Tempest repair

I replaced all of the zener diodes and I have a signal coming out of the 55 timer, but I am still having problems with this HV unit.

The LV 2000 runs without the HV cage plugged in. When I plug in the HV cage, it works for about 10 secs. I have 180v and 19.5kv, then it drops to 10kv or 97v and the V+ light goes out on the LV 2000 board.

The spotkiller LED goes out when the V+ light goes out.
 
It sounds like something may be drawing too much current on the HV board. You'll have to go through and check all components again. Also check to make sure nobody before you put any wrong value parts in there anywhere, as I often see incorrect resistors, etc (e.g., 3.3k instead of 3.3 ohms, etc).

Also, it's possible you may have a bad LV2000. You might want to swap that out, just to make sure that isn't it. We've had a couple of other threads here where that was the issue.
 
I already did that. I purchased an arcadeshop one and now have the same results.
 
This thing has been kicking my ass. I was having trouble with the HV cage, so I depopulated it. I re-installed everything piece by piece. I checked things along the way. I put in a 2sd870 and left the related diode out. It still would not work. I went with the assumption that it was OK and started looking elsewhere.
I was going to take out the LV2000 and install the stock parts when I noticed that I did not solder the +V pin. I soldered that and now I a screen image.
 
I installed the pots to the neckboard and dialed in the monitor.

I now have played my first ever game of Tempest.
 
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