New member; Amiga owner since the 90s

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zapata07

New member
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Apr 3, 2021
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Country
Portugal
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Oeiras
I initiated my journey with computers when I got a ZX Spectrum. Incredible stuff it was. Also quite fragile, I remember that more than one broke and had to be replaced.
Afterwards I had an Atari ST but that didn't last long as I soon discovered the Amiga 500 and fell in love. So advanced in its capabilities. Multitasking! Incredible!

When I saved for it I got myself a second hand Amiga 2000 HD with the A2630 board. It served me well for several years. I played games on it but it was also with it that I started using BBSs. Using AMOS I even wrote a program to download messages from them. It even had a builtin text editor! So many memories...

After several years I got married, work, kids and interest in the Amiga waned. It was boxed (still the original box!) and kept there for over 20 years. I kept reading stuff about the Amiga evolution but only two weeks ago decided to unbox the 2000 and fire it up. To my dismay it no longer started! It was a sad moment. I read a lot about it, watched videos and tried to find information that could help solve the issue. I learned about leaking batteries and removed the Varta. It hadn't yet leaked but it sounds safer to scrap it. I don't see any capacitor damage, the board looks pretty clean. I unseated all removable chips and cleaned them. Still no evolution: The screen shows dark grey, then light grey and the returns to dark grey, light grey and repeats and repeats.

Probably it's a minor thing but my knowledge is very limited and I don't know what else I can do which saddens me a bit. I noticed that almost all chips get warm, except for the Gary one and. This is not normal, right, and probably an hint that something is wrong around that area.

Anyway, I'm looking around trying to decide what to do next: just box the machine again and forget about it or find someone to help me.

If someone has any advice I would appreciate it. Thanks.
 
Based on the sequence of colours you are seeing, it hints at a possible CIA chip problem. Light grey usually turns to white if the CIA chips are OK just before the Workbench screen comes up. I suggest that you check carefully for track damage around the battery area, as the CPU, CIA chips and Gary may be located nearby (it depends on the board revision number).
 
Hi , Welcome :thumbsup:

---------------------

PT - Boas , Muito bem vindo ao Amibay.
 
Based on the sequence of colours you are seeing, it hints at a possible CIA chip problem. Light grey usually turns to white if the CIA chips are OK just before the Workbench screen comes up. I suggest that you check carefully for track damage around the battery area, as the CPU, CIA chips and Gary may be located nearby (it depends on the board revision number).


Thanks for the suggestion. Do you know if the CIA chips should get warm to the touch? I noticed that the one on the left didn't appear to get warm at all, while the other did get a bit warm. Then I swapped them and it appears the one who didn't get warm still doesn't, while the other still gets a bit warm. But I want to make sure if it's indeed the chips before buying one and then it's not that.

This is a 6.2 motherboard, so the CIAs and the GARY chip are far from the battery area. But I will try to check, with a multimeter, if there's continuity for all those three chips. I'm not accustomed to do it but I have a friend who knows more about this stuff and hopefully we can find something.

To the other member who suggested removing and reinserting all chips, I already did that but, unfortunately, no change at all. Portuguese: Obrigado pela ajuda!

A couple more things:

1. I remember that, some time ago, when the machine still booted properly, both floppy disk drives were unable to read diskettes. They whirled but nothing. Could it be due to the diskettes no longer being functional, as they were over 20 years old? Or maybe it's the drives themselves? But it's strange that both went down at the same time.

2. If the drives are non functional does it make sense to try to find a replacement or would it be better to go the Gotek route?

Oh, and is it better to move this type of discussion to another sub-forum?
 
Floppy drives not reading is all pointing towards a faulty CIA chip, possibly the odd CIA. I doubt that both floppies would fail at exactly the same time. You might find this troubleshooting chart useful.
 

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[TABLE="width: 1010"]
[TR]
[TD]RED[/TD]
[TD]Kickstart ROM error[/TD]
[TD]Two ICs in A1200, A3000, A4000[/TD]
[/TR]
[TR="bgcolor: #F2F2F2"]
[TD]BLUE[/TD]
[TD]Custom chip problem[/TD]
[TD]Denise Paula Agnus[/TD]
[/TR]
[TR]
[TD]GREEN[/TD]
[TD]RAM error[/TD]
[TD][/TD]
[/TR]
[TR="bgcolor: #F2F2F2"]
[TD]YELLOW[/TD]
[TD]Above problems combined[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]LIGHT GREEN[/TD]
[TD]CIA (U7/U300) problem[/TD]
[TD][/TD]
[/TR]
[TR="bgcolor: #F2F2F2"]
[TD]BLACK[/TD]
[TD]CIA (U7/U300) problem[/TD]
[TD]If not booting[/TD]
[/TR]
[TR]
[TD]DARK GRAY[/TD]
[TD]Hardware tested OK[/TD]
[TD][/TD]
[/TR]
[TR="bgcolor: #F2F2F2"]
[TD]LIGHT GRAY[/TD]
[TD]Software tested OK[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]LIGHT GRAY[/TD]
[TD]CIA (U8/U301) problem[/TD]
[TD]Stops at gray, CIA defective[/TD]
[/TR]
[TR="bgcolor: #F2F2F2"]
[TD]BLACK/STRIPES[/TD]
[TD]ROM or CIA[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]No video[/TD]
[TD]R406 or R215 open R406=1 ohm R215=4.7 ohm[/TD]
[TD][/TD]
[/TR]
[TR="bgcolor: #F2F2F2"]
[TD]Video scrambled[/TD]
[TD]Agnus or Denise defective[/TD]
[/TR]
[/TABLE]
 
DISK DRIVE PROBLEMS

Clean heads and check for excess dust in drive. Clean out dust and try again. This may eliminate the problem. In the followings tests, a known good drive should be substituted to eliminate the drive as the source of the problem.


  1. Internal/external drive not recognized. Probable causes:
    • 8520 U8 Even CIA (U301 A2000)
    • F4 4 amp pico fuse bad (A2000)
    • F3 4 amp pico fuse bad (A2000)
  2. Motor problem
    • 8520 U8 Even CIA (U301 A2000)
    • 5719 U5 Gary (U102 A2000)
    • 74LS38 U 36 (U203 A2000)
  3. Not recognizing disk change:
    • 8520 U7 Odd CIA (U300 A2000)
  4. Write protect problems:
    • 8520 U7 Odd CIA (U300 A2000)
  5. Read/Write errors:
    • 8364 Paula U3 (U200 A2000)
    • 68000 U1 (U100 A2000)
    • 8370 – 8372/8375 U2 (U101 A2000)
  6. DF1 A2000 not recognized:
    • J301 open (must have jumper installed)
    • 8520 U301
    • 74F00 U900
    • 74LS74 U108
 
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