Philips 37PFL4606 No Power

[dick_barton]

Re: Philips 37PFL4606 No Power

The 9.8V is just too low and I can't see why. The +5V SB is working so IC905 must be working. Can you measure the voltage across ZD908 and test capacitor C946

[trunks81]

Re: Philips 37PFL4606 No Power

Hello

The voltage across ZD908 is 7V, and the cap C946 measure in circuit 48uf and also outside of it.

[dick_barton]

Re: Philips 37PFL4606 No Power

ZD908 is an 18V zener so with voltage across it appears to be OK.
Can you measure R959. Using meter in diode mode check across D916 in both directions.
Just out of curiosity can you also measure the resistance between the 12V supply pin and chassis and also the 24V pin and chassis of the connector.

[trunks81]

Re: Philips 37PFL4606 No Power

R959 is 4,7ohm both ways,
D916 is working measure 0.5V and reverse OL
12V to ground is 1Kohm
24V to ground is 2.4Kohm

[dick_barton]

Re: Philips 37PFL4606 No Power

There doesn't appear to be an issue on the secondary side of the 12V and 24V supply.
R959 and D916 check out OK.
Need to think about what else could be causing the problem but I'm fairly sure the 9.8V is the issue.

[budm]

Re: Philips 37PFL4606 No Power

What Voltage do you have when measure at the two legs of the cap C946 when 1K resistor is in place and not in place?

[trunks81]

Re: Philips 37PFL4606 No Power

When in place iam getting 9.8V and removed 8.1V

[budm]

Re: Philips 37PFL4606 No Power

When in place iam getting 9.8V and removed 8.1V

OK, check the resistance between the two legs of C946 and C922, the meter should show very low resistance at the beginning then it should be in K Ohms range after 10 seconds or so.
Also check the resistance between the positive leg of C946 and C922 in both directions of the probes.

[trunks81]

Re: Philips 37PFL4606 No Power

Hello


I do not see that the resistance is low in the beginning
C946 = 7.14Kohm, and reverse 56.2Mohm
C922 = 8.2kohm, and reverse 104kohm

Between the positive legs of C946 and C922 51Mohm and reverse 12kohm

[dick_barton]

Re: Philips 37PFL4606 No Power

.

[trunks81]

Re: Philips 37PFL4606 No Power

What do you mean ?

[trunks81]

Re: Philips 37PFL4606 No Power

C920 measure 8kohm and reverse 100kohm

[trunks81]

Re: Philips 37PFL4606 No Power

ive have an other board from an 47 inch model.. which has an short in it so the fuse keeps blowing C920 and C915,C922 all measure 270ohm

[dick_barton]

Re: Philips 37PFL4606 No Power

ive have an other board from an 47 inch model.. which has an short in it so the fuse keeps blowing C920 and C915,C922 all measure 270ohm

It would be better to post this as a new thread otherwise it will become confusing.

[trunks81]

Re: Philips 37PFL4606 No Power

oke sorry.. any other ideas to get this one running?

[dick_barton]

Re: Philips 37PFL4606 No Power

At the moment I don't but others may well step in to assist.

[trunks81]

Re: Philips 37PFL4606 No Power

Tommorrow i have an working power supply, Hopefully we can reverse engineer it back ti the fault in the other one's

[budm]

Re: Philips 37PFL4606 No Power

Hello


I do not see that the resistance is low in the beginning
C946 = 7.14Kohm, and reverse 56.2Mohm
C922 = 8.2kohm, and reverse 104kohm

Between the positive legs of C946 and C922 51Mohm and reverse 12kohm

OK, they look OK, I was looking to see why you only getting 9V, I need to look further in the circuit.

[budm]

Re: Philips 37PFL4606 No Power

Hello

Between the legs of C907 iam getting 309VDC,

Edit is allready replaced D901,Q902 and R919 because board whas doing notting in the begining

I need clarification about this.
Did you have 5V Standby before replacing those part in the PFC circuit? Were those parts bad?

[trunks81]

Re: Philips 37PFL4606 No Power

Those parts were bad. so needed to replace them.. did not measure 5V because fuse kept blowing.