PHILIPS 42PFL4606H/58 NO backlights

[whtiey549@gmail.com]

Hi all, I have a philips 42pfl4606h/58 and there are no backlights. I can hook up my laptop and play video through the set. Sound but no picture. I can use a flashlight and see picture through the screen.

I will attach some photos. Are the CCFLs good? How can I test the board? Without Electrocuting myself. Any help would be greatly appreciated.

[nomoresonys]

Re: PHILIPS 42PFL4606H/58 NO backlights

underside of your board is filthy, clean it up first, can use isopropyl alcohol and a toothbrush, then let it dry for at least an hour, then touch up the bad solder joints, then retry it, you're right about the DEADLY voltage, be careful, just touch the edges of the powerboard, can check the voltage of the big filter capacitor with a multimeter, they usually have 400 volts or so when powered up and can hold a big charge for a while, can discharge them with a resistor, check youtube, I use a resistor held by insulated plyers, examples of bad joints there: https://www.google.com/search?q=bad+...ih=607&dpr=1.5

[whtiey549@gmail.com]

Re: PHILIPS 42PFL4606H/58 NO backlights

There's 315 Volts across the capacitor, and I've cleaned the board and checked continuity across the board and there's no bad joints as far as I can tell. What else do you think I should check?

[lotas]

Re: PHILIPS 42PFL4606H/58 NO backlights

There's 315 Volts across the capacitor, and I've cleaned the board and checked continuity across the board and there's no bad joints as far as I can tell. What else do you think I should check?

Checking the health of the PFC node is carried out by measuring the DC voltage on the capacitor of the mains rectifier. In operating mode, it should be about 380V, in standby mode, about 300V.