Philips 47PFL4606 No Power Fuse Keeps Blowing

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

when using an 4.7ohm 9watt pfc and C946 voltage keeps low

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Still i find one thing strange.. when placing the 1K resistor only the 4,6V ramps up to 5V
the PFC 310v and 11,5v keeps at the same level.. when i place board in the tv then the voltage ramps up

You can try force on the power supply board again but this time have a 4.7 (4R7) Ohm 5W (10W preferred, since 5W will be at the limit) connected to 5VSTBY output and the see if the C946 Voltage will go to 14 ~ 15V when using force on and the PFC will stay on or not.

So far we get the two 47" boards, one 37", and one Stereo receiver (bad brown out resistors) fixed, now you only have the 46" one to deal with.

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Still i find one thing strange.. when placing the 1K resistor only the 4,6V ramps up to 5V
the PFC 310v and 11,5v keeps at the same level.. when i place board in the tv then the voltage ramps up

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Look like Q906 is defective.. after replacing that one iam getting 4.6V and 5V with an 1K

So this 47" board is working now with all the parts back in place?

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Look like Q906 is defective.. after replacing that one iam getting 4.6V and 5V with an 1K

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

So i need to check this section on fault ?

Yes, that is the section that we removed some parts to deactivate the Brown out protection, so make sure you put all the correct parts back in to the right location correctly, and since you have working 37" board now so you can use that board to compare that the parts are correct and at the same locations.

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

So i need to check this section on fault ?

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Yes that is correct !

OK, let me look into the Brown out circuit section then.
BTW, you should look at the parts of 37" board brown out section and compare the parts of the brown out section of the 47" we removed earlier to make sure the same parts are put back into the 47" board.

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Yes that is correct !

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

So the 37" board is now working: https://www.badcaps.net/forum/showth...460#post982460

Now we just need to find out what is going on with this 47" board.

So right now C946 Voltage and C907 PFC Voltages are correct and they stay working , but when you put the parts for Brown out shutdown circuit back in place, the power supply stops working again and no 5V standby, correct?

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

oke what can i check to find out what is the issue

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Still wonder we removed R966 and Q906 so the brownout is not working, How iam able te restore that function. Because when i solder these back 5V is gone again

The brownout protection is for shutting down the power supply of the Brown out protection circuit detects low incoming AC. I had you remove it to make sure it is not shutting down the power supply because if protection circuit is faulty thinking that the AC is low when it is not so it shutdown the power supply.
So when you put the brown out protection back in place, the circuit shutdowns the power supply even though the incoming AC is not low (180 VAC is typical brown out condition), that means we will have to troubleshoot the brown out protection once we fix the original problem first.

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Still wonder we removed R966 and Q906 so the brownout is not working, How iam able te restore that function. Because when i solder these back 5V is gone again

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

i placed back the 18,7K without the 820K,
The set still makes that hissing sound when powering on even when the broken CCFL removed

You are probably hear the high Voltage arcing, the backlights circuit should have gone into shutdown since it will detect open lamp (lamp not connected) condition.

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

i placed back the 18,7K without the 820K,
The set still makes that hissing sound when powering on even when the broken CCFL removed

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

I think i found the problem.. there where 2 CCFL tubes broken, And while re-arranging them i broke an other one.
Can i source those tubes some where ?

I have no Idea where you can buy the CCFL in your country, you may have to source them from China.

I wonder what causes the startup Voltage on C946 (same on the37" board that just read) to be normal again.
So you only put in just 18K7 in place without 820K in parallel?

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

I think i found the problem.. there where 2 CCFL tubes broken, And while re-arranging them i broke an other one.
Can i source those tubes some where ?

[trunks81]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

What i find strange when i connect the board back in the tv iam getting 11.5V on C946

Edit did some more testing.. and now ive got PFC and IC startup voltage ?? Dont ask why?
So i made an file with PFC voltage with the 20K resistor which went up to 375V
that to low so i made the decision to put back the 18.7K and the PFC went back up to 400V

EDit tv boots up now only BL trafo is making an high pitch noise and then the protection mode comes in
When i do not connect the BL tv boots like normal

Edit the brownout is still not good when soldering in R966 and Q908 board does notting again

[dick_barton]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

There may be an issue with the replacement FAN chip. Earlier on in one of the threads the comment was that when replaced the power supply worked but only until it was switched off.

[budm]

Re: Philips 47PFL4606 No Power Fuse Keeps Blowing

Now the big question is how can we get the 9.9v back up to 15v

That is the problem, we never figure out as to why the Voltage will not go up as high as the other 47" board we fixed.