• Hello MLAers! We've re-enabled auto-approval for accounts. If you are still waiting on account approval, please check this thread for more information.

Recent content by AstroFirebird

  1. A

    Calling it with SE/30 Simasimac Board

    It's 527 ohms? That's definitely a problem if the resistance is truly that high. I'd verify pin 8 of UJ6 has a good connection and then verify pin 4 of UE7 is good as well from underneath. If they look good, remove UE7 from the socket and inspect the IC itself along with the socket. if...
  2. A

    Calling it with SE/30 Simasimac Board

    I just fixed a similar issue with the simasimac and happy chime. UJ6 ended up being the culprit, but you definitely have a problem in the video circuit. It's hard to tell what's exactly going on without a logic probe or oscilloscope. Check the continuity between the address lines and UJ6 then...
  3. A

    SE/30 with simasimac and happy chime

    For anyone from the future that may have this problem, UJ6 was the culprit. I replaced it and now have a fully functioning SE/30.
  4. A

    SE/30 with broken CRT

    There’s a replacement CRT available on eBay right now.
  5. A

    SE/30 with simasimac and happy chime

    What would cause no activity on the VIDW line at UE6?
  6. A

    Mac SE/30 Repair Log

    What does the clock signal look like on the probe?
  7. A

    SE/30 with simasimac and happy chime

    Checked with the scope and I do see RAS/CAS go low. Checked VIDW with the scope and it’s always high.
  8. A

    SE/30 with simasimac and happy chime

    Okay. Checked at the VRAMs for VIDW and got the same results. The LED just stays on for RAS, CAS, and DT-OE. So they’re just staying high?
  9. A

    SE/30 with simasimac and happy chime

    I checked VIDW at UE6. It did a flash at startup (dimmer than UJ6 but a flash nonetheless) but afterwards the LED had no activity.
  10. A

    SE/30 with simasimac and happy chime

    Just got a setup exactly like yours. When starting the computer it flashes bright immediately like yours does but after that I can see it flash but it’s extremely faint. So faint that it’s not even lighting up the bulb part and you can just barely see the diode glow.
  11. A

    SE/30 with simasimac and happy chime

    I did it again and made sure I was on triggered mode. There is a little spike that comes down every few second. It’s pulsing something.
  12. A

    SE/30 with simasimac and happy chime

    Thank you so much for the help you’ve provided. Know a good source for one of these ICs?
  13. A

    SE/30 with simasimac and happy chime

    Rechecked and pin 12 has 5 volts. Rechecked the output and it doesn’t pull down.
  14. A

    SE/30 with simasimac and happy chime

    Got continuity for every address line to the processor.
  15. A

    SE/30 with simasimac and happy chime

    Would an oscilloscope work? When I probe pin 8 with that it doesn’t do anything. I see the line stay high but doesn’t ever come back down.
See more
Back
Top