Re: VECTOR: WG K6100 Troubleshooting

On Thu, 29 Jul 2004, Chris Loggans wrote:

> got a K6100 that came to me with both of the chassis
> mounted low voltage transistors blown (one open, one
> shorted).  I replaced the transistors, installed an
> LV2000 and did a quick check of all other transistors
> and everything appeared to be fine.  I powered it up
> with no signal and it seemed to be running OK.  I
> hooked up the boards, fired up the game and within a
> minute or so, the chassis mounted Y transistors (Q60x)
> were HOT and the low voltage transistors were out
> again.  I replaced all of the transistors again, did a

OK.  First thing first -- you know your input is good - the game board you 
are hooking it to works on another monitor I assume ?

Before they blew again, was there a picture on the screen, spot killer lit, 
etc ? Do you have HV (before those transistors blow) ?

You received this monitor broken -- do you think someone tried to fix it 
before you got it ?   I would go over the board very carefully for anything 
that looks like previous work that might be botched. Example -- someone 
tried to do a cap kit and put parts in the wrong place -- replaced d901 with 
zd901, etc. 

What happens if you power-up the deflection board without the HV 
cage connected ?  

> that was causing me concern is the voltage coming out
> of the U57 (Q603 I think, I don't have my schematics
> handy) going into the base of the 3716.  According to
> the schematics, this should be 0.3v with no signal. 
> I'm getting 0.004 (essentially nothing).  Both of the
> input voltages to Q603 are correct and the U57 has

If it wasn't for the no-voltage here, I would almost think there might be a 
problem in the HV cage that was drawing the extra current.

Oh -- before blowing more transistors, check the fuses to make sure they 
weren't replaced with something bigger, since "They kept blowing." :-)


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Chris Candreva  -- [email protected] -- (914) 967-7816
WestNet Internet Services of Westchester
http://www.westnet.com/