G05 HV troubles

hi all..

  I've been fighting with a HV box from hell recently, and i've held off
posting to vectorlist until i was really stuck. I'm at that point now.

Its a G05-802...

  Right now, R901 is smoking up. I'm only getting 7.2kv at the anode,
and the HV adjust pot does not change the hv. I can only have it running
for 10 seconds before R901 really starts to cook off.

  The flyback was actually bad, as the HV was bouncing around from
nothing up to 7kv very erratically before, so i swapped that from a
known-good v2000 hv box. Now i get a steady HV, albeit low and r901
still burning up. (R901 was cooked crispy before the flyback swap anyway)

  I have subsequently swapped _every_ diode and transistors in the box,
and it still acts the same, no improvements. I also changed the
electrolytics, and the HV adjust pot itself (R905).

  Can anyone think of a scenario that would let R901 burn up? any
pointers as to where i should be looking harder?

thanks..

-- 
Andrew Welburn
http://www.andys-arcade.com
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