I know this is not a big help but if you have access to a "Ring" tester for
flybacks then you can use that to see if the transformer is OK.
Caution - shameless plug below!
It just so happens that I sell those, suitable for all monitors including
Vector flybacks/transformers, for around $35US in kit form. For more info
go to:
www.flippers.com/fbt-main.html and check it out. Someone could buy one and
share it amongst those that need it every now and then...we find it handy
to keep on the bench for testing suspect HVs (along with the ESR Capacitor
meter kit www.flippers.com/esrktmtr.html )
Well, I warned you. They are very handy for testing parts in circuit, I use
them for fixing Vector monitors and regular ones on a regular basis...
John :-#)#
At 11:11 PM 25/05/2003 -0400, Jonathan Stanley wrote:
>Recap: No display - no high voltage - recently rebuilt HV board and
>installed new Wintron HVT. Worked fine for a month. When it stopped
>working I could briefly hear a strange noise. There was no smoke or
>smell.
>
>OK, here is the latest:
>
>Test results: My BU406D is fine. All my resistors are fine.
>Q1/3/4/5 are fine. My +30/-30 and +24/-24 are fine. VR1/2 are fine.
>
>But I have no display, and the red overvoltage LED comes on. I read
>that I might be getting false readings since the overvoltage was not
>allowing my tests to be under load, so I pulled one leg of CR1 by R7
>(DANGER - XRAYS!) to run my tests since I had tried everything else I
>could think of...
>
>THE NOISE IS BACK! After pulling CR1 the noise is back big time! I
>am 99% sure it is coming from the Wintron HVT. It sounds like
>somebody slowly shutting a squeaky door in between 2 power lines
>(lots of static and popping at changing frequencies). With the
>overvoltage disabled, it will make noise for as long as I dare leave
>it on. I checked my voltages and they are still good. I seem to
>have no high voltage even with the overvoltage disabled.
>
>There is no smoke, no smell, and the HVT is cold to the touch.
>
>Sound like a bad HVT? It is practically brand new. Has anybody had
>any other part of the board make that sound? I really don't want to
>start putting my ear up to parts on the board. It sure seems like
>the HVT as near as I can tell.
>
>I'd rather not have to build a LOPT tester. Would somebody consider
>renting me one? Or, I might just send back the HVT to Wintron and
>let them test it.
>
>Any advice appreciated!
>
>
>
>
>On Sun, 11 May 2003 18:41:28 -0400 (EDT), Christopher X. Candreva
>wrote:
> >On Sun, 11 May 2003, Jonathan Stanley wrote:
> >
> >>and had set it to exactly +180V. I haven't actually pulled the
> >>BU406D yet, but I did make sure the collector is ohming out with
> >>the
> >>heatsink and that the two legs have continuity down the traces.
> >
> >One thing I've learned, if ANYTHING goes bad, the BU will blow. It
> >is almost
> >certainly blown -- pull and check it. While you are at it check C8
> >(or
> >whatever the high-voltage poly-p cap is). If your meter doesn't have
> >a cap
> >checker, it's a god investment (as is the LOPT checker)
> >
> >When you buy BU406D's get at least a dozen.
> >
> >
> >==========================================================
> >Chris Candreva -- chris@westnet.com -- (914) 967-7816
> >WestNet Internet Services of Westchester
> >http://www.westnet.com/
> >---------------------------------------------------------------------
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>
>
>
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Received on Sun May 25 22:24:54 2003
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