Mac 128k Sad mac at startup

[Moofo]

Hi.

I took my Mac 128k original out of storage. It nows shows sevral artifacts in the screen (Lines) and I get the sad mac immediately after the startup sound.

Since the case is perfect and the scren is pristine (Phosphor is still blue). I would really like some tips on how to fix it.

It's really a mystery why it doen't work anymore. It was stored for like 5 years and was working when I took it there...

Sigh...

I have a huge mac collection... Which I'm going to spend some time on soon.

http://www.moofo.com/passions/vintage-computers/

 

[slomacuser]

computers were made to work not to be stored, you should run them at least every six months, because even a year could make your computer not working. I lost many components like that (scsi drives, Apple II PSU, etc) becaues of dry condesators, leak battery and so on ...

 

[equill]

Electronics do not usually fail during disuse, but mechanicals can, as slomacuser writes. What boot floppy did you use? For a floppy-driven Mac the presence and good condition of a floppy disk at startup is truly vital, if only to ascertain that the FDD still works.

What was the error code under the Sad Mac? What is the condition of the backup battery, meaning has it broken down and gooped onto the logic board? Five years without battery-sparing is a long time, and such batteries are awkward, but not impossible, to get hold of nowadays.

de

 

[Moofo]

Hi.

I looked closely at the Logic Board tonight and it is in good physical condition. No leaked capacitor. I removed the battery and still no go.

The code under the sad mac is 040003.

According to This page it means that the MOD3 Memory test failed on chip 3...

I'm not too keen to replace the chip since the board is really neat and the memory chips have an Apple Logo on them...

 

[equill]

Atmospheric corrosion of the older (Macintosh to Plus) logic boards is a real possibility, as also are cold solder joints. Try an inspection with a good magnifier, looking especially for unlacquered traces with orange or green discolouration, and dull or cracked solder joints. Begin at the system-identified RAM chip, but include the whole board. The board can be either spot-repaired, washed and re-lacquered, or given some combination of these, especially if it is a primal 128K that you have and wish to retain in (relatively) pristine state.

de

 

[tomlee59]

To equill's excellent suggestions I would add that carefully removing and then re-inserting the ROMs may also be worthwhile. Apple did not choose the highest-quality sockets, and it is very easy for a thin film of oxide to form over time. Even though the error code says that it's a RAM problem, the self-test is very crude, and many things other than a RAM problem can be misinterpreted as a RAM error.

 

[Moofo]

I have artifacts in the screen as well. I really think one memory chip is bad. I will toy on that this weekend.

I will first try the rom thing, then I will just heat the solder on the memory chips.

Thanks for the advices. I will post results here.

 

[Mac128]

Yeah, see I don't think that's what the error code means. What exactly is "chip 3"? Looking at both the chart on that site (and others) and Larry Pina's book, RAM chips are identified by grid: rows F & G, 5-12. You'll note that there is no "0003" on that table.

The fact that you have lines on your display sounds more like an analogue board problem where a leaky capacitor could cause all kinds of problems. And from what I know about them, they can simply start leaking from age alone or from a warm storage area (remember if it was in a box then it had zero airflow).

The thing that bothers me, is why would a RAM chip just go bad sitting there for 5 years? It is far more likely there is a problem on the analogue board. Of all the old Macs I've ever gotten, both dead and eventually failed, none of the problems have involved the logic board.

I would definitely give your analogue board the once over before I started tinkering with the logic board too much or taking a soldering iron to the RAM. In fact, looking at your collection posted on your website, I would swap logic boards with one of your working 512K Macs or Plus ... they are all interchangeable for testing purposes. If the 128K board works with another working analogue board and another logic board exhibits the same or different symptoms in your 128K then you know for sure.

 

[Kallikak]

Does the RAM test stop at the first failure? Or could 0003 mean the test failed for both F5 and F6? I have no idea. Alternatively, is the number being altered by one of your screen artifacts?

 

[MultiFinder]

Actually, from my experience, reseat the ROMs first. It takes about 30 seconds and can save you a lot of headaches. My Classic has had the same issue. The ROM contacts had oxidized just a wee bit. It would show the blinking floppy disk but with alot of garbage and screen artifacts on the screen. So, the ROM can be causing that. I've also gotten the Sad Mac from it due to that.

Try reseating the ROMs.

