Mac Classic Sad Mac Error 0000 000E / 0000 000F

[kennelman]

I have a (was nice) Mac classic that was working until recently. Came up with the above error code one morning. The logic board did show a few leaky caps and a dead battery, so cleaned it as carefully and aggressively of corrosion as I dared, I recapped it carefully, and put in a new battery.  Unfortunately, still the same error - I was disappointed there.

It has a RAM riser board that I removed - same error though. Took the ROM SIMM out, cleaned it, put it back in -- no fix there. I've cleaned with 100% isopropyl alcohol until the board looks new, and looking carefully over the logic board, around the RAM in particular, I don't see any visible troubles. I tried heating the individual RAM chips with my rework setup at 100C - desperate, I know - but his did nothing. Same error.

The web says

$000E Failed Data Bus test. The Z field indicated the bad bit(s) as a 32-bit mask for bits 0-31. This may indicate either a bad SIMM or data bus failure.
Does the 0000 / 000F in the Z field steer anyone to where to look?

I'm guessing it's down to a dead RAM chip ? Although WHY it would fail one morning I don't know. Gamma rays, I guess.

The RAM on this motherboard is soldered on - but there is a riser board with other RAM. Can I remove / desolder the motherboard RAM and expect it to work?

Appreciate any advice from those with experience.

 

[techknight]

a bad RAM IC, or more likely, a rotten broken trace from the cap goo. VERY common when the bad caps sit there too long. 

 

[kennelman]

Good advice. I'll inspect the traces more carefully and hopefully find a clue there.

If it's a RAM chip, by the 000F I'd guess it's on one end of the bank of chips or the other, and not one of the middle ones. I wonder if you can even buy these RAM chips any more. Doubt it. Probably have to find another dead Classic and loot it.

If (when, more likely) it all fails on me, is this kind of board (Mac Classic, 68K) something you work on?

 

[kennelman]

Hmmm. No luck so far. Dishwasher scrub followed by tanning session at 170F in the oven for 10 minutes sure made it look nice, but still same error. Tried the ROM chip in a few different configurations -- that wasn't it. I had it in right all along. I can spot any traces to bridge over, and my ohmmeter seems to find all the somewhat more dodgy looking traces near the caps are still conducting normally, so they seem intact.

Oddly enough, the TMS44C256DJ-10 RAM chips are still available, and pretty cheap, $13 for 10 of them.  I can't tell from the ebay add if the format is identical - the ones in the add look like socketed ones, -- the ones on the motherboard look like they may be socketed chips with the pins bent under. But what the heck, $13 is nothing. Installing them - if I can do it, never having tried that before - will be a rather bigger project. Could spell the end of this old baby... if I do it, I'll try swapping out the end ones one at a time and see what happens.

Well - what else do I have to do with my time anyway, eh?

 

[Bolle]

Old thread is old but I just had a 000E/0001 Sad Mac that would not go away on my Classic when playing around with my Quik30 accelerator.

Turned out I did some damage when changing RAM on the accelerator. One of the RAM slots of the accelerator sits just above this area right here - seems I scratched off the resistive layer on the resistor with the through hole legs of the RAM slots. That must be why I found that sandwich design for attaching an accelerator somewhat sketchy to begin with



See that tiny little white spot on R50? It measures open and sits in between one of the ROM pins and pin #11 on UI1.

I put in a new 22Ohm resistor and the Mac came back to life.

 

[joethezombie]

Very nice! Good eye finding that tiny spot!