Re: SW monitor prob...

OK, I dont believe you have a HV problem but a XY drive problem. To me
if it was blooming from HV going low you would loose focus. I would
check the XY outputs and see if there is a bad connection on the edge
connector such as the ground. Also measure the voltages on the board
(game board)for the +/-15 VDC and the XY outputs. I guess it could still
be the monitor but more than likely something on the deflection board
not the HV. I would also measure the input voltage AC to monitor and the
DC voltage of the deflection regulators, I dont remember what it is,
maybe +/45 VDC or something, if that was amuck could cause your problem.

Thad

Pinx wrote:

> It is in focus,
> just a really large image so some of the image is off the screen....
>
>
> Pinx
>
> ----- Original Message ----- From: "Thad Seeberger" <maddthad@jlab.org>
> To: <vectorlist@vectorlist.org>
> Sent: Wednesday, April 06, 2005 9:15 PM
> Subject: Re: VECTOR: SW monitor prob...
>
>
>> Is the image focused? if its focused (DURING BLOOM) you have XY drive
>> problem. Check the focus block you could have something leaky make
>> sure there is no corona. When measuring the HV is it ok while
>> blooming (loaded) or with no drive. If its fluctuating there is a
>> problem with the regulator. If its bllooming because of HV drop you
>> will loose focus also since the focus is just a divider of the HV.
>> Make sure there is no DC offset on XY input. I havent been following
>> this thread so you might have already checked but I cant think of
>> what else would make it bloom other than a CRT with low emision, is
>> the heater got 6.3V on it? and all the connections good on the socket
>> such as cathode, heater, focus etc. It definately sounds like a
>> regulation problem. I would buy the repacement HV kit from
>> arcadeshop. I've installed a few of them and I think they are well
>> worth it.
>>
>> Thad
>>
>>
>> Pinx wrote:
>>
>>> Right,
>>> now i am really baffled, not only have i re-capped it but now i
>>> have replaced the transistors at Q901, Q902, Q903, Q904 and replaced
>>> the Zeners at ZD900, ZD901, ZD902. I have also replaced the
>>> resistors at R912, R920, R922, R925.
>>> I put my HV probe in with the monitor switched on and set the HV to
>>> 19500V and still the image on the screen is massive !!!
>>> Starting to pull my hair out now (not that ive got much) any more
>>> idea's anyone ? Should the HV be measured with the game pcb unplugged ?
>>> Pinx
>>> ----- Original Message -----
>>> *From:* Pinx <mailto:pinx.32@tesco.net>
>>> *To:* vectorlist@vectorlist.org <mailto:vectorlist@vectorlist.org>
>>> *Sent:* Friday, April 01, 2005 7:36 PM
>>> *Subject:* VECTOR: SW monitor prob...
>>>
>>> Hi guys,
>>> just recently the WG in my SW has developed a problem where the
>>> image is massive, so you cant see it all on the screen. I have
>>> been told this is "blooming" and so i have just re-capped the HV
>>> section, but i still have the problem. Is there anything else on
>>> the HV board i should replace to cure this problem ?
>>> TIA
>>> Pinx
>>>
>>
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>>
>
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Received on Thu Apr 7 09:19:09 2005