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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: David Wright on September 20, 2017, 11:22:10 PM
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No video but black screen on boot up. Took out all the video toaster and relevant boards, nothing.
I assume that blue barrel is my battery, some leakage but doesn't appear to be on board. Still would like to know the easiest way to remove.
Also, what is the chip added with the 3m cable, chip ram upgrade?
Any basic procedures to diagnose this?
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Also, what is the chip added with the 3m cable, chip ram upgrade?
Looks like a ROM switcher to let you switch between 1.3, 2.x and 3.x ROMS at boot time.
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The cable in your picture is connected to a ROM switcher. I would remove that and try booting off of just one ROM. If that one doesn't work, try the other. It may be that one has failed - but hey, at least you have a swap/test component. ;) Remove all boards (including that accelerator I can see in the picture) and try again.
Also, get that battery out ASAP and clean the area as is described extensively in this forum and others. Give it a wiggle till it breaks free or side cutters work well.
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I did try removing all components but not rom switcher, will try it.
Also noticed to my surprise a megachip expansion on board.
Should I be able to see floppy light activity when inserting disk? No led light on hd either, spins but nothing else.
I will try the rom switcher next.
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Remove Accelerator HDD and everything but floppy. You should work to get an insert floppy disk and floppy drive "clicking" first before moving on.
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Removed everything but the two floppies, and no insert disk, no click, no display and nothing happens when I insert floppy.
To summarize,
I removed accelerator, scsi card/HD, and video toaster.
Turn on, still black, no clicking or insert prompt. No activity when I insert floppy.
I have (from what you tell me) is a rom switcher and a Mega chip chipram expander. Both run a clip that attaches to , I presume, the Gary chip.
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Have you tried pulling out the socketed chips and reseating them?
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I'd remove the battery (yes that blue barrel) , clean and check traces
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As others have said, +1 for clean and reseat every socketed chip, including your Megachip adapter.
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Definitely reseat the chips. My A500 has a chip come loose every time I move it. One of the CIAs has DF0: selector mod that uses a machine socket for the CIA to sit into on top of the mod's PCB. Without fail, if I should pick the 500 and move it, this comes just slightly loose, and the machine will not boot. I open it up, reseat it, and, it boots like a champ.
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Leakage from the battery will often form corrosion on the legs and sockets of the CPU closest to the battery. Extremely rare but also possible is the bad battery causes a short. Carefully cut the legs on that battery and get it out before it does more damage.
If you're handy with tools and fine details, pull the CPU, carefully clean the legs with an eraser or very very fine sand paper (600 grit or higher). Next check the CPU socket closest to the battery. These types of sockets are not easy to clean, often I just replace them. But if the corrosion is not terrible in there, you can use a sewing needle to carefully scratch at the inside of the sockets to clean the worst part of any corrosion. The sockets should look silver, not green or dark. After it's all as clean as you can manage, slowly replace the CPU being careful not bend any of the pins.
I hope you get it running again.
Plaz
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Here is photo after battery removal.
Reseated a few chips including rom switcher.
Nothing yet, will reseat and clean cpu.
Thanks
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No video but black screen on boot up. Took out all the video toaster and relevant boards, nothing.
I assume that blue barrel is my battery, some leakage but doesn't appear to be on board. Still would like to know the easiest way to remove.
Also, what is the chip added with the 3m cable, chip ram upgrade?
Any basic procedures to diagnose this?
Do you have any history on the 2000 ?
What are you displaying on and how are you connecting to the display ?
The ROM may be at fault and may just need say one of the ROMs put back in to test. The CPU would throw up a colour in truth. You say there is no LED light from power so is the power getting to the board ? Sounds dead to me.
I just gently rock the battery back and forward and eventually the thing just snaps off. Dunno how you removed . er don't do that with a 3000T though.
I have a 2000 that throws up a grey screen and appears to be dead but I just tap the side of the computer a couple of times and when I reboot she is fine. Its a dodgy card on that.
Have a look under the power supply to see if you can spot any dodgy connectors to chip legs. Happens.
Good old dust. Strip back to a basic 2000. Reseat the CPU. I wouldn't do too much as you kinda just add to problems which may not be there. Could be the ROM switcher.
Great bit of kit. Haven't had one fail on me yet. Been using one of mine all afternoon today.
Have fun
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I did rock the battery out, kind of indelicate I know. I have a 4000 that needs done too, can I just snip that out?
This man gave me a lifetime of his Amiga video business. Tons of disks, cds, manuals , original boxed graphics and productivity. Huge, I say.
The 4000 works fine now that toaster hardware is out and displays quite nice with hdmi to scart convertor.
