Philips 37PFL4606 No Power

[dick_barton]

Re: Philips 37PFL4606 No Power

I believe that refers to their operating frequency resistance not their DC resistance. As long as it's not open circuit I would say it's fine.

[budm]

Re: Philips 37PFL4606 No Power

BTW, just FYI:
https://www.badcaps.net/forum/showth...t=86564&page=5
This 37" board has the same low Voltage on C946 so the PFC Voltage booster is not working on this 37" board either.

[dick_barton]

Re: Philips 37PFL4606 No Power

Post the voltages on the pins of IC902

[trunks81]

Re: Philips 37PFL4606 No Power

iam getting a very strange measurement, This is with 1K in place

1=0.88V
2=0V
3=0V
4=0V
5=9.76V
6=0V
7=0V
8=0V

[dick_barton]

Re: Philips 37PFL4606 No Power

You have lost the supply voltage (VCC) for the IC. Check you still have the 5VSTBY. If you do then you need to check the voltages on Q907.
If you don't then it's back to measuring the voltages on the pins of IC905

[trunks81]

Re: Philips 37PFL4606 No Power

5V is present ! iam getting the next IC907

B=9.065V
E=9.804V
C= 9,79V

IC905

1=2.83V
2=1.30V
3=5.88V
4=0V
5=NC
6=319V

[dick_barton]

Re: Philips 37PFL4606 No Power

What voltages do you have on the pins of IC902. The voltage at the collector (Q907) appears low. I seem to remember Budm mentioned it as being 15V which it currently is not.

[trunks81]

Re: Philips 37PFL4606 No Power

Only getting an voltage on pins

1=0.88V
8=9.8V

All other pins are 0V

[dick_barton]

Re: Philips 37PFL4606 No Power

This is starting to confuse me.
The transistor Q907 has 9.8V at the emitter which goes to IC902 pin 8 via R947 but Pin 8 has 0V on it? Are you reading the IC pin numbers correctly

[trunks81]

Re: Philips 37PFL4606 No Power

My bad.. i whas counting the pins wrong.. apparently the pins goes like this

1=8
2=7
3=6
4=5

and i whas counting like this

1=5
2=6
3=7
4=8

Only getting an voltage on pins

1=0.88V
8=9.8V

All other pins are 0V

[dick_barton]

Re: Philips 37PFL4606 No Power

You need to recheck this one and your other thread for previous readings given if you have been miscounting the pinouts.
The pin count goes anti-clockwise in a circle. Normally pin 1 is marked on the board or has a dot on the IC next to pin1.

[budm]

Re: Philips 37PFL4606 No Power

You need to recheck this one and your other thread for previous readings given if you have been miscounting the pinouts.
The pin count goes anti-clockwise in a circle. Normally pin 1 is marked on the board or has a dot on the IC next to pin1.

This is really causing a lot of confusing in this thread and the other thread (47"), especially when the pinout is counted wrong.

[trunks81]

Re: Philips 37PFL4606 No Power

should it make an difference if i remove the brownout protection ?

[budm]

Re: Philips 37PFL4606 No Power

should it make an difference if i remove the brownout protection ?

You are getting 4.6V in standby and 5V when TV is turned on, so no need to do anything with the Brownout protection.
I still cannot figure out why both boards are getting only about 10V on C946.

[trunks81]

Re: Philips 37PFL4606 No Power

When i connect mainboard in the tv iam getting 11.4V on C946

[budm]

Re: Philips 37PFL4606 No Power

When i connect mainboard in the tv iam getting 11.4V on C946

The PFC IC and the SMPS IC need 12.5V for it to startup and run, so if you check the Voltage on the main cap right now what Voltage do you have, 395VDC?

[trunks81]

Re: Philips 37PFL4606 No Power

The PFC IC and the SMPS IC need 12.5V for it to startup and run, so if you check the Voltage on the main cap right now what Voltage do you have, 395VDC?

Its 309VDC

[budm]

Re: Philips 37PFL4606 No Power

Well, as you can see, the PFC Voltage booster is not working due to low Voltage on C946, we know that we need to have about 15V on C946, that is the reading from good working board that you already returned the 47" TV to the customer, and now we are trying to fix the 37" and another 47" which both of them have the same problem, low Voltage on C946.
I still do not know why both boards are doing the same thing.

[trunks81]

Re: Philips 37PFL4606 No Power

Oke the tv boots and iam getting 14.5V on C946, Only the PFC is around 300V
Allready checked the three 1M resistors and they read fine out of circuit

[budm]

Re: Philips 37PFL4606 No Power

Oke the tv boots and iam getting 14.5V on C946, Only the PFC is around 300V
Allready checked the three 1M resistors and they read fine out of circuit

So what did you do to get 14.5V on C946 back.
Try unplugging the power for 5 minutes the run the Voltage log test on the main and C946 using 1K force on to see what we have.