Hi All, my 1541 works for a while then the head will do the head death rattle thing and I have to power-cycle it to reset it or nothing works. Oh and the drive activity light does the error flash after this happens.

The weird part is that for the first few minutes of use it's working fine - I even removed my Epyx Fastload Cart (havent installed JD yet) but issues still occurs.

Is there a decent trouble shooting guide that covers this issue?
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Some more info - I wonder if it might be heat related as it does get pretty hot at the rear of the drive.
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First thing to do is check the voltages. Are the 5V and 12V there? Measure at the regulator outputs.
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Your drive has shielding? Never seen that. Maybe they did that only in Australia, you know, to keep the drive warm, because it's so cold there

Yes, I would remove anything that impedes circulation of air, since these drives get so hot. This could be the reason why it failed.
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I've been doing some testing and mine didnt have the sheilding I suspected it would so thats ruled out.

I made a heat sink for the 6502 by cutting in half a smallish aluminium heatsink from a graphics card that I had lying around and interestingly it seems to have doubled the amount of time before errors from 5 to 10mins of use.

It also passes the full 1541 performance test if run in the first 10 mins. After that I get the "unit is failing" msg.

So now im wondering if I need a new 6502?

PS, I've also duplicated the issue using both serial ports so im assuming that rules out the 6522's.
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Bump!

anyone with an idea on what is failing here?

I dont want to waste $30 on a 6502 and find it's not the problem!

Btw, mine is the "short board" C= 1541 with the pull down latch (not twist down).
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Does sound a lot like mine as listed above. I never tracked down the problem before accidently dropping a screwdriver on the board while it was running (25 years ago), but it was definitely some sort of heat related issue. I just ran it completely out of the case, with a desk fan blowing over it for a while, and just shut it off when it wasn't needed.

Are any of the chips on it really hot by the time it starts having trouble?
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If you leave the Fast load cart in when the drive errors you can ">" and read the error. that might give some clue as to what is happening. I would tend to agree that heat may be a problem as you say it works fine from a dead stop for a bit.

well strike me pink! I think i've solved the problem without replacing a single chip!!

I had made two heatsinks (split a passive graphics chip sink in 2) and discovered I had a bit of heatsink adhesive tape left so I stuck the other heatsink onto the 6522 used as a motor-controller (UC2) and what do you know, now runs sweet as!

I've been torturing the crap out of it for the last 33mins by running the 1541 performance test on it continuously (managed 8 runs) and not a single error!!! Frankly I got sick of running the test after that long but boy am I pleased to have fixed it!!!

Oh well, looks like I have a spare 6502 and 6522 should I ever need them!

EDIT: Doh, ran 1 more test (#9) and it finally failed, at least it looks like I've narrowed it down to UC2!
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