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Old 3rd October 2007, 09:11 AM   (permalink)
Default Phillips tv dead

Hello all,
I have a Phillips PW6506 with a dead screen and no sound.
The fault originated with rapid clicking when first powered up and then would take about ten on and off with the power to gain a steady picture. Yesterday I suddenly lost the picture and the small power light no longer illuminates. I know that I shouldn't have let the go this far but this is where I'm at. I don't suppose that the clicking was due to a contactor which now has burned off contacts? Or could it be a capacitor fault as I would have to wait until the small red light light went out before switching on again. Also the picture would take a few minutes to stabalize on the right hand side of the screen.
Hope that someone can help.

Cheers BD
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Old 3rd October 2007, 10:47 AM   (permalink)
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It could be a line output transformer fault - I think the ticking noise is a symptom.
If you are lucky, then it may be just a dry joint on one of it's pcb pins.
If it has blown, it is an expensive repair and they can also cause the driver power transistor and other parts to blow.

WARNING!! A TV HAS DANGEROUS VOLTAGES PRESENT EVEN SOME TIME AFTER POWER OFF!
DO NOT ATTEMPT ANY REPAIR UNLESS YOU ARE FULLY EXPERIENCED IN WORKING WITH HAZARDOUS VOLTAGES!

(I would now consider just getting a new LCD tv if any old tube type one fails rather than trying to repair it)
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Old 3rd October 2007, 10:57 AM   (permalink)
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A VERY common fault on them is a small blue disc capacitor in the line output stage, these usually go S/C with obvious burn marks on them, and often a 'death smell' - I did one last night.

The capacitor is the tuning for the line output stage, so it's essential you replace with the correct value - the one I did was 1500pF 2KV.

BTW, in the set I did the capacitor was C2420.
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Last edited by Nigel Goodwin; 3rd October 2007 at 11:03 AM.
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Old 3rd October 2007, 11:27 AM   (permalink)
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Nigel Sir,
I have a Phil;ips model 21PT2125/94/c (Indian made).

More frequenctly it currupts the contents of EEprom . I had got it serviced by paying for a chip replacement. Still things repeat. At the time of failure, the set shows an extra display Stereo on top left. The picture starts binking at 1 sec interval, and audio fails.

I feel it might be due to power flicks, and an analysis indicated that the EEPROM pins are not protected by 5V zenors on the address and SCL and SDA pins.

should i venture to mount them.?
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Last edited by mvs sarma; 3rd October 2007 at 11:32 AM.
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Old 3rd October 2007, 11:47 AM   (permalink)
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You might try them, see if it helps? - but EEPROM corruption is common on many modern TV's.
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Old 3rd October 2007, 12:18 PM   (permalink)
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Thanks Nigel Sir.
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Sarma.
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Old 3rd October 2007, 12:49 PM   (permalink)
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He called you Sir, twice! Have you been knighted by the Queen herself and not informed any of us here about that dubious title?
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Old 3rd October 2007, 01:17 PM   (permalink)
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Quote:
Originally Posted by HiTech
He called you Sir, twice! Have you been knighted by the Queen herself and not informed any of us here about that dubious title?
I was trying to keep it quiet!
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Old 3rd October 2007, 02:09 PM   (permalink)
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I beleive i said Nigel Sir , but not Sir Nigel

It is out of respect, and if it is uncomfortable to the British way of life , I beg pardon.
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Old 3rd October 2007, 02:12 PM   (permalink)
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Quote:
Originally Posted by mvs sarma
I beleive i said Nigel Sir , but not Sir Ngel

It is out of respect, and if it is uncomfortable to the British way of life , i beg pardon.
It's not something that is done in English, but as you have your location filled in I knew English wasn't likely to be your first language. Unlike the uncouth Americans I wouldn't criticise someone for being excessively polite and respectful, particularly when it's a feature of their culture.
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Old 3rd October 2007, 04:53 PM   (permalink)
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Thanks for the replies.
There is a steady bird like chirping sound from the line output transformer.

Cheers
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Old 3rd October 2007, 09:27 PM   (permalink)
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Quote:
Originally Posted by bigduke
Thanks for the replies.
There is a steady bird like chirping sound from the line output transformer.
It's tripping - the disk capacitor causes this, as would the line output transistor being S/C (and other things) - but check the capacitor, the odds are it's that!.
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Old 4th October 2007, 11:40 AM   (permalink)
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Nigel,

Is the capacitor mounted on the main pcb or on the tube pcb?
Cheers BD
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Old 5th October 2007, 08:42 AM   (permalink)
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Quote:
Originally Posted by bigduke
Nigel,

Is the capacitor mounted on the main pcb or on the tube pcb?
Cheers BD
On the main PCB, near the line output transistor and line output transformer.
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