Repaired the PSU QX801, QX802 together with associated smd resistors and smd diodes. When powered up everything fine but after a few minutes transformer TS801 and TX801 began to hiss more than usual. After 10mins psu had failed again just repaired it again but after a few minutes once again the same transformers are hissing more than usual. Switched it off again now in case it fails again. Anybody any ideas why transformers are hissing or is it just due to ageing transformers? I have repaired a number of these power supplies in the past without any such problems.
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Re: PS50Q97HD PSU repair bn44-00162a
Any replies re above appreciated! -
Re: PS50Q97HD PSU repair bn44-00162a
I think good quality pictures of the power supply board would definitely get you more attention. Reason being is that very few people can/will look up the model number and then try to fetch a service manual for the PSU to look up what those parts you mentioned do. I, for example, rarely look up service manuals, because I'm bad at finding them and I usually have an easier time understanding what the circuit does by looking at it than trying to figure it out from multiple pages in the SM.
As far as those transformers hissing - are these for the backlight inverter or the main transformer. I'm only guessing the latter.Last edited by momaka; 07-03-2014, 08:38 PM.Comment
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Re: PS50Q97HD PSU repair bn44-00162a
That particular power supply after being repaired a second time is now ok. Having said that the VA transformer still continues to produce a louder hiss than normal.
There doesnt appear to be any cracks on the ferrite and all voltages are as they should be. It doesn't become noticeably louder until after about 5mins of running. Thanks for your reply.Comment
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