I need some help repairing my SE/30 Board

[RCMediaAndTech]

Hello, 

My Macintosh SE/30 motherboard has been having issues since I received the computer in mid July. First of all, it used to turn on and do the simasimac, and death chimes but then I sent it out to MacCaps, and he tried to repair to no avail. It did the same thing when I got it back, so I tried washing the board in 5% White vinegar, but that didn't do anything. Any suggestions? Thanks! 

-Ryan 

 

[Crutch]

Did MacCaps actually recap the board for you?  If so great, but you may still have leaked electrolyte on the board.  I don’t think 5% white vinegar would do much (smells nice though in my opinion, and kills germs!), I would bathe it in 90% isopropyl alcohol and scrub it down with a toothbrush.  Let it dry for a day, try again.  Try swapping out both the RAM and ROM SIMMs if possible (RAM SIMMs are available cheap on eBay and elsewhere ... ROM might take a bit more patience to find one.). If none of that works your leaked caps probably damaged a trace or via and you might have to identify and repair it, or one of the ICs on the board might be bad, which I lack the skills to diagnose but someone else here can probably help with!

 

[bibilit]

I have repaired quite a few of those boards, first thing i do is clean the board.

I remove the capacitors and clean again the board locally, so in my opinion this has already been done.

Also, probably a swap test has been done with ram and rom to try troubleshooting the board.

I can be wrong but the death chimes means part of the boot process is working, any fault code is present when the death chimes are heard ?

And yes, Crutch is probably right, probably an IC or broken trace somewhere.

Also IIRC the 74F258 chips (near the Rom slot) can do that.

 

[RCMediaAndTech]

The thing is, the board doesn't do the death chimes anymore when powered on. What should I do?

 

[Crutch]

Oh sorry, what does it do now exactly then when you flip the switch?

 

[RCMediaAndTech]

It boots to the horizontal lines. I tried cleaningthe board with isopropyl alcohol, but it didn't work either.

 

[Crutch]

Sounds like (1) you have bad ROM or it can’t see the ROM (try swapping the ROM as a couple of us have suggested), or (2) another component has failed. One thing to try is see if your symptoms are described in The Dead Mac Scrolls - the PDF is available online if you google it. 

 

[RCMediaAndTech]

I have 2 ROMs, but none of them seem to work, as there are no chimes of death anymore. I checked The Dead Mac Scrolls and I couldn't find anything on the Simasimac on the SE/30. Anyways, I lack the expertise to repair this board, and I think I might need someone else to help me repair this motherboard. Either that or I would gladly buy a SE/30 if anyone has any. Thanks!