Philips 32PFL5322D/37 power supply repair

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

I'm back, no success.

I was able to get the old controller off, it was definitely shorted. The new one read much higher resistances on all the pins (100s of ohms). With the new controller installed, I still don't have voltage on the standby pins.

I'm not sure where to go from here. Any suggestions?

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

Refer to figure 3 for the pinouts.



1) What is the DC voltage on pin 2 (Vcc)? Use pin 3 for ground. Is it steady or fluctuating?

Be careful not to let the probes slip and short anything out.

2) What is the DC voltage on pin 14 (drain)? Warning, this could be very high voltage here. It should be at least 165V DC with a chance of it being > 330V if PFC is involved.

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

Vcc -> Ground I have 0.5 v, holding steady. For measuring drain, do I still use pin 3 for the ground?

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

Vcc -> Ground I have 0.5 v, holding steady.

Hmm, not good. The SMPS controller needs at least 10.5V, 11V being typical to startup.

What is the DC voltage across the following 2 caps? Black probe on negative, and red probe on positive.

C036 and C130. I *think* one of them is the startup cap.

For measuring drain, do I still use pin 3 for the ground?

Yes.

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

Drain is 0.7v, c036 has 0v, and c130 has -0.5v.

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

What is the DC voltage across the big cap (450V 120uF)? It is working properly, it should be at least 165V DC. 120V AC mains x 1.414 is roughly 170V DC.

Note the heatsinks are live too (thus the big red warning stickers).

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

The big cap reads 166v.

I'm off to bed, but I will be online tomorrow and can do some more tests. Maybe a solution will come to me in my sleep.

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

The big cap reads 166v.

Okay, that is good.

It is hard to tell, but I'm looking for your power mosfet. It is usually a 3 pin IC. It might be the IC just left of L066 mounted on the heatsink that says Danger?

The way to verify is look at the part number and find its datasheet. The datasheet will say something like power mosfet. If that is the correct part, test it for shorts between pins 1-2, 1-3, and 2-3. Any reading under 30 ohms suggests it may be shorted and you have to desolder to verify.

If that is not the power mosfet, check all the ICs mounted on the heatsink marked "Danger".

I'm also not the best schematic reader, but page 16, figure 11 suggests on the datasheet that there are no components between pin 14 and the primary winding transformer. It is rare for the transformer to go bad and you have a new SMPS chip. Now your TV might actually have some components in between like a resistor that might be open. I'll try to find the TV schematic and see.

It is possible that the power mosfet is shorted and it took out the SMPS controller with it.

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

1) Well, I found the service manual and skimmed quickly through it twice, but I cannot find a schematic for the power board?

http://www.scribd.com/doc/46693741/32PFL5322D

2) Maybe I missed it, but there are not hits for "1533" anywhere.

3) On the top heatsink marked "Danger" what is that big IC mounted on the heatsink? Maybe that is the power mosfet?

4) On the back of the power board, there are two 16 pin ICs. One is the TEA1533. What is the other part number?

5) Also can we get a close up picture of the new TEA1533 installed?

6) Can you also identify/point out where TEA1533 is on the back?

7) What is the part number for T102?

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

Okay, that is good.

It is hard to tell, but I'm looking for your power mosfet. It is usually a 3 pin IC. It might be the IC just left of L066 mounted on the heatsink that says Danger?

The way to verify is look at the part number and find its datasheet. The datasheet will say something like power mosfet. If that is the correct part, test it for shorts between pins 1-2, 1-3, and 2-3. Any reading under 30 ohms suggests it may be shorted and you have to desolder to verify.

Yes, that is the power mosfet, I put the number into google, P20NM50FP, and the first result was a datasheet listing it as such.

Unfortunately, it is not shorted. I checked the pins in diode test mode. One direction read OL, and the other between 500 and 700 ohms depending on the leg.

I'm also not the best schematic reader, but page 16, figure 11 suggests on the datasheet that there are no components between pin 14 and the primary winding transformer. It is rare for the transformer to go bad and you have a new SMPS chip. Now your TV might actually have some components in between like a resistor that might be open. I'll try to find the TV schematic and see.

It is possible that the power mosfet is shorted and it took out the SMPS controller with it.

I agree on the schematic in the datasheet that nothing is between the drain and the transformer. On my board, there is a resistor which reads 650 ohms (the 'patch' resistor that was discussed on page 1).

1) Well, I found the service manual and skimmed quickly through it twice, but I cannot find a schematic for the power board?

http://www.scribd.com/doc/46693741/32PFL5322D

2) Maybe I missed it, but there are not hits for "1533" anywhere.

I have that page bookmarked, I didn't see a power board schematic either. And you can't search it, for some reason it is an image.

3) On the top heatsink marked "Danger" what is that big IC mounted on the heatsink? Maybe that is the power mosfet?

