Re: WG6100 no HV

Check the base of q905 with it running using a scope you should see a square waveform...can't remember what frequency but somewhere around 20khz. Also you should have +28v on pin 1 and -28 on pin 7 not pin 8 of J900.
Can you hear deflection chatter?
  ----- Original Message -----
  From: Pinx
  To: vectorlist@vectorlist.org
  Sent: Sunday, April 01, 2007 1:16 PM
  Subject: VECTOR: WG6100 no HV

  Hello gents,

  i am currently working on my SW again (how many times can this thing die) and it runs a WG6100 which plays blind (No HV) previous problems causing blindness amongst others have been 2 of the diodes on the deflection pcb failing D100 and D101 iirc, i replaced these and the game would work for a while then fail again, so i fitted a LV2000 to the low voltage section and this stopped that problem, whilst i had the monitor out i replaced all the 2N3792 and 2N3716 on the frame and replaced C100 and C102. This then worked fine for a while and then it failed again, same thing game would play blind, so i removed the HV cage and found R903 was duff and so was Q901, i replaced these and the game was fine for a while untill it failed again.

  So after repeated fixes i decided to give up with the "replace whats at fault" route and just shotgun as much as possible, today on the Deflection board (P314) i replaced Q700, Q701, Q702, Q703, Q704 in the X section and Q600, Q601, Q602, Q603, Q604 in the Y section, i also replaced D106 and D107 and R106 and D702, D602 and Also Q800, Q801 Q802. I reflowed all the connector pins and anything else that looked a bit suspect. I fitted a new BIG Blue to the power brick and checked my voltage outputs at the game pcb (all fine) i then removed the HV cage again and on the HV pcb (P329) i replaced the 555 timer at IC901 the caps at C901 and C902 which for some reason were 220uf instead of 100uf, i then replaced C905, C909, C910, C914, R903, R912, R920, R922, R925, ZD901, ZD902, D901, D902, i finished off with replacing the external BU208 (Q906?) and BU409 (Q900?) and again reflowed all connector pins, in fact all pins. Q905 (2N6557) i didnt have in stock so i meter'd it out of circuit and i also meter'd any resistors i didnt have, out of circuit too and they all meter'd ok.
  Replacing so much stuff i know sounds a bit desperate (but i am) as they are all aging components i had nothing to lose. I put it back together and still no HV (using the probe at the anode measured zero) i then checked the B+ voltage pin 5 at P900 i have only 28 volts instead of 180 volts. Pins 1 and 8 both have 28 volts.

  Spot killer led is not on either.

  Anyone got any idea's ?

  TIA

  Pinx

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Received on Sun Apr 1 09:17:04 2007