Recent content by Marconelly

  1. M

    Mac LC 575 Analog Board Recap Guide Photos

    Yes, I see that one 1000uF cap on your board faces the other way. Just put the new one the same way the original one was facing, and you'll have the markings on the board to confirm this 100%. When in doubt, always follow the markings on the board. The photo of my board is before I did any...
  2. M

    Color Classic VGA Woes

    No, I don't have the camera, but I do have an IR thermometer with the laser pointer. I haven't really measured the temperatures, just felt around the board with my finger right after powering the computer off. That's how I found that some components get pretty hot when the computer is shut down...
  3. M

    Color Classic VGA Woes

    I have not replaced any of the diodes or resistors. They all look fine visually and no burn marks around any of them. Only component (other than the capacitors) I replaced was one CNY75GB which had some corrosion on its legs. After that computer worked markedly better. But as soon as I replaced...
  4. M

    Color Classic VGA Woes

    Another interesting find I just had. Now that I've got this board stable (mostly - it still seems to sometimes power off after hours of working fine) I decided to revisit my replacement of the second optoisolator. So originally, after replacing the first optoisolator IC (the one close to the low...
  5. M

    Color Classic VGA Woes

    Not sure if I'm using the right term, but what I mean by sub-brightness is the brightness of a pure black color. Ideally, that should be zero on a CRT, no light should be emitted for black pixels - but when I started using this board, the black color was very visibly bright and green tinted. So...
  6. M

    Mac LC 575 Analog Board Recap Guide Photos

    I needed to recap my LC 575 analog board, and couldn't find a guide for it, so I decided to make one, similar looking to what Branchus Creations has created for the Color Classic analog board. LC 575 AB is very similar in layout and uses very similar capacitors as the Color Classic AB. The...
  7. M

    Color Classic VGA Woes

    Looks like the last piece of the puzzle to get this board fully operational was to increase the picture adjustment R/G/B pots at the back of the board. I used to keep them pretty low to avoid sub-brightness being too high (I originally didn't know the VG2 pot can be used to correct this...
  8. M

    SE/30 with abnormal screen

    Before you do anything else, I'd say just clean all the IC pins with alcohol, using a soft toothbrush. You can do that fairly quickly and at no cost.
  9. M

    Color Classic VGA Woes

    That's where it is, yes. I have found that it leads to J23 jumper lead on the upper side, and measured between there and the metal cage, while the computer was running:
  10. M

    SE/30 with abnormal screen

    If the capacitors or the battery on the logic board have leaked, make sure to check if any traces need repairing. Make sure to also thoroughly clean all IC pins from any capacitor residue using 100% isopropyl alcohol as it can mess up with their operation. You should also most likely just...
  11. M

    iMac G3 speaker replacement success

    I've ordered these, so I'll see how it goes. They were just $5, so I don't mind even if they end up not working: https://www.aliexpress.us/item/1005006899813268.html I felt a bit bad because speakers on my G3 sounded OK until some game that doesn't obey the system volume setting blasted music...
  12. M

    Color Classic VGA Woes

    I found out where TP1 is and what it's connected to, so I can measure it from the top of the board. I'm assuming I would measure between TP1 and say metal shielding that's connected to the ground? Would I be looking for 68.4V DC or AC here? I want to check this because even though the computer...
  13. M

    iMac G3 speaker replacement success

    Looks like these speakers are no longer available on Aliexpress. @mac27 do you have any other suggestion of what to buy? Someone on reddit recommended these as a similarly cheaper replacement, but these don't have the silver port in the middle, so they don't look stock...
  14. M

    Color Classic VGA Woes

    Right now, I've adjusted the PP7 pot, and managed to get the low voltage to be 4.998 / 5.004 V and 11.8. Up from 4.8V / 11.5V - I can confirm with certainty now that PP7 affects both the 5V and 12V. Not sure if it affects anything else, but those two it affects for sure. - Turning PP7 clockwise...
  15. M

    Color Classic VGA Woes

    The things is, it's really haphazard. Today again I've been able to use it for an entire hour, and it still keeps working just fine. Yesterday it wouldn't run for longer than 5 minutes at a time. I keep suspecting that flyback on this board is dying - it's flat surface looks pretty cracked from...