I am restoring an SE/30 and had a booting logic board and functional display. Work to date includes logic board recap and cleanup, replaced UE8 chip, removed and cleaned and resoldered ASC chip, troubleshooting SCSI—everything with overall successful outcomes. However, I came to the conclusion that I needed to finally recap the analog board and PSU, so that is what I did.
The process was straightforward, but as the title indicates, the first boot is showing me a black screen with white line:
When I turn on the computer, I get the chime, and although no drive is attached at the moment, with blueSCSI connected internally, it starts up fine using term power, and 5 flashes (no SD card inserted at the moment). I am confident that PSU recap is fine (unless someone reads this and says otherwise) and I have tested it with a multi-meter. Showing 5.29v (tuned to that) and just over 12v, so feeling good about the PSU.
The Scrolls suggest this problem is a failing horizontal scan circuit which makes sense. I definitely don’t hear the high frequency from the CRT the way it used to work pre-anaolog-recap. Possible solutions point to an issue with R19 resistor, desoldering L3 linearity coil and using fresh solder there, or a problem with C15.
I removed and tested R19 and it checks out. Not burned. I think it is a 220 ohm resistor. Anyway, it meters fine with correct resistance. I desoldered L3 and resoldered. Finally, checked C15–this is the non-polar film cap that replaced an axial original that was installed on its end. Since everything was working before the recap, I tried putting the old C15 back into position. No change. It still does this same thing. I double-checked all of my other capacitor replacements to make sure they are not soldered backwards etc., and everything looks OK to me.
Now I am open to suggestions. I have just taken a working mac and turned it into this in an attempt to do preventive recapping maintenance. I am not beyond thinking there is a bad solder joint, or a short somewhere, but I have gone over everything and do not see it. I am hoping there is a something I can test with my cheap meter, or a part I can swap back to original to do tests. Thoughts? We can do this! Right?
The process was straightforward, but as the title indicates, the first boot is showing me a black screen with white line:
When I turn on the computer, I get the chime, and although no drive is attached at the moment, with blueSCSI connected internally, it starts up fine using term power, and 5 flashes (no SD card inserted at the moment). I am confident that PSU recap is fine (unless someone reads this and says otherwise) and I have tested it with a multi-meter. Showing 5.29v (tuned to that) and just over 12v, so feeling good about the PSU.
The Scrolls suggest this problem is a failing horizontal scan circuit which makes sense. I definitely don’t hear the high frequency from the CRT the way it used to work pre-anaolog-recap. Possible solutions point to an issue with R19 resistor, desoldering L3 linearity coil and using fresh solder there, or a problem with C15.
I removed and tested R19 and it checks out. Not burned. I think it is a 220 ohm resistor. Anyway, it meters fine with correct resistance. I desoldered L3 and resoldered. Finally, checked C15–this is the non-polar film cap that replaced an axial original that was installed on its end. Since everything was working before the recap, I tried putting the old C15 back into position. No change. It still does this same thing. I double-checked all of my other capacitor replacements to make sure they are not soldered backwards etc., and everything looks OK to me.
Now I am open to suggestions. I have just taken a working mac and turned it into this in an attempt to do preventive recapping maintenance. I am not beyond thinking there is a bad solder joint, or a short somewhere, but I have gone over everything and do not see it. I am hoping there is a something I can test with my cheap meter, or a part I can swap back to original to do tests. Thoughts? We can do this! Right?
Last edited:
