Samsung widescreen tube problems - repairable?

ProDave · Joined: 06 Mar 2007 Posts: 13

I have two JVC TV's with Samsung W66QDE993X486 28" widescreen tubes. Both have different tube faults:

First one has a colour purity problem. For instance when displaying the blue no signal screen, the top left corner of the screen is red, not blue. Is this repairable, i.e is there any adjustment to re set the colour purity? I have tried degaussing with no improvement.

Second one has an intermittent fault. Sometimes the picture is fine, then the tube starts clicking (something arcing inside?) and the picture changes. What happens is the colour purity goes haywire. Again when displaying the blue no signal screen, the left of the tube is green, and the right is red, with only the centre portion being the correct blue.

It's not an electronic fault (confirmed by swapping chassis) but a tube fault. I suspect this one is not repairable.

Assuming both faults are not repairable, where's the cheapest place to buy a replacement tube and how much? (in the UK)

gary · Joined: 05 Apr 2005 Posts: 584 Location: MANCHESTER, uk

best price i can find for crt is from charles hyde @ £226.91 + vat. is it worth it?

ProDave · Joined: 06 Mar 2007 Posts: 13

ProDave · Joined: 06 Mar 2007 Posts: 13

I have sort of found a solution to the first of these sets (the second one has been returned as BER)

This first one works fine except for the colour purity problem. I tried all the adjustments on the tube, but these only affect convergence, not purity. I even tried loosening the scan coils and re positioning them, but no improvement was obtained.

Having set everything back, thinking it was a lost cause and I had nothing to lose I started experementing with some permanent magnets. I quickly found by holding a magnet close to the front to the tube in the affected corner, I could "fix" the colour purity. A little more experementing led to the same "cure" with the magnet held behind the offending corner. Further experimenting revealed that by selecting the correct strength magnet, it could be "cured" with the magnet touching the back of the tube.

So there it is. I have "fixed" what appeared to be a duff tube by sticking the magnet to the back of the tube with duck tape.

It will be interersting to see if the "fix" is permanent or whether it degrades further over time. But in the absence of a technically correct cure, this has at least for the time being allowed the set to continue being used rather than junked.