Back to the 2000. I was thinking of taking my Vampire out of the 500 to see if that works and disable the rom switcher. I don't know if Mega chip is an issue either. Power does spin the Ricoh Reader drive (never seen that before) which is in the cd drive bay. When HD card and drive were in zorro slot , power was getting to that.
I did see a bit of green corrosion a few pins of the cpu which I cleaned as best I could.
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I wouldn't install the Vampire into a corroded socket.
If you saw corrosion on CPU legs, you can bet the inside of the CPU socket is corroded too and needs to be replaced.
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I did rock the battery out, kind of indelicate I know. I have a 4000 that needs done too, can I just snip that out?
This man gave me a lifetime of his Amiga video business. Tons of disks, cds, manuals , original boxed graphics and productivity. Huge, I say.
The 4000 works fine now that toaster hardware is out and displays quite nice with hdmi to scart convertor.
Back to the 2000. I was thinking of taking my Vampire out of the 500 to see if that works and disable the rom switcher. I don't know if Mega chip is an issue either. Power does spin the Ricoh Reader drive (never seen that before) which is in the cd drive bay. When HD card and drive were in zorro slot , power was getting to that.
I did see a bit of green corrosion a few pins of the cpu which I cleaned as best I could.
You should catalogue your acquisitions and make a note of what went with what before you forget. It is great getting a collection from someone cus you have their world in a kinda snapshot. Some of the items you discussed like the reader sound fascinating. Maybe you could post some images.
The 2000 may only be a minor thing that is blocking you out. I have three 2000s that I run each day with various degree of issue and I get grey screen, software failure, just a red power light and various other issues. I tend to bulldoze through them and it seems to keep them alive. Pretty brute hard headed the 2000. When you know the previous owner you can sometimes discuss issues. The one 2000 I have I know the guy and he tells me all kinds of things to look out for.
Have fun.. Like I say I wouldn't be too drastic with the changes cus in truth the problem is just one thing. Just need to find it. And take the pictures, always good to look at.
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Yes, there is a life represented here with what I received. This man retired from teaching in his 50's and started a video production business over 25 years ago with Amigas. Eventually he went all Mac but the first thing we talked about is the sad day when Commodore was no more. He upgraded often and consistently, with everything imaginable. There a few still shrinkwrapped audi devices and software like Lightwave.
HE WAS GOING TO THE RECYCLING CENTER WITH THIS!
Anywho, I reseated more chips, cleaned more, took off rom switcher. May have to look into a replacement MB. I want this back with that nice accelerator, Video toaster and to see what is on those 50mb Rickoh cartridges.
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No need to replace the MB! Send it to Acill here on this forum, you will get a fine MB back.
He's in California but sometimes has to travel so it may take a few weeks.
I will be sending mine there as soon as I get this old Marantz receiver off my bench and have room for disassembly. First the A2000 then the 4000T. Hope you have a rev 6.2 or better.
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Revision 4.2. Not good?
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Not sure of what incompatibilities or drawbacks that rev may have so I will let others comment on this. Since it has been upgraded there may not be any...?
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Took out MB and took this photo of back. Note the battery area but also the attached wire on the bottom right, some kind of trace repair?
(Battery is top, just left of center)
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Took out MB and took this photo of back. Note the battery area but also the attached wire on the bottom right, some kind of trace repair?
(Battery is top, just left of center)
Hi!
Had you check the TICK signal from de PSU?
Try start up without this signal from the PSU, only changing the J300 jumper position.
I had this same problema during my PSU MOD adapting a PCAT PSU.
Regards,
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Tried the j300 jumper, no luck.
Looks like I might piece this thing out, not worth the money to fix.
I have tried:
Disabling rom swithcher and using one rom
Removed Megachip and used just the agnus
Reseated cpu and most chips
Cleaned as well as possible
All with just psu and floppies attached nothing more
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Tried the j300 jumper, no luck.
Looks like I might piece this thing out, not worth the money to fix.
I have tried:
Disabling rom swithcher and using one rom
Removed Megachip and used just the agnus
Reseated cpu and most chips
Cleaned as well as possible
All with just psu and floppies attached nothing more
Could you tell if the Power LED or CapsLock Led blinks when you power on the machine?
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An update without a change as I came back to this.
Replaced rom swithcher with one rom , a new 3.1
resocketed and cleaned cia chip.
I took better photos of front and back. That wire on the back bothers me. I show in photo: looks like to an expansion socket ( don't know what that is) to the first Cia chip.
I keep reading that if the system hangs at a light gray chip, cpu is ok but possibly something with Cia chip. Which keeps bothering me with that wire in the back. What is that for?
Also no Df0 light comes on or click.
(thanks Acill for the offer, but too much money to invest in another amiga, just want to learn on this one)