Hi to all you folks out there in TV land. I wonder if any of you may be able to help a) diagnose my ailing TV and b) advise where I could get parts for it:

I have a Philips Matchline IDTV 100Hz Digital Scan model 32PW9544 and it is showing signs of colour trouble. When veiwing the colour seems to intermittently "warm" up by going reddish. If you watch a purely white screen, you can see it cycling through colours with a bias for the warmer shades.

I took it to my local repair centre who watched it for the best part of two weeks and said there was nothing wrong with it. After getting it back home, it behaved impecably for about 8 weeks. Now it has once again started giving the colour trouble.

Would any of you knowledgable folks be able to help?


Many Thanks
Mike Burton. Printer engineer knowing very little about tellies!

[greenapple]

Apologies for resurrecting a rather old thread, however I see there were no responses and I have just started having what seems exactly the same problem with my TV - same model, over six years old now.

It's hard to describe the colour problem a lot better than it has been, it's definitely clocking through making the screen red, blue or green heavy and this can be accompanied by a small amount of colour bleed. It can sometimes resolve itself and then be fine for a few minutes before it happens again. And tonight, for example, it behaved for most of the evening. When it happens, the colour changing seems sporadic, but may be several times a second, making me want to describe it as a flicker, although I understand that's the wrong term in this context.

Checked everything I can think of, inputs, cables etc. and various settings on the set. If you turn the set off and back on again the problem doesn't seem to come back for maybe ten minutes, so I can only presume it is indeed the set that has the problem. Apart from a proper fault, I can only think it has suddenly developed a dislike for the weather as things have got warmer again. The set has always been in the same spot and nothing like this has happened before.

I'd be grateful for any ideas please.

[Teamscoop]

Our Philips 28" 6515 looks like it may turning its toes up. We have a very slight flicker in the colour although this sometimes goes haywire and then the picture 'pops' and all is well. The problem (virtually) goes away if the set is turned off and on. I also have very thin green lines (about 12 or so) running across the screem at a 30 degree angle. Rather like an ocilloscope trace! This is only visable on veiwing very dark picture material. Hmmmm, sounds like I better start digging a hole in back garden. Shame, it's a great picture! Is it worth getting an engineer to look?

[greenapple]

Hi Teamscoop. It's weird, from the lack of response I guess this colour issue is unusual - I've had no pops or lines though.

Does anyone know if this is something specific to Philips sets? I've had a look through the board and can't seem to find the same problem. Could anybody offer an opinion on whether this sounds fixable or not?

Cheers!

[Emjay111]

Hi both,

OK, LG / Philips widescreen tubes are well known for failing.

Here's a list of the usual symptoms:

1) One very bright colour (R G or B) with diagonal flyback lines all over the screen. The set usually wont tolerate this for long before shutting down.

2) A noticeable increase in one colour. This would make white no longer a true white. However, this can also be caused by adjustment and often a tube that is going this way can be adjusted correctly again to give it a few more months / years life.

3) Very bright white saturated pic for a second before the set shuts down.

4) Pulsing one bright colour (R G or B) then back to normal - intermittent

5) Exceptionally poor focus. Can often just be adjusted so the pic looks reasonable in the centre, but not too hot in the corners. When text is displayed, this will then prove the tube is really still well out of focus. This fault we've only seen on the 32" versions. Often Pansonic TX-32PK and DK series sets suffer from this, because underneath the lable on the tube that says "Panasonic" is a Philips type number ! :-(

Most of these faults seem to happen on the 28" range of tubes. We've not seen many problems with the 24" widescreens.

An engineer can test the CRT (tube) with a B & K or Muter tube tester, but they cannot repair or correct some of the faults (heater / cathode shorts) reliably. If they say they can - they are lying. There are a number of very dubious bodges that temporarily work around the problem, but I don't think these are safe, and certainly invalidate any safety features that were designed into the set when it was made.

The simple test for a failing tube (and DON'T do this at home - you could knock the neck off the tube or electrocute yourself) - is to tap the neck of the tube whilst watching the picture in a mirror. If the tube flares up one specific colour, or the fault occurs, chances are the tube is defective.

Put it this way, we're losing many sets per week from our rental stock because of this problem.

LG / Philips Displays (who make these tubes in many factories all over the world) have declared each manufacturing plant bankrupt. There will be no more Philips widescreen tubes made thank God !

Cheers

MJ


PS: Teamscoop - I'd say yes - thats definately a faulty tube. Time to say goodbye to the set. A new widescreen CRT for a 28" set is about £130 + VAT trade.

[greenapple]

Thanks for such a thorough reply Emjay111. I did wonder if I could gather any info or do anything from the service mode, but mine was apparently made before the revisions where you can access that with a normal remote code.

Thanks again for your help!