Verified that the game played blind.
11/4/2012 10:10:18 PM
Powered the game up, and verified that the game actually did play blind. I also pulled the board and put it in another Gravitar and it played just fine with a perfect picture. So I was able to rule out the PCB at that time. I also verified all voltages within the cabinet and they were spot on.
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Visual Inspection of the Monitor
11/4/2012 10:11:01 PM
I pulled the monitor out and visually inspected the monitor. I found the following issues: - Fuse F101 blown
- Fuse F600 blown
So it's time to rebuild the monitor.
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Rebuilding the Deflection Board
11/4/2012 10:19:41 PM
To rebuild the deflection board I : - Replaced all Electrolytic Caps (C800, C801, C802, C803, C100, C101)
- Diodes D100, D101, D102, and D103
- Upgraded the Deflection board with the LV2000 kit
- Replaced Fuses F100, F101, and F600
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No B+ on Pin 5 of J900
11/4/2012 10:32:32 PM
After rebuilding the Deflection board, I put the monitor back in the game and fired it up again. Still no static on the screen and when I measured the B+ at pin 5 of J900, I get 0 Volts. So it's time to rebuild the HV section. This can be a pain at times. So here is what I replaced so far: - Caps C902, C901, C914, C909.
- Q900 (Transistor next to Focus control, outside of cage)
- Q905 (Transistor on outside of cage near tube)
I didn't have caps for C905, or C910, so I ordered those along with other parts that I might need to replace (NE555, ZD900, ZD901, etc...)
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Still No B+ or HV
11/4/2012 10:39:17 PM
So I replaced the Flyback. This had zero effect, so it's probably ok. If you can avoid replacing the Fly back, I would recommend it, as it's a major pain in the ass to do. So after doing some more research, I ordered more parts and will be replacing them. I could do tests, but I'm too chicken to stick my hand in the HV section of the monitor while it's turned on, so I'm going with the "replace the most likely part" and see if it fixes it route. Can be a bit more expensive, but less shocking :)
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R920 is Crispy
11/4/2012 11:21:04 PM
Well, the first time through I missed the fact that R920 was a bit crispy. So I pulled it and test it, it measured out at 1.5MOhm instead of 1.5KOhm. The resistor is 1/2W and all I had on hand was, a 1.5KOhm 2W resistor, so I used that. I also replaced C905, C910 and the NE555 at IC901 since I got my parts in. Still no changes. One other thing to note is the Spot Killer light flashes on and off. Hopefully it's not related and I can work on that issue later if I need to.
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DOH!
11/24/2012 9:50:03 AM
Well, I found the reason why I wasn't getting any High Voltage... User error. I missed a connector (P101) when hooking everything back up. If you're not getting voltage from the Deflection board, you're not going to get HV.
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