch off/on - black screen. Reinstalled CSMKII - switch on Rainbow bars but then black screen. CSMKII is working as I get the rainbow when I soft reset but then it progresses no further. I get a black screen.
Removed chip ram ZIPs - boots. Up and running. Run ATK - 1MB memory found (correct all ZIPs removed and no CSMKII). Run mem test all looks ok.
Fitting the ZIPs into bank 0 seemed to trigger the problem. Its all very odd. Will try adding the chip mem ZIPS with the CSMKII and not populate the FAST ram.
Weed
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Yeah, those ZIPs are a PITA.
It's tricky working them into an A3000D, putting them in sideways on a Tower... welll...
I could be wrong, I thought you had to have a little bit of motherboard fast RAM on these to keep the onboard scsi happy or similar.
I can httpsee why people fit simm adapters in the ZIP sockets. Much lehttpshttps hassle.
You might have a damaged or maybe corroded ZIP socket rather than a chip,
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https://www.pcbway.com/project/shareproject/Amiga_3000_Tower_SIMM_ZIP_Ram_Adapter.html
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ZIPs are areal pain as Castellen pointed out:
"Just to state the obvious, always double check the ZIP polarities before inserting them, check the pins are all aligned, and check pins are *between* the socket contact pairs before pressing them in place. As opposed to employing a mutant gorilla with a sledge hammer as many people seem to do when fitting ZIP memory....."
the pins are so fragile and even when taking care its easy to bend them. For the 3000T the CHIP mem ZIPs arent too bad as you can get easy access to them. The FAST mem ones though are best populated with the board outside the case as the second bank is close to the floppy drive and CD compartments.
The ZIP to SIMM adapters are a neat solution but they are hard to find and for some they get in the way of the CPU card. I came across the link to the PCBWay website. I might have a go at that - need to get a decent soldering station though. Would make a neat mini project.
After a lot of testing various combinations of CHIP ram 1MB, 2MB CPU CARD no FAST Mem Zips etc and testing with ATK I have it booting happily into WB with no on-board FAST mem but with 2MB CHIP and 128MB on the CSMKII.
Will let it run overnight with ATK as before and fingers crossed no errors flagging when I look at it in the morning. :D
I also tracked down some ZIPs for the FAST mem on eBay - almost the same as the original ones but slightly slower 80ns vs 60ns. The CHIP zips are 70ns. Does it make a difference that the CHIP and FAST operate at different speeds?
Weed.
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After a lot of testing various combinations of CHIP ram 1MB, 2MB CPU CARD no FAST Mem Zips etc and testing with ATK I have it booting happily into WB with no on-board FAST mem but with 2MB CHIP and 128MB on the CSMKII.
Will let it run overnight with ATK as before and fingers crossed no errors flagging when I look at it in the morning. :D
Fingers crossed it will be OK.
I also tracked down some ZIPs for the FAST mem on eBay - almost the same as the original ones but slightly slower 80ns vs 60ns. The CHIP zips are 70ns. Does it make a difference that the CHIP and FAST operate at different speeds?
Weed.
For best performance, you want the fast ZIPs to all be 60ns or faster static column. I don't advise mixing different speeds and different types (static column OR fast page).
Chip RAM has to be 80ns or faster.
However, chip and fast can be different speeds, bearing the above in mind.
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Oh, if you want to check RAMsey settings for motherboard fast RAM;-
http://eab.abime.net/showthread.php?p=1026344
Best done with no fast ZIPs installed.
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Thanks Pat. I didnt know such a thing existed. Ill try it out tomorrow depending on how the mem tests go over night. :)
Very much appreciated.
Weed
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Ive not serviced the PSU. its where I'll start looking.
This issue does have signs that it could be related to excessive noise on the 5V supply, or possibly heat related. If you have some way of looking at the AC component on the 5V supply (e.g. an oscilloscope), you'll immediately see the state of the power supply. Expect less than 50mV of AC noise on the 5V line when measured at the main board power connector, and the DC component between about 4.7V - 5.2V.
I've just noticed that you have a CPU board. To rule that out as a possible contributor, I'd suggest operating the A3000T with the onboard 68030 and memory and *without* the CPU board fitted to see if there's any change in operation.
What were you hoping to achieve with the reset line? Unlike most Amiga models, the A3000T reset signal is generated within the power supply, not on the main board. At power on, reset stays low until the 5V supply is stable, then reset is set to 5V and the system runs. Worth noting with the A3000T is if reset rises too quickly (it isn't delayed when the 5V supply comes up), then the fast memory controller (Ramsey) isn't initialised correctly, and you can end up with 0MB or 4MB of fast memory instead of whatever you have fitted.
If the main board has no sign of booting, then it's worth checking that reset/'power good' is at 5V for starters. But whatever is happening on the reset line won't be causing your software errors.
Also on the A3000T, reset is connected to the front panel key switch. I had a customer recently where the key switch had been butchered and was permanently holding reset low.
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Cheers Castellen. I ran ATK overnight. 3000T configured as follows:
1. CHIP mem populated with 2MB. I reinstalled the ZIPs I removed.
2. CSMKII 060 with 128MB SIMMS
3. No on-board FAST mem
Ran the all memory diag. No issues reported after 50+ rounds. Yesterday ATK reported errors in FAST mem with on-board FAST ram ZIPs populated. No probs reported today. I suspect I damaged the ZIPs / sockets when reinstalling them. I have new ZIPs arriving at end of this week. So may try them. I also have a 3000D so I can use that to test the ZIPs I removed from the A3000T.
Ill have a look at the PSU. I dont have a scope though but can check voltages using my multi-meter. Maybe I should recap the PSU. Not sure how onerous a task that would be but I am ok using a soldering iron so long as I am clear on whats to be removed and replaced.
Best.
Weed
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Been a while since last posted on the probs I had with my A3000T. After removing the FAST Ram ZIPs Ive had no probs. Today I received a new Super Buster -11 (from Analogic) which I replaced the existing -07 version and fitted the BIG Ram Plus (from Alinea). Ive not got an immense 128MB + 256MB of FAST RAM.
I remember when I got my first A500 with 512k pf RAM. This was huge as I had a C16 back then with 16k. I then upgraded the A500 with a 1/2 MB trap door expansion to have what was mammoth back then 1MB. Ive now got 384MB plus 2 MB chip :D. Now what can I do with it?