Re: Philips 32PW6006/01 originally HOT S/C...
- From: "geno419@xxxxxxxxx" <geno419@xxxxxxxxx>
- Date: 23 Aug 2005 18:21:40 -0700
Did you look at your HOT drive waveforms? coupling caps, and bypass
caps.
Look for a missing or distorted waveform.
JamesQB wrote:
> Hi everyone,
>
> I've got a sod of a TV set here which is puzzling me and I hoped that
> someone here more knowledgable than myself might be able to offer
> some advice.
>
> It uses the L01.1E chassis and is a 32" widescreen. Originally it was
> tripping which turned out to be S/C line output transistor (or HOT as
> some call it), probable cause being C2455 (47uF/25V) in the line
> driver circuit, low in value at 36uF. This is apparently the usual
> cause with this chassis, and there is also a PSU kit available for
> the SMPS in the event that the set continually kills the line output
> transistor.
>
> Anyway, replaced the transistor (BU4508DX) with a BU2508DF and
> replaced the cap with the only available one (47uF, 63V). The set now
> comes on. I don't know if it's usual behaviour for this set, but it
> takes a while for the raster to appear, during which a couple of
> relays click. After 2 or 3 seconds or so, the set then shuts down. It
> seems the line drive is taken away when this happens, as the HT line
> rises from its value of 126V under load, to its 140V unloaded
> potential.
>
> Although it shuts down quickly, I found that I could keep it on longer
> by going through the channels; it seems to stop the shut-down process.
> I brought up a channel with a very good undistorted image, stopped
> flicking through the channels, leaving it one this one, and then the
> set died after a few seconds as normal. The transistor doesn't seem
> to be getting terribly hot during this.
>
> Incidentally, it may just be me, but the line stage doesn't sound
> right... the high-pitched noise coming from the LOPT seems to have
> harmonics by the way there is a 'flicker' or 'roughness' to it. It's
> hard to describe.
>
> Any ideas or suggestions would be much appreciated as this has been on
> the bench too long now and I'm tired of its 32 inches taking up most
> of the workspace and falling over its gigantic rear cover!
>
> Thanks to all who even read this, and especially to anyone who
> replies.
>
> James
.
- References:
- Philips 32PW6006/01 originally HOT S/C...
- From: JamesQB
- Philips 32PW6006/01 originally HOT S/C...
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