Re: Tempest WG6100 Blows F700

I've had F600/F700 blow on power-up when a power transistor isn't seated
properly in its socket. When you replace any of those metal-can TO-3
transistors, it's very easy to accidentally short the case (or, less
likely, the base or emitter pin) to the monitor chassis. Use your ohmmeter
to check the resistance between the case of the transistor (the collector)
and the chassis. If you see zero ohms, there's your problem.

When reattaching the transistor socket, I've trained myself to listen for a
"snap" as the mounting lugs on the socket click into the holes on the
chassis. If you don't hear the thing snap into place, there's a good
chance it's not fully seated. Once the socket is in place, try to wiggle
it back and forth and side to side -- if it's mounted correctly, it
shouldn't move at all.

Also, make sure the TO-3 insulators are intact, with no cracks, and that
they actually do isolate the transistor case from the chassis.

And, finally, you can blow fuses if you don't reinsert at least one of the
two screws that fasten the transistor into the socket. The screws are
conductive and form a critical part of the circuit. Once, when I was being
lazy, I didn't put the screws back in because I was "just testing," and I
didn't realize that without them, things go ka-pow.

--
David Shuman
On Thu, Oct 11, 2012 at 3:14 PM, <kspradling@kc.rr.com> wrote:
>
> ---- akswanson@ntelos.net wrote:
> >
> >
> >
> >
> >       F700 is the yoke protection, and it usually means your getting DC
> to the
> > yoke.  It could be one of the output transistors or the MPS
> > U57/U07.
> >
> >
> Thanks...  Have replaced ALL Q70x parts with new.  None of the old parts
> tested bad.  NTE49/50 for Q704/Q703 and PN3569 for Q700-Q702.  And new
> Q705/Q706 parts as well.  It blows with the game board disconnected so I
> suppose the next step is to see if it blows with the X pin removed from the
> connector to see if I have a harness problem.  Or maybe just remove the
> power and see what readings I get on R700.  I should be able to get the X/Y
> display on the scope from R600/R700.
>
> Thanks for the information.
>
> >
> >
> >
> >       > Thanks Jerry,
> >
> >       >
> >
> >       > I don&#39;t think the problem is in the low voltage section
> (100s)
> > of the
> >
> >       > board. Something in the 700s seems to be the problem. If it were
> > blowing
> >
> >       > F100 for F101, that would be the case. It looks like I need to
> start
> > at
> >
> >       > P700 and work my way backwards, pins 3 and 7 control the base for
> > the
> >
> >       > deflection amplifiers so with HV disconnected, I should be able
> > to
> >
> >       > determine which of the +/- amplifiers are being activated. The +
> > side
> >
> >       > looks much simpler...
> >
> >       >
> >
> >       > Kirk S.
> >
> >       > ----- Original Message -----
> >
> >       >
> >
> >       From: jerry madsen
> >
> >       > To: vectorlist@vectorlist.org
> >
> >       > Sent: Wednesday, October 10, 2012 6:43 PM
> >
> >       > Subject: Re: VECTOR: Tempest WG6100 Blows F700
> >
> >       >
> >
> >       >
> >
> >       > Check the 2 biggest Capacitors on the deflection board,meter
> them to
> > see
> >
> >       > if you have a short on one or both,i have same problem before and
> > that
> >
> >       > was the cure,maybe that will be your problem.
> >
> >       > Jerry.
> >
> >       >
> >
> >       >
> >
> >       >
> >
> >       >
> >
> >       From: Kirk Spradling <kspradling@kc.rr.com>
> >
> >       > To: vectorlist@vectorlist.org
> >
> >       > Sent: Wednesday, October 10, 2012 4:38 PM
> >
> >       > Subject: VECTOR: Tempest WG6100 Blows F700
> >
> >       >
> >
> >       >
> >
> >       > I was experiencing random garbage on my Tempest so I pulled the
> > boards
> >
> >       > out, removed the solder from the interboard connectors and
> > resoldered
> >
> >       > them. I put the board back into the machine and F700 blows
> > instantly.
> >
> >       > I have replaced ALL Q70x series including the chassis mounted
> >
> >       > transistors and it still blows F700. I have disconnected the edge
> >
> >       > connectors from the game board and it blows F700. I connected my
> > Oscope
> >
> >       > to the game board X/Y and it displays the game and test screens
> >
> >       > perfectly with the same scale in X and Y. LV2000 installed years
> > ago.
> >
> >       > Transistors all test good and no shorts to chassis. First version
> > of
> >
> >       > the deflection board with no imput protection installed. Spot
> > killer
> >
> >       > lit.
> >
> >       >
> >
> >       > I&#39;m pretty sure that it is related to the game board repair
> > however I am
> >
> >       > at a loss as to what is going on since it blows without the game
> > board.
> >
> >       >
> >
> >       > The 6100 Faq doesn&#39;t mention much about blowing the
> deflection
> > fuses. I
> >
> >       > guess I should start taking some measurements on the deflection
> > board
> >
> >       > itself to see where I am getting the full-on signal. Pull the X
> >
> >       > amplifier connector and check some readings. I guess I had better
> > look
> >
> >       > at the schematic again.
> >
> >       >
> >
> >       > The diodes test ok as well. Guess I will start on the resistors.
> >
> >       >
> >
> >       > Thanks in advance...
> >
> >       >
> >
> >       > Kirk S.
> >
> >       >
> >
> ---------------------------------------------------------------------------
> >
> >       > ** Unsubscribe, subscribe, or view the archives at
> >
> >       > http://www.vectorlist.org
> >
> >       > ** Please direct other questions, comments, or problems to
> >
> >       > chris@westnet.com
> >
> >       >
> >
> >       >
> >
> >       >
> >
>
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