A4000 goes shape of pear...Help.

[Abou27]

Yesterday, received a Picollo SD64 gfx card, high speed serial port and Commodore "Amber" SD.  Fitted all to my A4000d and intalled Picasso96.  Everything seemed fine.  Browsing web on glorious high res screen, mouse freexes and computer starts to reboot, crashes and reboots, crashes and reboots etc.  During this all drive lights on, seems to load from HD a little.  Power light flashes before reset.  Then the self test red screen once or twice, then yellow.  Switch off and leave overnight.

Switch on in morning and WB loads - yeh!  Lasts 3 seconds and then back to previous cycle.  :-?   Sometimes gets far enough to say that setpatch or makedir failed - but worringly random commands.  Take apart, press ROMs and everything and try in all configurations - same result.  HD lights stays on regardless of whether HD connected.  No red or yellow screens now, though but early startup menu crashes or is corrupt if it appears at all - mostly just gurus. :-(

So, do red screen and no early start-up mean my ROMs are no longer or might this be a display problem?  Or is there a more simple explanation that will take 2 secs to put right?...Please!

Any insights would be most welcome.


Cheers.

A4000D/040 25mhz (Rev 3.1 A3640) Buster 11, 3.1 ROMs and OS3.9

[redrumloa]

@Abou27

Just curious, did you try taking out the recently installed expansion boards to eliminate them being the problem? Maybe one of them are bad, or maybe your power supply aint up to snuff.

[Jose]

Yellow? Hmm, I've recently tested a lot of different memory SIMMS on the A4000 mobo and some gave me a yellow screen after a while. I'd check if anything is loose or badly connected, some stuff on A4000 mobo tends to have that problem after some use, or so I'm told.

[Abou27]

@Red

Yeah, I've tried with boards out - same thing.  I am using the original PSU, though, so that may be a problem.

@Jose

I'll have another look at the memory, cheers.


I also disconnected the hard-drive to see if I could get the Kickstart prompt.  I got it twice.  Once lasted couple of secs.  Second time, screen was corrupted.  That's the concerning bit.

It seems to be when addressing ROM things happen.  There is no way ROMs can be written to, is there?  I mean I can rule out a virus, yeah? (And the award for dumb question goes to...)

[elendil]

The kickstart roms are read-only, yes.

I don't know anything else about your problem, I'm afraid

Sincerely,

-Kenneth Straarup.

[Brian]

Sounds to me like you've fried something. Possibly the PSU but also check the motherboard for burnt traces. Try with a different CPU card to rule that out aswell.

[amigamad]

Could it have been caused by the graphics card or the high speed serial port seeing as it was working before then. is that the graphics card that was on amibench as i remember him saying his machine had died .

It could be the drivers for the graphics card are playing up and causing random reboots or your hard drive could be playing up,  what drivers are you using are they the ones that came with the card as they might be to old for your operating system.what os are you using 3.1 or 3.5 or 3.9. only thing i can think of is its a software problem caused by the graphics card software. :-?

[Brian]

Ehm.. if the cards are removed, the harddrive removed and the early startup meny is still messed up then it's deffinitly not a drivers issue.

[Abou27]

Well, today I am up and running again.  Turns out it was the A3640 board.  Excuse my lack of electronic know-how, but the silver rectangle labelled 50 mhz (oscillator, crystal? I don't know! Laugh as much as you please!) had corrosion around each of its legs on the underside of the board.  I don't know whether it leaked itself or whether electrolyte from somewhere else was attracted to it?  Anyway cleaned up but still no good.  Seems odd coincidence it going on same day I added that extra hardware.


Searched for ages and finally found my 030 card - initially forgot to change MB jumpers but in the end it worked.  So, I now run a slower but nicer looking A4000 system - bizarre.


It's weird how panicky one gets when it all goes wrong - logic goes out the window.  Thanks for all the suggestions.

[Brian]

Good to hear that things are up and running again... now is a good a time as ever to get a real turbo board for the beast. :-)

[Abou27]

Yeah, you're absolutely right.  I will be keeping my eyes peeled.  I am even considering cancelling a proposed holiday in September to finance it :crazy:

[patrik]

@Abou27:

On the rev 3.0 and 3.1 A3640 boards, the C105, C106 & C107 capacitors are powered with reversed polarity which will eventually result in leakage so that could be the source of the corrosion on your board.

Read this page about that problem and what to do about it: Amiga A3640 CPU Board Repair

Good luck!


/Patrik

[Abou27]

@Patrik

Yeah, I was reading about that a couple of days ago.  All of them seem spotless on the board - not a hint of corrosion.  I cleaned the other gunk off but it still doesn't work.  Probably damaged one of the traces or something.  Oh, well!

Eyes peeled for a new card!