Re: Hello, and two problems!

On Tue, 24 Aug 1999, Mike Patterson wrote:

> Tempest HV:
>
> At one point I had a working Tempest. Then I got the bright idea to CapKit it
> to try to get rid of some "wiggling" in the lines. I was new to arcade machines
> at the time, and apparently I lost my senses, too, because I managed to put
> a resistor at D901. (causing R912 to smoke)
>
> So, present day. I decide to figure this thing out once and for all. I put the
> original diode back, drop it in and nothing. Not even a part blowing to give
> me a lead. Does anyone have any idea where to start? Is it likely I've blown
> the whole thing?

        "Blown the whole thing" is a terribly non-descriptive term.
Putting a resistor where a diode should be is a bad thing, and could have
blown several parts. If you are unsure about how to test semiconductors,
check out the sci.electronics.repair FAQ at www.repairfaq.org. I believe
the relevant sections are reprinted in the XY Monitor repair FAQ. You
should take a lookj at that also, although it probably won't help you much
with your specific problem. You need to test all your semiconductors,
resistors, and capacitors in the HV unit. I don't know what D901 connects
to off the top of my head, but anything "near" it upstream or downstream
was likely to get taken out. This may or may not be an easy repair, and
there is no definite answer to what is causing your problem, based upon
your description. You have to get down and dirty and test everything on
that board. While you're at it, check your work on your cap. kit
installation.

> -- > Star Wars Deflection: >
> One day, my Y deflection went away. F1 blew, and a resistor smoked. I was
> advised to replace the resistor and the power transistors. Now I don't
> even get a dot on screen.
>
> I have a black HV so I'm not too worried there. If I hook up a scope to
> X OUT and Y OUT, I get the game, so I don't think I'm getting anything
> strange stuff from the mainboard. Again, where do I start?

        Which power transistors did you replace? All of them? That's
where I'd start. Check to make sure that none of the cases of the power
transistors that you replaced are shorting to the heatsink. Is the spot
killer LED on? Are any fuses blowing now?

Joe
Received on Wed Aug 25 09:28:16 1999