Philips PLCD190P5 power supply

[The Performer]

Hello all, been a long time and am hoping for advice on an lcd philips 32" tv repair. The model number is a 32PFL5332D/37. As far as I have found (from the net and this forum is no luck with a schematic for the actual PS board.)

I got the tv not working and immediately dove into the back to check the powersupply. So far I have found (4x) burnt 6.8G ohm resistors that are in parallel of each other, and near another resistor that is completely burnt so much that It is impossible to make out the color bands. I have found (1x) P20NM50FP N-channel mosfet near the burnt resistors that reads Shorted (31 ohm gate -drain and 2ohm Drain-source) and found a PFC controller L6562 that shows low resistance between 1, 2, and 3 pins (I will most likely like to replace since it is a cheap assurance) I will attach a few pictures of the board, and I have found a few pictures from other members that show the burnt resistor in question, however I simply cannot make out the colors myself.

The resistor I do not know is R064 and it is below the negative band of the biggest electrolytic capacitor on the board. It reads .851k if I measure it with my meter while in circuit. My question to the pro's is, what would you do in this scenario and is there any other things I should test/ consider. I am willing to spend a few bucks and order the parts from digikey I have already found suitable parts for the ones I can identify and can order them to try, but the one burnt resistor is throwing me for a spin.

Also I attached the best photo I could find online that shows the resistor but I cannot make out the colors.

If anyone can offer any assistance I would much appreciate it.

[R_J]

Re: Philips PLCD190P5 power supply

Remove one end of R064 and measure it, It does'nt look burnt in the picture, this plcd150p1 looks similar
The plcd300p3 schematic uses a 330 ohm

[The Performer]

Re: Philips PLCD190P5 power supply

Remove one end of R064 and measure it, It does'nt look burnt in the picture, this plcd150p1 looks similar
The plcd300p3 schematic uses a 330 ohm

Thank you for the response R_J, removed from circuit the resistor reads .983k ohm. It is definately burnt to a crisp, removed and close up if it had a color code band it would be black with no tolerance band.

What are you seeing that makes you see this board and that schematic similar?

[Andrew F. Ali]

Re: Philips PLCD190P5 power supply

Thank you for the response R_J, removed from circuit the resistor reads .983k ohm. It is definately burnt to a crisp, removed and close up if it had a color code band it would be black with no tolerance band.

What are you seeing that makes you see this board and that schematic similar?

A resistor reading 0.983k Ohms=983 Ohms. Unless it was suppose to be 1.0 Ohm, I would say that is OK. I would probably temporarily try a 1k Ohm in its place.

[R_J]

Re: Philips PLCD190P5 power supply

In the plcd190p1 (schematic) they use the same pfc ic. I suspect the resistor (3064) is the one connected to the CS pin of the ic, and to the source resistors of the fet. this resistor is 0E (0 ohms) for the plcd190p1.
In the plcd300p3 they use a 330 ohm. so I can't be sure. here is the shopjimmy picture but it is hard to tell the value

[CapLeaker]

Re: Philips PLCD190P5 power supply

probably R064 is open when you measure it out of circuit.

[The Performer]

Re: Philips PLCD190P5 power supply

probably R064 is open when you measure it out of circuit.

So I removed it from circuit and that's when it measures .983k ohm, in circuit it was .851k.

So as the others suggest would it hurt if I use a 1k ?

[CapLeaker]

Re: Philips PLCD190P5 power supply

Well, put it this way, if a resistor fails, it goes higher in ohm value. I did have a look at the board from SJ and I couldn't identify one color ring. So I got either 1k ohm or 100M. So I'd start with the 1k ohm resistor.

[The Performer]

Re: Philips PLCD190P5 power supply

Well, put it this way, if a resistor fails, it goes higher in ohm value. I did have a look at the board from SJ and I couldn't identify one color ring. So I got either 1k ohm or 100M. So I'd start with the 1k ohm resistor.

Sold american.

Parts are on order, updates as soon as they arrive.

[R_J]

Re: Philips PLCD190P5 power supply

Most of the circuits using that L6562 ic either connect it directly to the fets source resistor or use between 10 ohm and 1K.

[The Performer]

Re: Philips PLCD190P5 power supply

Most of the circuits using that L6562 ic either connect it directly to the fets source resistor or use between 10 ohm and 1K.

