Re: Amplifone question

Well, I tested and verified that the problem *isn't* the red can. The BU406D
transistor went bad. The bad news is my Wintron died also. It reads all red
on the ring tests both in and out of circuit. It was brand new too! I have to
assume that it may have been bad to begin with because I've blown 24v
regulators before and I've blown BU406D's in the process of trying to rebuild
other HV units and never had problems with the HV transformer going bad. It
was working for about 10 minutes, but when I was carefully adjusting the focus
and brightness it went out.

I'm praying they'll be willing to send me another one. So, let me ask a few
more simple questions;
1) Has anyone had a new Wintron go bad and if so, do you know why?
2) I didn't know this until after, but the overvoltage protection pot (R17) was
turned completely clockwise. I assume it's probably not good to have the
overvoltage protection turned off while fiddling with the brighness and focus.
Would this be a correct assumption?
3) For a 25" inch monitor, does anyone have a recommendation for the value of
R6 used with a Wintron? I understand increasing the resistance also allows you
to increase the KV. The resistor is currently 3.9k.

Thanks for reading. Any advice is appreciated. ~sigh

Matt

Matt Rossiter wrote:

> I got another Amplifone monitor working today. It was looking really
> good and I was very happy with it. Unfortunately, while I was adjusting
> the brightness the picture all of a sudden went blank and then the 7824
> regulator blew up with a big bang. I replaced the 7824 and it fried
> again. I'm pretty sure it's that stupid mystery can because I've had
> this problem before. I checked some of the components in the
> overvoltage protection circuit.
>
> I just have a few basic questions.
>
> 1) Is it common for the magnetic correction can to go bad.
> 2) Is there a way of testing it to verify that it's bad. Would it be
> stupid to do a simple ohm test to verify there's no short?
> 3) Is there any hope of being able to get the part replaced without
> pulling it off another HV board?
>
> Thanks.
>
> Matt
>
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Received on Fri Jun 15 04:21:34 2001