A4000 040 Dead jim?

[MadLensman]

Caps all changed, although to be fair, the originals looked A-ok and there were no signs of leakage except around the barrel battery - (Which I also have changed just in case) - After cap replacement she still booted fine and dandy so no worries
 
What actually occured was a sudden loss of all Fast Ram - just 16m to nothing in milliseconds then when I rebooted to check the RAM she refused to boot up at all!
 
So - now got the board out of the case and bread boarded - Getting heat at Alice and CPU so assuming they're running but no output. Buster is colder than a cold thing in a freezer, and paula, she's a mean b1tch - hot one second cold the next boot so thinking I'm flogging the proverbial dead horse maybe?
 
It's a REV B board and I've got a A1200 accelerator with a removable 040 in it that looks compatible with the same slot on the A4000 CPU card - Presumably it's a simple(ish) matter of change the chip and as long as I'm not too heavy handed this'll tell me if the cpu is fubar? (A1200 should boot using the chip from the A4000 if no boot then dead cpu?)
 
Ta for the offer of the cpu board Spirantho - If I could be sure it wasn't something likely to fry someone else's gear I may have been happier to accept.... lol! :hat:

[spirantho]

Did you try pushing down on the chips when turning it on (especially Paula, if it's erratic)? You might have sit there for about a minute with your thumb on the ceramic while it tries to boot.

[MadLensman]

I think I may be making somke progress - Now have heat at Paula, Alice, The 030 but no heat from Buster at all.
 
On investigation, the RAM slots have obviously gotten warm at some point in their long lives as the plastic retaining clips are missing in some slots, broken in others and have migrated under the motherboard! - This no doubt explains the loss of FAST Ram I experienced before the machine swan dove into her grave.
 
No matter how gentle people seem to be, these damn clips appear to be more and more fragile - Most SIMMS are sitting in the slots fine, and seem to retain ok, but banks 2 & 3 are not clicking into their laid back position properly.
 
Even running with just Chip RAM is proving difficult as Bank 0 doesn't appear to lock properly either.
 
I may be about to give up and move this old girl on as a donor parts machine!

[spirantho]

At least give me a chance to have a crack at it before you divvy it up. A4000 motherboards are quite hard to find (read: bloomin' expensive) these days, and most of the useful parts on it you can get from a much more common A1200....

[MadLensman]

Well, no life whatsoever after leaving her all night with just the chip RAM in - Think the old girl may have been toasted good.
 
A fine inspection with a magnifyer still shows none of the usual capacitor damage and I've used a good PCB cleaner to clean the dust and debris off the board front and rear to make sure that it's not just a "cr4p-out" (Literally) - SIMM in chip ram slot is now a known good working 2mb 70ns chip as recommended, and will run overnight again to see if the dreaded black screen does go away at all, but I'm almost at the end of my rope now - Brace yourself Spirantho - I forsee an A4000 board in your near future my friend! :roflmao:

[MadLensman]

That's it - I give up!
 
(I don't want to, but have run out of time to spend on this particular machine)
 
Anyone who would like a crack at this A4000 is most welcome, free to a good home! - The following are the good bits:
 
Working PSU in apparently good order
Seems to get power to most of the motherboard - Although no output?
4 x 4mb SIMMS Ram + 2mb Chip RAM - all checked and good (Working)
Everything other than the motherboard seems good!
Case in OK condition
Genuine AMIGA branded keyboard etc etc.
 
Will throw in a switch dead commodore monitor which I haven't even had time to look at yet!
 
All free to good home - Collection from Devon UK advised! :roflmao:

[spirantho]

PM sent

[Amiwest]

I was lucky, black screen on my a4000D, reseated the cpu board and it came back.

[MadLensman]

PM replied to.... lol!