 

[Moofo]

I know I can interchange the board with one of my 512k, however, many machines of my collection are stashed in my grandmother's basement in my hometown.

I'm taking them back to montreal as I get more storage here in montreal.

As for the machine: I got it from an old lady. I doubt it was used much because the Tour disk was still in the drive when I got it.

I have several machines twice. If you guys are nice enough, we can setup trades or for some items, giveaway.

I also have many bins of parts, memorablia, books and the like.

PS.: I stumbled on an old MacRecorder at work today !

 

[Moofo]

Hi.

Just to follow up...

I tried to reseat the Roms, no success: Still the same artifacts on the screen.

I guess one memory chip is really bad... :-(

 

[equill]

... According to This page it means that the MOD3 Memory test failed on chip 3 ...

That page is almost completely verbatim from MacWEEK Upgrading and Repairing Your Mac 1995, but perhaps both drew on a common source, even if they have no unanimity about which is the class code and which is the subcode. Did you note that when you get the Sad Mac is as important as that you get it? In other words, immediate Sad Mac may be hardware-related, and Sad Mac supervening Happy Mac, software-related.

Given the critical nature (and failure-proneness, especially in 23-year-old examples) of floppy disks to floppy-driven Macs, did you try an alternative boot floppy? Even if board failure is a possibility, it may be traces associated with a RAM chip, and not the chip itself, that have failed. Hence the need for examination with a glass before you pinch your nose and jump overboard (no pun intended).

de

 

[Moofo]

Even with no floppy drive connected, I end up with the same result.

I know the sound of the floppy, and I can swear it'S not accessing it.

 

[Moofo]

It'S like, timing wise:

Bong-Grey screen for less than half a sec, sad mac.

The grey screen has artifacts

 

[Mac128]

The source is Apple (which is copied on sites widely around the net) and unless someone can explain it better, I can find nothing here that indicates your specific error code is specifically a RAM chip. In fact everything in the document indicates it is NOT a RAM chip problem.

http://docs.info.apple.com/article.html?artnum=7748

The advice given here is to try numerous other options before you go at your logicboard with a soldering iron which can cause more problems than not if you accidentally overheat a chip.

Without a floppy of any kind inserted, does it do the same thing?

If so, wait until you can stick your logicboard into another Mac before you do anything. Without going into detail, which I don't have time to reference, there are numerous "random" error codes, which I believe yours falls into the category of, that are caused by failures on the analogue board, which considering the storage history is the most likely culprit based on my own experience and everything I've read.

Whatever you decide, please let us know, but it would be unfortunate to have to start another "mourn the loss of a 128K" thread!

 

[aftermac]

Whatever you decide, please let us know, but it would be unfortunate to have to start another "mourn the loss of a 128K" thread!

I'll second that.

 

[Kallikak]

The class code indicates a RAM test write failure, but the chip identification code does not indicate chip 3. That's an error of interpretation. The chip identification codes are bit based, so the values are 0001, 0002, 0004, 0008 etc. So unless 0003 means 0001 + 0002 failed (which is unlikely I think in such a simple RAM test) it instead seems to indicate an alternative problem, or a side-effect of your screen problems. But remember that the screen is memory mapped, so screen artifacts could also indicate bad RAM.

Edit: actually, after searching a bit I have seen some reference to multiple failures being reported in the chip identification code, so perhaps this is indeed indicating F5 and F6 both failed the write test. But nevertheless I concur with Mac128 that this does not necessarily imply chip failure, and it is worth investigating alternative and easier to repair causes as far as possible first.

 

[Mac128]

yes you are right Kallikak, Larry Pina's book confirms that the errors are additive. This means he MAY have a problem with both chips at F5 & F6.

This may also be the computer expressing some other unrelated problem. The only reason I am still suspect is that I have always felt the RAM chips are pretty hardy in these old Macs and I can't for the life of me understand why two chips would just fail for no reason sitting in a box for 5 years, particularly in the absence of any physical evidence, like a dead bug, corrosion, or conductive material leaked on the logicboard.

However, one other thing to consider is that some part of the logicboard is making contact with the RF coating on the inside of the case. The 512K fixed that problem with a little rubber foot in the middle of the logicboard to keep that from happing and later models had a complete case bottom liner as well, rather than just the small socket RF shield of the originals.

With that in mind, have you tried starting the Mac without the rear case-bucket attached, sitting on a level non-conductive surface? That would certainly rule out that possibility.