One heatsink has a power mosfet on it (P20NM50FP), and the other has the bridge rectifier. The part number on it is GBU606, and it looks like it is a replacement part.

4) On the back of the power board, there are two 16 pin ICs. One is the TEA1533. What is the other part number?

TEA1601T

5) Also can we get a close up picture of the new TEA1533 installed?

See attachment, I used my camera phone. It's my first SMD soldering attempt, so it may not be the best.

6) Can you also identify/point out where TEA1533 is on the back?

See attachment, it is circled in white.

7) What is the part number for T102?

F3NK80Z. I replaced it before I posted on the forum, as it appeared to be blown open. But when I got the new one it performed exactly the same as the old, but I installed the new one anyway.

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

I agree on the schematic in the datasheet that nothing is between the drain and the transformer. On my board, there is a resistor which reads 650 ohms (the 'patch' resistor that was discussed on page 1).

Hmm, humor me for one test here.

1) Put your black probe on the negative leg of the big capacitor (450V 120uF) for ground. Again, be careful with high voltage here on the hot side.

2) Put your red probe on the red circled dot of the patch resistor. What is the DC voltage?

3) Put your red probe on the blue circled dot of the patch resistor. What is the DC voltage?

4) With power off and TV unplugged, where does the blue circled dot connect to on TEA1533? That is, which pin has continuity to the blue dot?

5) Please confirm that patch resistor was installed by the seller and not you.

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

Hmm, humor me for one test here.

1) Put your black probe on the negative leg of the big capacitor (450V 120uF) for ground. Again, be careful with high voltage here on the hot side.

2) Put your red probe on the red circled dot of the patch resistor. What is the DC voltage?

3) Put your red probe on the blue circled dot of the patch resistor. What is the DC voltage?

4) With power off and TV unplugged, where does the blue circled dot connect to on TEA1533? That is, which pin has continuity to the blue dot?

5) Please confirm that patch resistor was installed by the seller and not you.

On both the red dot and the blue dot, the voltage is 0.16v.

The blue dot connects to the drain of the TEA1533AT, or pin 14. I did not detect any solder bridges.

The patch resistor was installed by the seller. On the top of the board where the resistor originally ran, you can see a burn mark. Looks like the whatever happened burned up the original resistor pretty good.

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

On the top of the board where the resistor originally ran, you can see a burn mark.

Can we get a close up picture of that?

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

1) Can you doublecheck if there are any other components that are in between the big cap (450V) and pin 14 other than the patch resistor?

2) Does the positive leg of the bag cap have continuity to the red circled dot on the patch resistor?

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

There are quite a few components between the big cap and the drain. I also have open circuit between the positive on the cap and the patch resistor (both sides)

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

There are quite a few components between the big cap and the drain. I also have open circuit between the positive on the cap and the patch resistor (both sides)

1) Do the pads of R112 have any continuty to the big cap?

2) If the patch resistor is really R112, I wonder if you should desolder it from the backside and put it back on the front side properly?

3) I hope you see what I'm trying to do here. From the big cap, we have 166V DC and somehow it is disappers before it reaches the red dot on the patch resistor.

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

1) Do the pads of R112 have any continuty to the big cap?

2) If the patch resistor is really R112, I wonder if you should desolder it from the backside and put it back on the front side properly?

3) I hope you see what I'm trying to do here. From the big cap, we have 166V DC and somehow it is disappers before it reaches the red dot on the patch resistor.

1) No.

2) Judging by the looks of the resistor, the leads were too short to fit across the span between the pads, so it was added to the bottom. I may go buy a new one with longer leads so it will be in the right place.

3) I do see what you are trying to do here. I started tracing with my meter, starting at the big cap. Power is not applied, just using diode test mode. I made it not very far and I encountered a glob of glue. After picking some of it away with my fingernail, I found a lead under it. Wouldn't you know, it is connected to the main cap! Looking around, I found it is actually R100, which can be seen in my overall picture. I put my meter across R100, and bingo! Open circuit. I even cranked it up to the 20 megaohm range, and still open circuit. Looks like an open resistor!

Now my problem is: I have never seen a resistor with this sort of color scheme on it. It has Brown-Black-Gold-Gold-Violet.

[retiredcaps]

Re: Philips 32PFL5322D/37 power supply repair

Now my problem is: I have never seen a resistor with this sort of color scheme on it. It has Brown-Black-Gold-Gold-Violet.

Post a close up picture so we can see it.

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

Post a close up picture so we can see it.

See attached.

[rpgruss]

Re: Philips 32PFL5322D/37 power supply repair

I should add, that when I start on the other side of R100 and continue my journey towards the patch resistor, everything is connected (as it appears it should per the conversation in this thread). R100 goes to L100 (inductor?), which is connected to the primary side of the transformer, and then to the patch resistor, and finally the drain of the TEA1533 controller.