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| Some old rusty SE's to fix |
Posted by: falen5 on 2024-10-05 16:26:07
Going through some old machines from the attic that dont work
Took down and SE and have 2 logic boards
recapped the entire analog and PSU - have good voltages
ones board is dead - black screen
the others gives a display with the flashing floppy prompt - no sound
will an SE logic board work with no math co-prosessor - i see some of the pins on the dead board are really corroded |
Posted by: Nixontheknight on 2024-10-05 17:23:14
no reason why it shouldn't work without a math coprocessor, I'd check the voltages, and if everything's good there, open it and look for capacitor leakage and battery leakage |
Posted by: ymk on 2024-10-05 18:52:53
SE doesn't have an FPU. If you're talking about the BBU, it needs to be installed to boot. |
Posted by: falen5 on 2024-10-06 12:09:42
SE doesn't have an FPU. If you're talking about the BBU, it needs to be installed to boot. Took it out on the board that works and it wouldnt boot without that chip either
pins within the socket are badly corroded - tried cleaning with iso , no good
gave gentle rubbing with fine sand paper , went straight down to the copper from the corrosion
i have acetone - think ill try it with a tooth brush on the socket and the chip itself
think i can solder 2 pins on my meter probes and test for connectivity between chip legs and socket
re the rest of the board - a cap fell off as i was handleing the board - i noticed various blobs of solder on other caps - will give everything a good clean - the more i look the worse it is getting
looks like the battery leaked its destruction , how it got in the BBU is anyones guess
do those roms look OK ? |
Posted by: dv- on 2024-10-06 13:06:42
They look ok but I’d still take any socketed stuff out, spray contact cleaner around, make sure there’s no corrosion in the sockets, etc. Shouldn’t take long. |
Posted by: falen5 on 2024-10-06 13:24:56
Got in there with vinegar and a tooth brush first
then washing the whole board with a mild soap - the dirt that came off it !!
a few of the pins in the BBU socket were 'back a bit' further than the other pins - carefully used pin to bring them forward , level with the other pins
looking a whole lot better
have to reinstall the cap that fell off - dry it all off with hot air and fire it up |
Posted by: falen5 on 2024-10-06 19:45:32
Got the cap that fell off soldered back in
fired it up
Success
Had to spend some more time cleaning those pins within the BBU socket - fitted it and removed it a few times
Machine looks good
Now I have the other board - it works but no sound |
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