PHILIPS 42PFL5432D/37 Power Supply troubles

[doityourself]

Originally Posted by PlainBill

Have you had your March blizzard yet? Any bets on how high the water will ride when the snow melts?

The source of your caps is a few hundred miles north of you in Thief River Falls. Here are the Digikey numbers.

1500µF, 35V P14447-ND EEU-FR1V152L $1.43 ea

2200µF, 16V P12369-ND EEU-FM1C222 $1.06 ea

Order by 6:00 PM today, specify USPS First Class Mail shipping, and you should have them on Wednesday, total cost under $10.

PlainBill

hi plainbill !

cool advice on the caps...i have same problem.
just wondering if you have seen where a diode on the back of the board has blown out because of the cap issue? the diode is labled D915, a little one.
a visual inspection with a mag glass looks like it could be popped...
any help would be greatly appreciated!

[markusb92]

I own a 42" Philips LCD TV (42PFL5432D/37) This one acts different then the others. When plugged in lite is red and when i hit the power button it turns green but doesn't turn on... all it does is chirp like a bird and its coming from the power supply, I'm trying to hear where its coming from but cant. Ive read to spray some sort of freeze spray to change the sound and a few other ideas. I replaced the same 4 caps (they were bloated) but still the same thing. (Chirp Chirp Chirp) I searched for a new power supply and found one for 195.00 with a 80.00 core return I'm an amateur, and know how to solder and that's about it. This post has been very helpful if any ideas before i buy a power supply would be very appreciated. I'm not in any rush, already replaced it with a new LED but still think its worth another 115.00 to replace the power supply.

[PlainBill]

A chirping sound usually indicates a power supply isn't starting. Possible faults are an excessive load, or a shorted schottky diode.

PlainBill

[markusb92]

So do you believe that replacing the whole power supply do the trick or would the load be from something after the power supply? Is there a simple way to figure that out? Again thanks for your help.

[PlainBill]

Originally Posted by markusb92

So do you believe that replacing the whole power supply do the trick or would the load be from something after the power supply? Is there a simple way to figure that out? Again thanks for your help.

In general, yes. In this case it may take a little work. The power supply outputs seem to be unlabeled, although none of the pictures are good enough to be certain. Philips usually has good schematics in their service manual, which is available here.

The usual technique I suggest is disconnecting all output cables from the power supply, applying AC voltage to the input, and verifying 5 volts is present at the standby output (5V_SB is one common label). Disconnect AC power, then use a 1k - 3.3K resistor to connect the standby output to the Main power supply control input (PS_ON is a common label) and check the output voltages of the main supply. One difficulty - sometimes the control input turns the main supply off when it is driven high.

If the standby output does not come up, the power supply is defective. If the main supply does not come up (testing both possible states of the control input), the power supply is defective.

PlainBill

[budgies]

Originally Posted by markusb92

I own a 42" Philips LCD TV (42PFL5432D/37) This one acts different then the others. When plugged in lite is red and when i hit the power button it turns green but doesn't turn on... all it does is chirp like a bird and its coming from the power supply, I'm trying to hear where its coming from but cant. Ive read to spray some sort of freeze spray to change the sound and a few other ideas. I replaced the same 4 caps (they were bloated) but still the same thing. (Chirp Chirp Chirp) I searched for a new power supply and found one for 195.00 with a 80.00 core return I'm an amateur, and know how to solder and that's about it. This post has been very helpful if any ideas before i buy a power supply would be very appreciated. I'm not in any rush, already replaced it with a new LED but still think its worth another 115.00 to replace the power supply.

Hi markusb92, and all!!!
Sure enough im having the very same symptoms on same Model... have you had ANY luck just replacing the Power Supply board? Or the Main board?
Thanks, Brad.

[tbuch]

Budgies,

Hi, I am fairly new here also. I have the exact same TV and started out with the issue of no picture/sound and the power light would stay red. I replaced some capacitors (less than $20)and now I am having the chirping issue. Once I get the TV tore back apart, I am going to check some diodes which have caused this issue in another like TV. If this is the issue and I replace these two diodes I will have fixed my TV for right around twenty dollars.

