SadMac 00000002/0000FFF7 on Classic?

[Schmoburger]

So I just went to boot up my Classic and got the following sad mac error...

00000002

0000FFF7

The first boot produced a bong, then the sad mac appeared, 2nd attempted boot I got no bong and went straight to the sad mac with some video artefacts. 3rd attempt I got no bong, still got the code  and a clean non-artefacted screen.

The machine was working perfectly the last time I used it.

Any ideas?

 

[Schmoburger]

So, It would appear the first line indicates initial memory test fail, however I am not so sure how to decode the second line exactly...

Also, I not on a 4th bootup attempt, where I get the garbled artefacts again, I actually get a slightly different error to the clean screen error. whilst I get the xxF7 bottom line with a non-artefacted screen, with the artefacted screen i get an xxFF

 

[Macdrone]

Might reseat the roms and memory. Caps of course if you have not already.

 

[Schmoburger]

Mmmm I was going to do a precautionary recap soon on the machine anyway even though the machine worked perfectly and seemed in good shape. I will pull the RAM for a start and see if it helps and maybe pull the ROM as well and reseat it and go from there.

 

[Schmoburger]

Well, looks like it was a simple fix. Pulled out the entire RAM expansion module as a unit, pulled the board for a quick visual (no leaking caps), and put it together just leaving the onboard memory and both drives unplugged... it bonged and booted to a flashing floppy icon as normal. Going to now try booting with the card installed and SIMMs removed to isolate the bad RAM.

So, that brings me to the point of, does the Classic require SIMMs to be installed as a pair or may they be installed singularly?

 

[Schmoburger]

Update... I put in the RAM module from my other classic with the AB needing attntion and a pretty sad looking logic board, then went went to boot up again, only to get a garbled checkerboard pattern the same as I got on that Mac but without the vertical oscillations. Unfortunately I got yet another RAM error this time with the board running barebones, so it appears the problem is on the logic board.

Now having got an inkling that the RAM in the other machine was the fault all along, I went on a limb and put that nasty looking old board in the machine I am working on, and surprisingly it actually booted to a blinking floppy straight away, albeit with no bong which I presume is due to bad caps or a corroded contact somewhere (it is a really sad looking board compared to the one that was in the machine)...At that point I plugged the drives back in and this time it booted to the desktop no worries. Then I went on another educated hunch and put the RAM i initially pulled out ( not the checkerboard RAM), and surprise surprise it works as well. SO currently the machine is running next to me with a full compliment of RAM and no issues aside from the lack of sound... this obviously is not a permanant fix, but more a diagnoses of some secondary issues, and also a tangential point of interest, as I was initially just going to harvest that board of I/C's. Now I might clean it, recap it and see if I can get the sound working again after all.

Anyway, back to the original problem of my once good board, I have pulled it out and decided to have a really thorough look for physical damage or corrosion, or any shortsfrom forign matter that I might have missed, and happened to run across this on the underside... Have a look at the trace between Pin 7 of the RAM socket and R13, and Pin 8 to R12, where they run along parallel to the socket.



I cannot be 100% certain, however to me, that looks to be some sort of damage to the circuit trace... possibly resulting in a break or a short to the adjacent trace. Unfortunately , my iPhone is in potato-cam mode due to full memory, so I couldnt get the greatest picture but from what anybody can see, do I look to be on the right track here? Could it be as simple a fix as just running the connection formed by that trace or traces as wire?

 

[Macdrone]

Well if you test continuity with a meter and it's not there and should be just run a wire. I can't tell from the picture.

 

[uniserver]

Hey man that's trying to be rude or anything but before you waste a single second at whatever it is that you're doing there any troubleshooting and All, remove the capacitors wash the board instantly dry the board with an air compressor make sure to take special care under the ICs because Goo likes to hide under ICs, install some fresh capacitors and more than likely you'll be fine . I don't mean to be snippy either but when people say it worked just fine yesterday or at work just fine last week or it work just fine last month so that means it should work fine now ... Especially if you have not changed the capacitors it will work fine one actual moment and then not work the next because that is how it goes when you don't change the capacitors

 

[Macdrone]

I second what uni said, be assured after decades these caps are going bad, even the best caps will dry out and not do the job.

 

[Paralel]

I honestly believe that running old macs with bad caps can lead to permanent damage. I could very well be wrong, but why take the risk?