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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: danf2007 on September 06, 2007, 07:30:41 PM
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Hi, I purchased an Amiga 1000 last year and have used it just a few times. It seemed to work just fine before, but now there is a problem getting it to start up properly.
The computer will boot up fine every so often to the screen asking for the Kickstart disk, but most times upon powering on it won't get to that screen now. Instead, I get the light grey screen, then a teal blue colored screen comes up briefly and at the same time the power light flashes four or five times. Then it goes back to the light gray screen and solid power light, and it just keeps repeating this cycle back to the teal blue screen with power light flashing, then the light gray screen comes back. This is an all original Amiga 1000 with the 256K RAM pack installed. I've tried it with and w/o the pack and it still does the same thing.
I have the case open and checked everything for loose chips or connections with the computer unplugged of course. I repair old Macintosh systems often so I know what I'm doing, just new to the Amiga. I removed the three custom chips and cleaned the contacts and reseated. All is very clean, dry and no corrosion or anything inside the case. In fact, the chip contacts looked perfect. There are no loose chips or cables.
Is this a custom chip problem, RAM chip, ROM problem or some other chip? I hope this is just a specific chip that I can replace. Like I said, it will start up fine every once in a while, but most of the time it won't.
Thanks for any help!! Dan
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Hi,
try to desoxydate every chip and sockets.
Then replace each capacitors, they have over 20 years now...
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Light Blue power-on test screen is listed as "Custom Chip(s) fault". I'd check Denise and Paula first, then Agnus.
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Well, I bought something called DeoxIT at Radio Shack and I used it on all the socketed chips(Custom, ROM, CPU) on the main board. I removed each chip and cleaned both the contacts and then the sockets. I checked the entire board carefully and nothing looks bad. I tried starting up again and got it to boot up only twice, all the other times I get the teal blue screen just like before and it doesn't get to the boot sequence.
Then, I read on another site that a turqoise screen indicates a RAM failure in the Kickstart WCS. So, I removed the RAM daughter board and cleaned it completely with the DeoxIT and checked it all over. All looks good. After reinstalling the board I still have the same problem. So, I guess I have a bad RAM chip on this board.
Any further thoughts after this update?
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sorry my only thought is of another a1k passing on :cry:
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If you can't solve it, don't toss it, at least pop it on ebay so some other amiga geek can take a whack at it.
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Wow, you Amiga guys seem to give up pretty easily! :) I won't give up on an original Macintosh 128k system until I fix the problem. This seems like something that can be resolved with the right part, it's not totally DOA.
I'm looking for advice and suggestions from those who know the Amiga better than I do. I haven't even begun to replace any chips yet, so it's still early in the game. You start with the easy stuff and work you're way up.
Does anyone here have any further troubleshooting suggestions based upon the symptoms I describe? I can get replacement custom chips online, or perhaps I need a replacement RAM daughterboard?? Any help is greatly appreciated! Thanks, Dan :-)
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Light blue codes aren't the annoying ones, the Yellow color code is the worst... Try reseating all the socketed chips.. If that doesn't work call your dealer about replacing chips.. I think Yellow and Red were the worst and usually CIA chips (8520s)
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Bad electrolityc caps can do not-so-funny things on a motherboard.
Change all of those little devils (they have the same age of the board, say: >20years!). It's inexpensive and a good precaution, anyway.
Specially change the PSU's caps, they could leak and ruin the PSU, and the motherboard, in the process.
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danf2007 wrote:
Wow, you Amiga guys seem to give up pretty easily! :) I won't give up on an original Macintosh 128k system until I fix the problem. This seems like something that can be resolved with the right part, it's not totally DOA.
I'm looking for advice and suggestions from those who know the Amiga better than I do. I haven't even begun to replace any chips yet, so it's still early in the game. You start with the easy stuff and work you're way up.
Does anyone here have any further troubleshooting suggestions based upon the symptoms I describe? I can get replacement custom chips online, or perhaps I need a replacement RAM daughterboard?? Any help is greatly appreciated! Thanks, Dan :-)
we dont give up easily, my first post wasnt about giving up it was about the possibility of losing another a1k. llwrath told you to sart replacing chips, starting with agnus. you can get custom chips on ebay, in fact the last time i was on ebay there was a full set. most a500 and a2000 chips should work IIRC.
the ram daughter board will be a bit tougher to find though. let us know how you are doing.
