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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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27th Nov 2022, 7:47 pm | #1 |
Hexode
Join Date: Mar 2008
Location: Manchester, UK.
Posts: 478
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Philips 1200u LOPT sparking
So I powered up my Philips 1200u since queen Elizabeth funeral. It would not start up, faint and out of sync picture.
I assumed it was my hedgehog as it has sometimes played up assuming a dry joint or something. I decided to open the back and check all valve were seating and I could hear arching and can see it in the LOPT cage. Ive turned it off and hope I haven’t made it worse by leaving it earlier assuming the fault was somewhere else.. Ive not got round to taking the chassis out but rather concerned. What would the likely cause be? Could it be a spider something or could it be worse like the LOPT insulation breaking down? Hoping Mikey405 sees this as he has worked on it.
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27th Nov 2022, 8:01 pm | #2 |
Hexode
Join Date: Mar 2008
Location: Manchester, UK.
Posts: 478
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Re: Philips 1200u LOPT sparking
Just had a closer look at it.. i can see the resistor! i thought that was supposed to be covered in wax! Must be the heatwave…
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28th Nov 2022, 2:55 pm | #3 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: Philips 1200u LOPT sparking
I've not looked at the transformer layout but are you sure that is a resistor and not the EHT smoothing cap? If I remember it is buried in a little wax filled coffin on the front of the TX. Chop it out as a test. If it is the cap the chassis will work perfectly OK without it. J.
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28th Nov 2022, 11:37 pm | #4 |
Hexode
Join Date: Mar 2008
Location: Manchester, UK.
Posts: 478
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Re: Philips 1200u LOPT sparking
Hi John, it’s definitely the resistor, and yes you’re right. Its supposed to be in it’s little coffin covered in wax, but that wax has all gone, the resistor is now arching with the cage.
I suspect the wax melted since the last heatwave, the room it was in reached 40°C! I wonder if silicone rubber is a good insulator.. Anyone tried this?
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What have you bought now?? Last edited by Electricdreams; 28th Nov 2022 at 11:47 pm. Reason: Included coffin ⚰️ |