[van18]

Same problem ???magnavox tv ????any luck ?

[tbuch]

Originally Posted by van18

Same problem ???magnavox tv ????any luck ?

Got My Philips up and running today. It has been on for 7 hours no problems at all

[BobbyLeeThomas]

I have the same model with a similar, if not the same, problem. My TV essentially locks up after 5 minutes to an hour. To get it to come back on you have to unplug it. I never got the chirping sound, but I got a high whistle for about 5 minutes and it went away. This all started about two weeks ago and this morning it just stopped. I figured I would see capacitors bulging or leaking. I took it apart and I don't see any swollen capacitors. I have attached pictures. Would you suggest which capacitors I should replace just as a shot in the dark?

[retiredcaps]

Originally Posted by BobbyLeeThomas

My TV essentially locks up after 5 minutes to an hour.

Explain in detail what is "locks up" wrt to

a) backlight
b) picture
c) sound
d) power led

The more detail and info you give, the better our response.

[BobbyLeeThomas]

It started about two weeks ago. The first time I noticed it the TV locked up while I was watching a show. The picture and sound were both still on, but you could not change channels or turn it off. The led light on the power button remained green and blinked when you tried to use the remote, indicating that the TV was picking up the infrared signal from the remote, but nothing changed. Eventually I had to unplug the TV to turn it off. When it was plugged back in, the TV worked correctly, until the next day. The next day the TV would not turn on. The led light on the power button remained red and would not change with the remote or pushing the button. Again, once the TV was unplugged and plugged back in it worked fine. It locked up about twice more while viewing a TV show. Once time we got a low whistling noise. The next day the same symptoms, but more frequent. Every time the TV is turned off, it will not turn back on without being unplugged and plugged in. When it is locked up, the led on the power light can either be green or red. Sometimes the picture is on and sometimes it is off, but now it won't even come on.

[BobbyLeeThomas]

Also, did I post the pictures correctly and are they of the correct quality?

[retiredcaps]

Originally Posted by BobbyLeeThomas

Sometimes the picture is on and sometimes it is off, but now it won't even come on.

Okay, that is a much better description and helps narrow down some possibilities.

1) We will need a picture of the main board. The main board is the one with the hdmi, rca, component cable connectors, etc. Try to get as close to 2000x2000 as possible. Yes, you attached them correctly. Thank you.

2) Do you have a multimeter and are you familiar with how to measure DC voltages?

[BobbyLeeThomas]

Here are some shots of the main board. I have a multimeter and can use it to measure DC (with a little help from the manual).

[retiredcaps]

1) Measure all the pins on the connector between the power and main board. Use a ground screw on the main board for your black probe.

2) List all the DC voltages for all pins when the TV is working and when it is not.

3) Report it like this. Excuse the poor formatting.

Pin Working - Not working
pin 1 - 5V - 0.0V
pin 2 - 3.3V - 3.3V

[BobbyLeeThomas]

retiredcaps,
Will do, one clarification: when you refer to measuring the pins when the tv is not working are you referring to the tv being turned off, or are you referring to when the tv is malfunctioning? Thanks

[Th3_uN1Qu3]

When the TV is on but not working as it should. When the TV is off you'll have only the standby supply running so if that is fine (and it is since it turns on in the first place) there would be nothing to measure.

[BobbyLeeThomas]

Well I have voltage on the pins measured when the tv is working, but now that the tv is lying on the table with its back off it won't malfunction. A little frustrated by this, but I am starting to think that the fact that it won't malfunction while partially tore down might indicate the problem has to do with overheating. I am wondering if there is some other diagnostic step I should take while I wait for the tv to malfunction again?

[retiredcaps]

Originally Posted by BobbyLeeThomas

A little frustrated by this, but I am starting to think that the fact that it won't malfunction while partially tore down might indicate the problem has to do with overheating.

Search is your friend ...

http://www.badcaps.net/forum/showthread.php?t=18277