SE/30 with jail bars

V

vtgearhead

Tinkerer
May 1, 2023
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Burlington, VT USA
In an earlier thread I mentioned having replaced the 68030 on my SE/30 with a socket and installing an accelerator. Afterwards I ran it for a week on the bench with no problems. Closed up the case, ran it for another day or two. No problem. Today, this:

The machine is 100% operational aside from the annoying stripes. Does anyone have an inkling of what might be causing the problem?

stripes1.jpg
 
First, I'd recommend changing the title of the post to give people an idea of what you are looking for help with. I saw you post and went to look into my notes to get help, and when I came back, I initially couldn't find you post because the title "Just count on it" didn't provide me context.

Second, I had a similar issue with my SE/30
12_217.jpg.png

My problem turned out to be the the UE8 chip. I replaced and video was fixed:

"2023-02-01 Forum on ml68k indicates could be UE8 chip. I removed, and realized it had some pins rotted out. Waiting to replace."
"2023-03-01 Replaced UE8 chip and video worked properly again

So I would check traces in the area, and if the traces seem good, maybe remove the chip and replace.
 
I hate intermittent problems... Took the machine apart and ran the motherboard on the bench using extension cables. The problem appeared initially. While it was showing the jailbars I poked, prodded, knocked, bent the pcb slightly and used freeze spray in the area of UE8. No effect on the bars, not even a flicker. After a few minutes I walked to the other room to grab the schematic diagram. When I returned, you guessed it, problem gone and nothing I've tried will bring it back. The leads on UE8 definitely had some corrosion on them from the formerly-adjacent SMD cap (replaced years ago). Rather than remove the chip I ran flux down both sides, tinned up the tip on my iron and drag-re-soldered both sides. System is back together for a hot soak, but so far it's fine.

If it pops up again I'll replace the shift-register.
 
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vtgearhead said:
I hate intermittent problems... Took the machine apart and ran the motherboard on the bench using extension cables. The problem appeared initially. While it was showing the jailbars I poked, prodded, knocked, bent the pcb slightly and used freeze spray in the area of UE8. No effect on the bars, not even a flicker. After a few minutes I walked to the other room to grab the schematic diagram. When I returned, you guessed it, problem gone and nothing I've tried will bring it back. The leads on UE8 definitely had some corrosion on them from the formerly-adjacent SMD cap (replaced years ago). Rather than remove the chip I ran flux down both sides, tinned up the tip on my iron and drag-re-soldered both sides. System is back together for a hot soak, but so far it's fine.

If it pops up again I'll replace the shift-register.
Click to expand...
Yeah, my chip didn't look too bad but when I removed it, the legs fell off at the base, making me think the corrosion was worse inside than what I could see. The good news is they are cheap and easily available.
 
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