Re: More Star Wars HV problems, help please?

Wintron is giving me an RMA - so I am going to send it back and let
them test it. They said it sounds like "internal arcing" and "may
need to be replaced". When I receive it back I will post an update -
hopefully a new HVT will fix it!

Jonathan

On Fri, 30 May 2003 20:48:19 -0500, SteveT wrote:
>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 Sun Jun 1 06:39:39 2003