Philips 37pfl5405H/05

[redriddick]

Hi Guys,
I have one of these tvs which suffered the 3 red led flashes.I have opened up the tv and it has the PLHD-P982a psu.
It has now started to blow the fuse on the psu.Resistor at location R517 smokes when I install a new fuse and switch on.
I cannot find a schematic for this psu.I have the service manual alright.
I have attached pics of psu,

[nomoresonys]

Re: Philips 37pfl5405H/05

this is the closest I see, might be similar to yours, http://www.toms-service-manuals.com/...h=Submit+Query

[selldoor]

Re: Philips 37pfl5405H/05

Check diodes - especially D210 prone to failure - does the resistor test correct resistance?

[redriddick]

Re: Philips 37pfl5405H/05

D210 seems to have failed.I will desolder the resistor and test.

[selldoor]

Re: Philips 37pfl5405H/05

Lift one leg of D210 and test again. If it has failed shorted that may be the problem but it may have taken out other parts. Test the diode pads and see if a short still shows.
Perhaps google Dim Bulb Tester and make one up to save blowing more or new
components.

[redriddick]

Re: Philips 37pfl5405H/05

Diode showing no voltage.Pads are showing .286

[redriddick]

Re: Philips 37pfl5405H/05

What should that resistor be reading???

[selldoor]

Re: Philips 37pfl5405H/05

What should that resistor be reading???

Well if it is red red silver gold black ignoring the black it could be 0.22ohms

[selldoor]

Re: Philips 37pfl5405H/05

Diode showing no voltage.Pads are showing .286

You should be testing the diode using diode setting or ohms not volts
perhaps read this start at post 19.
https://www.badcaps.net/forum/showthread.php?t=10419

[redriddick]

Re: Philips 37pfl5405H/05

Ya i tested the diode using diode setting and getting nothing.
I think the resistor is orange,orange,silver,gold,black which is .3 ohms I think??

[redriddick]

Re: Philips 37pfl5405H/05

Taking out one leg on the resistor is ok for testing??

[selldoor]

Re: Philips 37pfl5405H/05

If the bands are orange it is 0.33 ohms - yes just need lift one leg but take care in case it snaps. You can try first with it on the board.

[redriddick]

Re: Philips 37pfl5405H/05

Have tested it in and with leg out and seems to read .33 ohms,so should be ok.

[redriddick]

Re: Philips 37pfl5405H/05

I have ordered the diode so will have to wait until I receive it.
Will post back when I get it.
Oh I will make up a dim bulb test from bits and pieces I have lying around!!!!

[nomoresonys]

Re: Philips 37pfl5405H/05

beware when testing snubber diodes in diode mode, they read differently than other diodes, found that out the hard way, on a samsung lcd, ruined a good diode removing and breaking it, because I thought it was already bad.

[redriddick]

Re: Philips 37pfl5405H/05

Ok so I have replaced the diode and made up a dim bulb tester.Still no power on tv and bulb burning brightly so the diode must have taken something else out.
No voltages at pins to main board not even standby.
Where to next guys????

[redriddick]

Re: Philips 37pfl5405H/05

Checked bridge retifier.
Tested shorted in pcb.
Removed and tested ok.
MMMmmm

[redriddick]

Re: Philips 37pfl5405H/05

bump

[drussell]

Re: Philips 37pfl5405H/05

Checked bridge retifier.
Tested shorted in pcb.
Removed and tested ok.

Well, just keep following it along and see where the short is. Shorted MOSFET/IGBT is the most likely but could be a shorted filter capacitor or other component... Keep working your way along, testing the next components in the circuit by disconnecting each and testing out of circuit until you find the short or disconnect something and the short disappears.

[redriddick]

Re: Philips 37pfl5405H/05

Could I use a 6a 600v bridge rectifier instead of a 4a 600v????