Re: G08 Star Trek with no HV

From: Jeff Klammer <jeffklam_at_comcast.net>
Date: Sun Jan 14 2007 - 19:52:59 EST

Still no luck with this G08 chassis. How much would you charge me to
fix it? I'm hoping to have it running by February 3rd for my kids
birthday party. I think I may have hit my limit on troubleshooting
this one. I saw a chassis on ebay, but it looked overpriced to me.
How much should a working chassis go for?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=016&sspagename=STRK%
3AMEWA%3AIT&viewitem=&item=260074424452&rd=1&rd=1

Thanks,
Jeff Klammer in St. Paul (White Bear Lake)

On Dec 29, 2006, at 6:15 PM, Hans O wrote:

> Yes, no voltage indicates trouble in the X deflection. If you hear
> deflection chatter, you should have enough signal to display
> something on the monitor. Usually the HV unit will still fire up
> with one side of the deflection collapsed.
>
> Some things to check:
> Cold solder joints, especially on the connector, HV transformer
> pins, and T900. Reflow them even if they look good.
> Check for approx. 100v coming out of the little HV board. Measure
> the end of R307 nearest the screw hole.
> Check Q900 (would it still be called the HOT?)
> If so far, so good, then you need to start probing the oscillator
> circuit. May be hard to do without a scope. Start with Pin 9 on the
> IC. If there is no signal at pin 9, then the IC is probably bad.
> Before you chuck it, fix the X section and retest.
>
> If you have oscillation at pin 9, follow the signal through Q901,
> Q902 (on the back of the board), and Q903. Next stop is the end of
> R327 nearest the coil. Last stop is the Collector of Q900 (yellow
> wire, I think).
>
> If you have oscillation up to the HV transformer, 100v feeding it,
> and no cold solder joints, then the last suspect is a bad HV
> transformer (highly unlikely).
>
> Hope this helps.
> Hans O in Chicago
> (If you get totally stumped, I can probably look at it for you.
>
>
> Jeff Klammer wrote:
>> Greetings. I just acquired a Star Trek with no picture on the G08
>> monitor. You can play the game blind and with the back cover off,
>> you can hear vector chatter. The high voltage doesn't seem to be
>> coming on. Here's the voltage readings on the 10 pin to the HV board.
>> 1. Approx +2.4VDC
>> 2. No voltage
>> 3. -9VDC
>> 4. +9VDC
>> 5. GND
>> 6. GND
>> 7. No Voltage
>> 8. 118VDC
>> 9. 10. No Voltage
>> I've done some initial troubleshooting on the G08 chassis
>> (installed Bob Roberts kit), but I don't find any bad parts yet.
>> Can I assume that no voltage on pin 2 means that the problem is in
>> the X part of the deflection board? This is my first time
>> troubleshooting a vector monitor. I'm hoping to find someone in MN
>> with a good Star Trek or G08 vector game so I can narrow down the
>> problem to the Star Trek hardware or the G08.
>> I have read all of the archives and found one similar problem from
>> Dec. 27 of 2005, but it looks like that problem was never solved
>> (or at least never posted a solution). I've posted this on
>> vaps.org also, but so far have not found the solution. I should
>> have my scope up and running in a week or so which may also help
>> troubleshoot.
>> Thanks,
>> Jeff Klammer
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Received on Sun Jan 14 19:53:07 2007

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