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codepoet

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  1. Just to close the loop, this was ultimately resolved with a New Old Stock logic board. Someday I'll completely re-cap the original board, just to see if that fixes the problem. NextStation now running great with an external SCSI CD-ROM and an internal SCSI2SD upgrade.
  2. Was able to rule out the monitor using a very hacky hack to get some signal directly to a separate VGA. I didn't know how to deal with the grayscale, so I just sent it to green -- and you can see the same pattern shown. So its something on the logic board. I guess I'll proceed with ordering some caps, and see if that fixes anything (but I doubt it)
  3. Thanks, cross-posted there. There doesn't seem to be nearly as much experience/expertise on Steve Jobs' "other" computers, so I'm casting as wide a net as I can for help!
  4. Picked up a NeXTSTation with matching monitor, keyboard and mouse this weekend -- only $250 complete. Seller reported that it worked last time he used it but that it was showing "diagonal lines" when he tested before the sale. I got it home, checked the logic board and clock battery, then fired it up. This is what I got. Image is stationary and stable...just useless. Someone in a FB group suggested RAM, so I cleaned it up with contact cleaner and re-seated half (a full set of 4), then tried the other half. I noticed some white gunk around the RAM slots, but no obvious cap leakage.
  5. The connector on the analog board is gone -- solder points cleaned bare. I think that's the female end? The end on the wires is still there, just nothing to plug into!
  6. There's a lot of conflicting advice online about discharging -- everything from "don't do it" to "do it or you'll die." I have a copy of Dead Mac Scrolls, but not Pina's full guide. I went middle-of-the-road and set up my discharging kit, but didn't include the resistor -- since many forums suggested any arc would just hop over any resistance. I've probably used this setup 2 dozen times without issue: I only discharge if I'm going to be working near the high voltage gear...which is most of the time, since that's where most problems seem to be. On this occasion, the discharge was fairly sh
  7. Replace the chip shown in this picture. Also see my similar, but worse, situation which was resolved thanks to the above advice from a kind stranger on Facebook:
  8. This was caused by damaged to a chip on the analog board, caused by discharging the CRT to the frame. My discharge cable did not include a resistor, because I read somewhere they wouldn't work. Turns out leaving it out is a bad idea. The damaged chip was a Motorola SN74LS38NDS, which I replaced with the same number but from a different brand, from a spare Plus that was more dead. The picture is now sharp and clear, without any lines. If an expert is someone who has made all the mistakes, I'm well on my way to becoming an expert :-)
  9. Thanks for responding, I concur that all the caps look good. The video problem looks like an extreme version of this guy's SE issues, except he gets a faded picture, and I get none. I replaced the logic board, to rule out anything on that side, and got the same result. Its got to be something on the analog board...
  10. I've acquired a plus that would make a happy boot chime, but show no video -- although occasionally the screen would flicker if the case was smacked. Following Dead Mac Scrolls, I re-flowed the solder on J4, and following a tip found elsewhere online, I re-flowed J1 as well. Now it comes up to only this. Adjusting contrast does not show any other pictures. The Mac boots happily from a FloppyEmu, but the screen doesn't change at all. Reducing voltage dims the image, but does not change it -- nor do any of the other screen adjustments cause an image to be visible. Any advice? I'm obv
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