Ok I guess that makes some sense. Can anyone tell me what is up with the 4 resistors all running in parallel? They are 6.8g Ohm. Did they just need a 1.7g ohm value and that is the only way to get it? Im not used to seeing that.

[R_J]

Re: Philips PLCD190P5 power supply

It is not a "G" ohm, that would be 6.8 gigaohm. Just 6.8Ω
they use 4 resistors to spread the current instead of one large resistor. They are 6.8 Ω. it can also be used to fine tune the current through the fet by changing one or more of the resistors for different size tv's

[The Performer]

Re: Philips PLCD190P5 power supply

It is not a "G" ohm, that would be 6.8 gigaohm. Just 6.8Ω
they use 4 resistors to spread the current instead of one large resistor. They are 6.8 Ω. it can also be used to fine tune the current through the fet by changing one or more of the resistors for different size tv's

R_J, I Have now looked closer at the resistors and it looks like I was wrong, the colors are blue, grey, silver, gold... So .68 ohm... The funny thing is the parts I ordered, the resistors that I thought I ordered 6.8 gigaohms ended up being 6.8 ohm... So even though the order was wrong, Im still wrong again...

I was reading the colors as blue, grey, grey, gold, and putting it into my electrodroid app.

Now what do I do... haha.

[R_J]

Re: Philips PLCD190P5 power supply

Get some .68 Ω resistors...

[The Performer]

Re: Philips PLCD190P5 power supply

Get some .68 Ω resistors...

What is the odds that I can use 1x .1 ohm resistor? If im understanding correctly, the 4x .68ohms in parallel have a total of .17 ohms?

Could i use a single .1ohm to do testing while I order 4x .68 ohms or am I wrong assuming this will work?

[The Performer]

Re: Philips PLCD190P5 power supply

So as an update, i have installed a temporary .1 resistor to do some testing and upon powering up the board both in and out of tv I get 5v output and no 12v output. With these power supplies do I need to short standby pins or anything to get the supply to power on? There's no schematic for the PS board to be found, the only thing I have to go off of is the service manual shows the pinouts of the connector that comes from the ps board. I've attached a screenshot below.

[budm]

Re: Philips PLCD190P5 power supply

Some of the Philips power supply use Active low (PS-ON to GND = ON) to turn on the rest of the power supply, some is ACTIVE HIGH (PS-ON > 2VDC = ON, <1V = OFF).
You need to test the power supply board by itself but using 100 Ohms resistor between GND and the PS-ON (STBY) pin of the power supply to see if the rest of the power supply will come on or not, if not, then use 1K resistor between standby 5V and the PS-ON to see if the rest of the power supply will come on or not.

[R_J]

Re: Philips PLCD190P5 power supply

Did you have 5 volts standby before the repair? If it is the standby section that was repaired, then you should be able to connect the main and it should turn on the 12 volts, I believe pin 11 is the standby ON pin to turn on the rest of the power supply, check this pin to see what the voltage is.

[The Performer]

Re: Philips PLCD190P5 power supply

Some of the Philips power supply use Active low (PS-ON to GND = ON) to turn on the rest of the power supply, some is ACTIVE HIGH (PS-ON > 2VDC = ON, <1V = OFF).
You need to test the power supply board by itself but using 100 Ohms resistor between GND and the PS-ON (STBY) pin of the power supply to see if the rest of the power supply will come on or not, if not, then use 1K resistor between standby 5V and the PS-ON to see if the rest of the power supply will come on or not.

Thank you for the response sir! Doing both of those tests did not turn on the 12v output...

[The Performer]

Re: Philips PLCD190P5 power supply

Did you have 5 volts standby before the repair? If it is the standby section that was repaired, then you should be able to connect the main and it should turn on the 12 volts, I believe pin 11 is the standby ON pin to turn on the rest of the power supply, check this pin to see what the voltage is.

Thank you for the response R_J, I verified that pin 11 does indeed show 5.1v at rest.

To answer your first question, I do not know if the 5v was present before I replaced any parts, I was given the set by my brother and went from his word that nothing was powering on. I immediately pulled the supply and started visual inspection. Saw the handful of resistors completely burnt, and began meter checking near by obvious mosfets and drive controllers that might be shorted. Not until after I replaced the found bad parts have I powered it on.

I am using a 25w incandescent light bulb as a current limiter while testing and immediately plugging it it the filament glows VERY dim quickly then goes off and little to no current is flowing.

Im having fun trying to learn more but have gotten myself at a roadblock, not familiar with this power supply function and obvious fixes.