Philips 47PFL5704D F7 No Power

**PlainBill** · 01-05-2012, 12:10 PM

Re: Philips 47PFL5704D F7 No Power

What the heck is going on here!!!! We had a bunch of threads that opened with something like "My TV dont work. how d o i fix itt?"

Now you come along and give a great description, and provide excellent pictures. It's great.

Sorry, you only get a silver star. If you had Googled buy FSQ510 you would have discovered Mouser Electronics in Texas has them available for $1.18, shipping will run $5, and you should have it on Saturday.

PlainBill

**retiredcaps** · 01-05-2012, 01:13 PM

Re: Philips 47PFL5704D F7 No Power

findchips.com is fast easy way to find parts as it searches all the major distributors for you.

http://www.findchips.com/avail?part=FSQ510

**kolpro** · 01-05-2012, 01:42 PM

Re: Philips 47PFL5704D F7 No Power

LOL.....Thanks for the fast response I googled FSQ510 but not "buy FSQ510" I should have thought of that.

Thanks
again

**retiredcaps** · 01-05-2012, 01:49 PM

Re: Philips 47PFL5704D F7 No Power

Originally posted by kolpro

Then I begin to think what would have caused this problem and if I replace the chip will it blow again. So any help would be gladly appreciated.

Datasheet is at

That pin looks like the Drain from figure 3. The description says high voltage power SenseFET drain connection.

**kolpro** · 01-05-2012, 02:00 PM

Re: Philips 47PFL5704D F7 No Power

Yep I just check that datasheet as well does this give you a flag as to maybe why it blew and maybe if I should be checking something else as well?

**kolpro** · 01-05-2012, 04:44 PM

Re: Philips 47PFL5704D F7 No Power

Thanks much I just ordered the part from Mouser Electronics and once the part comes in I'll post the results. I went ahead and ordered 2 just for the heck of it only cost me $11 bucks with shipping.

**retiredcaps** · 01-05-2012, 06:26 PM

Re: Philips 47PFL5704D F7 No Power

Originally posted by kolpro

Yep I just check that datasheet as well does this give you a flag as to maybe why it blew and maybe if I should be checking something else as well?

I would check the following for potential shorted components:

- bridge rectifier
- power mosfet
- all diodes in and around U101
- R104 - see if it matches its color band

Good call on ordering 2.

**tom66** · 01-05-2012, 06:38 PM

Re: Philips 47PFL5704D F7 No Power

If it's the drain it's tied directly to the internal fet, so it's likely the fet died in a spectacular fashion. Causes include a power surge, high temperature, peaking drain voltage (exceeding 700V is okay once or twice... but not too many times) or a chip that was just on it's last legs (e.g. from being operated near it's limits continuously, like in a current limit mode.)

I would expect the mains fuse to blow; check that (including the plug fuse.)

**kolpro** · 01-06-2012, 09:35 AM

Re: Philips 47PFL5704D F7 No Power

Originally posted by retiredcaps

I would check the following for potential shorted components:

- bridge rectifier
- power mosfet
- all diodes in and around U101
- R104 - see if it matches its color band

Good call on ordering 2.

Do I need to check these components out of the circuit or can I check them in place for the short?

**bbjunkie** · 01-06-2012, 09:39 AM

Re: Philips 47PFL5704D F7 No Power

Check in circuit, if any shorts show up then remove and re-test to confirm.

**kolpro** · 01-06-2012, 12:30 PM

Re: Philips 47PFL5704D F7 No Power

Ok I tested for shorts and here are the results so far.

D101--.554
D102---.558
D107--.458
D111---.460
D301--.193
D510--.458
D501--.457
D203--.164
If I test the in opposite direction I get 0 for all D***

R104 -- 196k ohms

tested the Bridge and no shorts it tested good

Please let me know if I'm missing something.

Thanks

**retiredcaps** · 01-06-2012, 02:11 PM

Re: Philips 47PFL5704D F7 No Power

Power mosfet? It usually is a 3 pin IC that is mounted on a heatsink. Measure the resistance between pins 1-2, 1-3, and 2-3.

**PlainBill** · 01-06-2012, 08:15 PM

Re: Philips 47PFL5704D F7 No Power

Originally posted by retiredcaps

Power mosfet? It usually is a 3 pin IC that is mounted on a heatsink. Measure the resistance between pins 1-2, 1-3, and 2-3.

There isn't one. It's been integrated into the FSQ510.

PlainBill

**retiredcaps** · 01-06-2012, 08:25 PM

Re: Philips 47PFL5704D F7 No Power

Originally posted by PlainBill

There isn't one. It's been integrated into the FSQ510.

Ahh, yes, now I remember.

Too many balls in the air today.

**kolpro** · 01-09-2012, 06:49 PM

Re: Philips 47PFL5704D F7 No Power

Ok I installed the FSQ510 chip and still no power to the TV........

**momaka** · 01-09-2012, 09:32 PM

Re: Philips 47PFL5704D F7 No Power

With the FSQ510 chip installed in the circuit, measure the voltage on pin 3 (Vfb), pin 5 (Vcc), and pin 8 (Vstr). Post what voltages you get. Use pin 1 and 2 (GND) as ground or use hot ground (the "-" of the bridge rectifier on the primary).
Try to perform the test fairly quickly (i.e. don't apply power to the TV for too long). This is to prevent anything else from going bad.

**kolpro** · 01-09-2012, 09:59 PM

Re: Philips 47PFL5704D F7 No Power

Here are the readouts.....I used pin 1 as ground

pin 8 -------147 volts
pin 5 ------- 0 volts
pin 3 ------- 0 volts

Thanks again!

I was trying to find a schematic of this board but can not.

**momaka** · 01-09-2012, 11:26 PM

Re: Philips 47PFL5704D F7 No Power

Interesting...
Pin 5 (Vcc) needs to be at least 8.7V in order for the FSQ510 to start and continue to be no less than 6.7V for the FSQ510 to keep operating. Should there be a fault, data sheet says the voltage will fluctuate between 6.7V and 8.7V. The fact that it's not suggests that perhaps Vcc is being pulled low by a shorted component.
The voltage on Pin 3 (Vfb) should also be close to 2.8V when the PSU is operating normally and 4.7V when in overload protection. Getting zero for this one likely means the PSU is not even trying to start.

If possible, post a few more pictures of the PSU - one capturing the underside of the whole board and 1 of the topside again capturing the whole board. The FSQ510 data sheet has a sample circuit on page 2. It looks pretty simple. I think we should be able to figure out the circuit in your PSU without a schematic pretty easily. Just need good pictures.