Philips 42" 42PFL5432D/37 power light no picture please help

[oceans4me]

I have a red light when plugged in when button is pushed i get a green light.
No picture, I have tested all caps and replaced bad ones. Have replaced Q901 that tested bad and replaced D912 which was shorted. Fuse F901 which blew several times but is ok now. Replaced IC910 which had tested bad.
I don't have 24v to vbl. Is there a chance that transformer T905 is bad? I read .01 ohms to ground on legs 9,8,7. If anyone has a idea of what i should check next PLEASE let me know.

[Dgtech]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Just taking a quick look at the board, it seems like the two zenors took a little heat. There are lots of threads on this set. Im sure there should be a list of usual failing components on this power board. I think I may have started one somewhere.

[tom66]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Jamicon capacitors are not suitable replacements for the failed ones.

[oceans4me]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Jamicon capacitors are not suitable replacements for the failed ones.

Ok i will replace them. What brand is a good replacement for the caps 1500uf 35v? Where is the best Place to buy them at? Thanks Pat

[tom66]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Panasonic FM, FR, FC.
Digikey: http://www.digikey.com/product-searc...s=fm+1500uf+35

[oceans4me]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Just taking a quick look at the board, it seems like the two zenors took a little heat. There are lots of threads on this set. Im sure there should be a list of usual failing components on this power board. I think I may have started one somewhere.

I have read alot of the threads on the same tv set but most of them had voltage going to vbl mine only has 2.3v? Do you remember any of them that had a bad transformer? One side of T905 on pins 3,4,1,2. I read 389v pins 9,8,7. I read 0v. I thought that was where the 24v came from but might be wrong. I will test the two zenor diodes thanks

[oceans4me]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Panasonic FM, FR, FC.
Digikey: http://www.digikey.com/product-searc...s=fm+1500uf+35

Digi-key is out of stock for the 35v 1500uf any other suggestions. thanks

[tom66]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

These instead then.
http://www.digikey.com/product-detai...447-ND/2433581

[sunn1044]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

I have a red light when plugged in when button is pushed i get a green light.

No picture, I have tested all caps and replaced bad ones. Have replaced Q901 that tested bad and replaced D912 which was shorted. Fuse F901 which blew several times but is ok now. Replaced IC910 which had tested bad.

I don't have 24v to vbl. Is there a chance that transformer T905 is bad? I read .01 ohms to ground on legs 9,8,7. If anyone has a idea of what i should check next PLEASE let me know.

[budm]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

@sunn, I doubt that the transformer is bad, What DC voltage do you have on that large 450VDC main filter cap, it should have about 160vdc when TV is OFF and aabot 370~400VDC when TV is ON, you have to measure it right at the two legs of the cap, be creful since you are working in the HOT side of the circuit.

[sunn1044]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Thank u very much for respond can u please tell me
What is the voltages on or how to test the Tea1507p ic

[budm]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

You can do the resistance reading of all the pin against the Ground pin. But you should check the DC voltage aright the two legs of that large main filter cap, it should have about 160VDC when TV is OFF (Standby), and around 370~400VDC when TV is on, you will have to real careful since you will be working in the Primary side of the circuits.
You should also check those components in red circles, and the DC VOLTAGE on the VCC pin

[sunn1044]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

HI bud I did the test on the on that large 450VDC main filter cap, and I have 160vdc when tv off and 395 when on

[sunn1044]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

I took out main board and found some bad cap will that cause it not to get 24v

[budm]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

"and I have 160vdc when tv off and 395 when on" That is good, the PFC Voltage booster, and Standby power supply are working, main board is sending out correct signal (PS_ON) to turn on the power supply. So we now have to look into the 24V power supply section next, the same SMPS IC is used in the 24v as used in the standby power supply. Did you do the resistance reading test yet on the IC?
Any bad caps you found should be replaced first before going any further, otherwise you will be chasing your tail.

[sunn1044]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

I check ic 904 pin 1 5.7v pin 3 0v pin 4 .6v pin 5 0v pin6 0v pin 8 163v
please let me know if this is right Thank u v much

[kevinm34232]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

I had a Philips with lightning damage, after replacing common diodes and some other parts got the TV to come on but no backlight, Tom helped diagnose that problem to the IC1702 TEA1611T. See here:

https://www.badcaps.net/forum/showthread.php?p=342824

[budm]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

So what are the resistance reading of the IC904 as requested? Right now the pin1 VCC is way too low for the IC to run, this can be due to bad startup cap C921 as shown in the diagram, or the IC has an internal short (low resistance).

[sunn1044]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Ok bud I will check res let u know n Thank u m

[sunn1044]

Re: Philips 42" 42PFL5432D/37 power light no picture please help

Hi bud should I test for res with the Ic in the board or take it
Out of the ps and I have a dmm set it 200 ohms and test from ground
Throughout 8