Philips 42pf5320/10 PSU

[cormicar]

My philips tv died the other day. Green power light on but black screen. Changed capacitor that i thought was gone and that didnt bring tv back. I then found a dead slow blow fuse on psu and changed that and now i have relay clicking and screen coming on for a couple of seconds and then turning off. I also noticed a lot of buzzing from psu.
There were mini dials on the psu that i moved and may not have put back to the correct position. Could this be a problem. One dial was labelled VS and the other vscan. Perhaps i should put the original cap back in??
Any advice would be greatly appreciated.

[ReeceyBurger123]

Re: Philips 42pf5320/10 PSU

Why would you put a bad cap back in the Tv ? Also have you a DMM ?

[cormicar]

Re: Philips 42pf5320/10 PSU

Im thinking now that perhaps it wasnt a bad cap as replacing it didnt resolve the issue. Im only going on a very slightly raised head on the cap. Do you know what the dials on the psu are for?

[cormicar]

Re: Philips 42pf5320/10 PSU

I have a dmm but it doesnt measure capacitance.

[ReeceyBurger123]

Re: Philips 42pf5320/10 PSU

Ok, have you images of the board please as there is a few different ones used in this set ? Also do you know how to check for S/C ? I recon you have some blown power devices for the Vs rail as you had a blown fuse.

[cormicar]

Re: Philips 42pf5320/10 PSU

This is the pic of my psu. The chassis of my tv is lc4.9e AA.

The fuse I replaced is under the heatsink on the left (marked in blue). Although it could have been under the heatsink marked in red.

I also circled in blue the 3 mini dials that I was talking about.

I have no idea how to test for S/C.
Thanks

[ReeceyBurger123]

Re: Philips 42pf5320/10 PSU

Hmm and do you get the Vs supply ? A fuse does not blow for no reason something cause it to go pop, normally the Vs fets blow as technically they take a shorted load on start up which strains them a lot.

[cormicar]

Re: Philips 42pf5320/10 PSU

I do not know what the VS and VA voltage on this tv should be as there is no sticker on the unit to advise what it should be. Any ideas?

[ReeceyBurger123]

Re: Philips 42pf5320/10 PSU

There will be somewhere, but Vs should be 210v or so and Va should be £60v or so.

[cormicar]

Re: Philips 42pf5320/10 PSU

Ok. I found what they should be and measured and they were a little out. I adjusted the mini potentiometers and got voltages correct. Buzzing has quietened down a bit. I noticed when i disconnect the main av board from psu, the psu stays on.

[cormicar]

Re: Philips 42pf5320/10 PSU

Just a quick update to say my TV is back working. Thanks you Reecey for pointing me in the right direction by checking VS voltage. This helped me discover that the little dials on the psu were to change the voltages of the vs and va supply. After correcting these voltages and leaving the TV unplugged for an hour, it turned on no problem with no buzzing.