Amiga 1000 start up problems

[danf2007]

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

[danf2007]

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?
 

[danf2007]

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 :-)

[danf2007]

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

[danf2007]

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  

[danf2007]

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

[danf2007]

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