Re: More Star Wars HV problems, help please?

You really won't be able to get a reading from the filament winding because of
the frequency....your meter won't respond.
Does the filament of the tube light?
You need a HV probe, and as mentioned you must check the grounds along with the
soldering connections on the wintron etc.

Jonathan Stanley wrote:

> OK, I've checked everything else out I can and only found one item
> I'm not sure on:
>
> At the point where the grey Wintron wire attaches to the board I am
> measuring 0 volts. Grey says "filiment hot". What voltage should be
> at this location, and does this prove / disprove the HVT being the
> problem or something on the board?
>
> Thanks everybody!
>
> On Mon, 26 May 2003 13:49:51 +1000, Marc Alexander wrote:
> >
> >I've gotta say it sounds like the sensible thing to send the HVT
> >back to Wintron to be sure.
> >Probably a shorted turn from the HV output back to the B+ out.
> >
> >Looking at the schematics it could be the seperate focus block
> >though as a long shot, so if you can check and/or replace the focus
> >block that
> >would be about the last thing to test.
> >The focus block is the feedback loop from the bottom of the HV
> >winding
> >back to the overvoltage detection circuit, and is also the ground
> >path from
> >the HVT output.
> >You could short the connection between the HVT to the focus block
> >directly to
> >GND as a test, you won't get a picture, but if the HVT still makes
> >noise you'll know it's the HVT.
> >
> >Is the DAG GND connection good from the HV board to the tube and
> >wiring?
> >It's the final grounding path from the HVT and focus block, through
> >the
> >HV overvoltage adjust pot.
> >
> >Have you replaced the W1 jumper with wire?
> >
> >HVT's do fail sometimes regardless of age, there's a lot of high
> >voltage
> >there to break a minor production fault.
> >
> >Do you have a HV probe? When the noise is going are you getting any
> >voltage out of the HVT?
> >
> >Cheers,
> >
> >Marc
> >
> >----- Original Message -----
> >From: "Jonathan Stanley" <jstanley1@cfl.rr.com>
> >To: <vectorlist@synthcom.com>
> >Sent: Monday, May 26, 2003 1:11 PM
> >Subject: Re: VECTOR: More Star Wars HV problems, help please?
> >
> >
> >>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!
> >
> >
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Received on Fri May 30 17:50:21 2003