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sharman2k
July 20th, 2009, 03:20 PM
Hey ... I need help, before true madness sets in!

I have been restoring some old Mac hardware to further build my collection (details of which to follow in another post) and got my grubby mitts on a Mac SE/30. At the time of purchase, it had a slight fault.

The Mac booted up and displayed 8 horizontal black and white bars in the first 1/3 of the base of the screen. Then, in the second 1/3, a smiley Mac. And finally, in the top 1/3, another smiley Mac! :confused: One I have never seen before - it appeared as the screen was ghosting the image three times. It booted to desktop, just was difficult to navigate as it only showed the screen three times.

This, in my experience, usually means memory or SIMM-ROM faults; often cured by a little cleaning. The case was extremely yellow and dirty and it was my intention to remove the yellowing, clean it up and make that look all pretty. As part of this, I needed to remove the inside of the machine to complete the de-yellowing process. In doing so, I decided I would clean up all the inside components at that time.

All put back together, and now I am haunted by a fully screen on horizontal black and white bars, 8-10 pixels high. The Mac's drive spins up, but then slows, there is no 'bong' and a PRAM zap has not helped. I stripped it back down, checked I had connected everything back together right (after extensive labeling on the dismantle) and all seems well. Does anyone have any ideas? I'm not so familiar with the Compact Mac's; this fault is something I have never come accross. As I have display and spinning drive I have ruled out the power supply, analog board and flyback transformer.

Please help if you can, before I go insane!
:roll:

tezza
July 20th, 2009, 03:25 PM
I DID go mad trying to repair a Mac SE (http://www.classic-computers.org.nz/blog/2009-04-23-Mac-SE-resurrection-bridge-too-far.htm)!!

Have you seen the information here?
http://www.biwa.ne.jp/~shamada/fullmac/repairEng.html

If not, hopefully it will help. It does mention horizontal lines.

Tez

sharman2k
July 21st, 2009, 02:29 PM
Tez

Thanks for the info; it looks exactly the fault so I'll give that a go.

I just need to find an old logic board to practice on in the first instance - I'm not known for a steady hand!

Jon

channelmaniac
July 21st, 2009, 10:35 PM
Replace the filter network first. It was a common problem back in the day when I used to do component level repairs on those old beasts.

Those old Macs had some of THE MOST stubborn solder on them. I swear they were using silver in their solder years ahead of RoHS. The easiest way to desolder things from those boards is to add more solder first before trying to remove any.

RJ