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Well, I'm not going to loose this 1000 or just give up on it. I'll get it working correctly eventually. He said to "check" the custom chips, so that is why I checked that all chips were properly seated, then from there cleaned all socketed chips and sockets. There wasn't a mention of actually replacing any of those chips, but perhaps that is the next step.
Today it actually made it to the white screen and the drive started spinning, and then it asked for the Kickstart disk! It would only spin the disk though and then keep repeating this cycle trying to read from the disk and going from a white to gray screen and back, until it eventually went back to the light blue screen just like before! My drive head was fully cleaned and was working just fine prior to all of this so I don't think there is a problem there. If it actually gets to the boot sequence and then won't load from disk what does that indicate(considering the other symptoms involved also)?
Thanks! Dan
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The only reference to a blue screen I can find is for bad custom chips. None of the docs specify if this blue is light, dark, or ????, and this one I have not seen myself - even on my A1000.
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Hi, Here is a link to a site I found that says that a failure mode [color=00ffff]turqoise[/color] screen color on a A1000 indicates a RAM error in the Kickstart WCS.
http://www.nyx.net/~rdavis/AmigaHints2.html#BootColor
The screen I get is that color, a light teal or aqua blue, like a [color=00ffff]turqoise[/color] color.
That site also says in a chart that blue indicates a custom chip error, but I'm guessing that is a more standard medium [color=0000ff]blue[/color] screen color??
So, if that site is accurate I would guess that I have a RAM problem on the A1000 daughterboard, and not a problem with the custom chips. What do you guys think?
Thanks! Dan
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Yeah it could be the WCS (Writeable control Store) daughterboard - that was my first thought. It could also be CIA related - the 8520 chips. Swap those two around and give it a shot.
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If you look on aminet, you should be able to find a hack to replace the WCS daughterboard with a Kickstart ROM. You micht consider that, if you convince yourself the daughterboard is bad.
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I took glitch's advice and swapped the two 8520 chips around just for kicks. Get this... when I switch them I get absolutely no display. The power light comes on but that is all I get. The two 8520 chips have identical part numbers so I should get the exact same results no matter which of the two sockets they are in right? When I swapped them back to their original locations I got the turqoise failure screen again. Just to make sure, I swapped them a second time and got the same results. So, when the 8520 chips are in their original socket location I get the turqoise failure screen, but when I switch them around I get no display at all.
Does this mean that I just need two new 8520's and that will solve my start up problem, or is this perhaps another problem? Where can I get 8520's that are for the A1000?
Thanks so much! Dan
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The 8520s control different things. It's a standard test to swap them and see if the problem changes. Some of those problems can be pretty strange. I had a 1000 with a bad 8520 once.... the TOD counter was screwed up. The clock would run for about 15 seconds, then jump back and repeat... sort of a "Groundhog Day" effect.
You probably only need one chip replaced.
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Blowing the CIA chips (the 8520 or 8520A) is a very common problem regardless of the model involved. They are pin identical on the A1000/A1500/A2000/A500/A3000 and can be even taken out of a junker if you come across one. I'm sure the guys from amigakit.com will chime in any second now... If you in fact need another WCS board just ask around here. I think I might even have one around somewhere.
Good luck getting the old lady going!
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Thanks guys! Today the computer booted up on the first try, read the Kickstart, and the Workbench disks with no problems! I was playing around with stuff on my original Extras disk then the computer just froze, no response from mouse or keyboard, and the screen was just stuck on what I had been doing. So, I did a soft reset (Ctrl plus the Amiga keys) and then it went back to the same old turqoise blue screen just like before and wouldn't get to the Kickstart screen! Any thoughts on why it would just lock up like that? I'm guessing the bad same chip/chips are causing this problem too.
I found a place online to buy 8520 chips for $15 each, so hopefully that will do the trick. I guess I'll buy two just to be sure, although only one is probably bad. It says they are for the A500, A2000, and A3000 but according to you guys they are the same in the A1000 also, so it should work. If I had another Amiga lying around I'd just try the ones from it, but I don't.
If not I may need a WCS RAM daughterboard so thanks for the offer glitch!
Dan
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Any updates for us?