Description

Monitor has gone black.

William walked away from RFM while the light self test was on. When I came back it was still active, but the monitor was out. Powering off and on didn’t help. Measured power going to CPU at 120v, 0.32A. Measured power going to monitor at 120v, 0.07A, which seems quite low. We later discovered that the flipper and launch solenoids were out (and presumably the rest, but didn’t test). The root cause is still a mystery.

Media

No media.

Log Entries

Log Entry 1h ·

The high-voltage monitor gives me the willies, so I disconnected the power to the monitor assembly. (First photo.)

The big question for me was whether this was a problem with the PC that generates the video or the monitor itself. I used the oscilloscope to probe the output pins to see if the signal looked right. TLDR, I think it is.

Photo 2 is a pinout I found online and it seems to be correct.

Photo 3 shows how I was testing the outputs.

The rest of the photos show these pins:

  • R
  • G
  • B
  • Vsync
  • Hsync/Hsync+Vsync

The first three definitely behaved information-bearing signals, and they corresponded plausibly with game state changes. The last two definitely look like sync signals. I didn’t compare against specs, so there could be some subtle failure, but my money’s on the monitor.

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Log Entry

CRT monitor is making a constant high pitched noise.
No glow in the neck of the tube.
No picture on the screen even after turning brightness all the way up with the adjustment dials.
No static on the front of the monitor

Log Entry

I remembered that the box with the serial cable was wedged in a tight spot when the playfield was raised. I saw that the metal bracket that pushes the playfield high voltage switch was bent, so I bent it back. Solenoids are now working and the game can be played, but still no video from the monitor.

Maybe next steps are investigating this side of the cabinet for any loose connectors?

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