Philips LCD 42PFL5432D/37 - Bad PSU

[patdude72]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Hi folks I am brand new to this forum and what brought me here is an issue with my 42 inch lcd phillips tv, 42PFL5432D/37 picture is out and it makes chirping sounds, i briefly looked at a few posts on this thread, and from what I gather it could be as simple as replacing some caps. I am wondering if it is as simple as that, or am I wasting my time, as I am about to start taking the tv apart. I would like to take a shot a fixing this tv myself any help or feedback would be appreciated

[bbjunkie]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Happy new year M1SCH1EFMAYHEM

To quote a regular here (retiredcaps) :

Capacitors (C designation on the PCB board) die from age, heat, and shoddy build quality. Capacitors DO NOT have to be visibly bloated in order to bad. They can be out of tolerance uF (a 1000uF measures 20uF) and/or have high ESR (ohm). A multimeter will be insufficient to test for ESR. For that you need an ESR tester which costs between $50 and $300.

It would probably be easier if you started a new thread with some photos first (at least a good quality well illuminated top down shot of the power supply board) preferably as close to 2000x2000 as possible.

Attach the photo with the "manage attachments" button which is below the submit reply button in the "Additional Options" box

If you have the facilities for measuring ESR and are confident in doing so, then by all means go ahead and check the caps.

Otherwise, post the photo and someone will be along to point you in the right direction

Jim

[M1SCH1EFMAYHEM]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Happy New Years!!

I have been reading all the post and I also have this Television. When i plug in the power cord the red light blinks 6 times. When i opened up the cover everything looked fine. I did not see any burn marks or bulging caps.

This is the Board i have at.
http://assets.shopjimmy.com/media/ca...42724421_7.jpg

I am considering replacing the caps, but since they don't look like they are bulging should I?

Thank you

[momaka]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

According to the pics on page 1 and 2 of this thread, the negative side of each cap (the side marked with a stripe) should be aligned with the shaded semi-circle on the board.

[Dgtech]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

OOPS!!! Replace all of them again and pay attention to the markings on the board underneath. Sometimes it will be a circle with one half of it bolder than the other half indicating the negative side. Sometimes they will just print a negative sign on the board itself.

[Tscott]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

I'm experiencing the same issue with my 42" and ordered the 4 caps that were needed. (3 of the original caps were bulged) Reassembled the unit and plugged it in. Red light came on solid.....flashed a few times and then just remained solid red and would not turn on any further. After dis-assembling again, found that the one 2200 cap had bulged already. Do these caps have a polarity that determines which direction they need to be installed? I should have payed attention better during install but it was family game night and my kids were telling me it's my turn.

Thanks!

[erwhat]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

I had the same issue with my 42" phillips. With the information found in this thread, I replaced the bulging caps and the 2 diodes (that were burned out), works perfectly now!
Thanks everybody!

[PlainBill]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Will do. The replacement PSU I bought last year has already blown it's caps. The same Capxon caps as the original. When I get around to replacing it, I'll come back with pics.

It's pretty funny, last year when I started this thread, there was little info to be found on this "lemon" TV. Now, just this site alone has numerous posts about it's problems. Get the word out to friends and relatives to NOT buy this TV.

A little late for that. Philips last shipped the TV in October, 2008.

PlainBill

[Lobo]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

If I am looking for burn marks or some disfigured component, I dont see how nuclear's pics are gonna help me. That is, of course, unless Trixter bought the set from nuclear. Each person should post pics of their TV due to the many different revisions of each board, or tv.

Please post a picture of YOUR whole set opened up and one of each board inside.

Will do. The replacement PSU I bought last year has already blown it's caps. The same Capxon caps as the original. When I get around to replacing it, I'll come back with pics.

It's pretty funny, last year when I started this thread, there was little info to be found on this "lemon" TV. Now, just this site alone has numerous posts about it's problems. Get the word out to friends and relatives to NOT buy this TV.

[Dgtech]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

If I am looking for burn marks or some disfigured component, I dont see how nuclear's pics are gonna help me. That is, of course, unless Trixter bought the set from nuclear. Each person should post pics of their TV due to the many different revisions of each board, or tv.

Please post a picture of YOUR whole set opened up and one of each board inside.

[momaka]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

There was never a whole clear picture posted of the original board (top and bottom).

Nuclear posted some decent pictures on page 2 (though I will admit they are a bit fragmented). These are the two posts:
https://www.badcaps.net/forum/showpo...5&postcount=31
https://www.badcaps.net/forum/showpo...4&postcount=38
and schematic can be found here:
https://www.badcaps.net/forum/showpo...6&postcount=71

Well my board is still in the same situation. Seems no one has been able to fix this chirping issue.

I just looked back at your previous posts in this thread. You said you have recapped the PSU, but what brand and series of capacitors did you use? Did you also replace the small caps?
Other than that, clear, well-focused pictures of your boards would be helpful. Sure we already do have pictures and a schematic from other members, but sometimes there may be slight differences in the PSUs.

[Dgtech]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Working on the same case. Just opened the tv and the caps on psu were buldging. Same values as the ones posted in first thread. Once caps A,B,C, and D come in, I'll solder them in and see results. The tv is now doing that chirping sound with no screen. I've fixed quit a few things in my time. Hopefully I'll add this on to the list.

I always like to think to go back to the original problem. The caps were found to be bulged. It's hard for me to beleive that there are two separate problems. There may be a problem caused by the first, sure. There was never a whole clear picture posted of the original board (top and bottom). This is the one where the diode was changed as well as the caps. If you can do so, we can work from there.

By the way, I think someone either shipped you the wrong replacement board or a non working board. You may be injecting another problem altogether into the set. Board swapping is ok as long as you know the other board works.

[trixter]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

OMG. Didn't know this thread came back. Well last time I posted, no one said anything for a long time so I stopped coming back here. Looks like a lot more good info. Well my board is still in the same situation. Seems no one has been able to fix this chirping issue. Looks mostly like you guys have been trying to do this external power mod instead of fixing the real issue. I recived another power supply that was suppose to work, but when it is put in nothing happends. The red power light on the power button is flickering rapidly. Doesn't power on. Also this board doesn't chirp. I've swapped parts back and forth on each board, but they both get the same results. Not sure what to do now except keep changing parts.

[PlainBill]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Hey guys,

My Philips 48" t.v. went out Monday (3 days ago). I searched all over google for "my philips t.v. keeps turning off" and etc. And I found your great forums here. I did some searching through this thread. Through this one and other posts on your forums I was able to find all the information I needed. I'm a network technician, but know nothing about other electronics and how they work as far as t.v.'s and etc. go.

Through reading your forum posts: I was able to get my t.v. up and running via over-night shipping my new caps, and soldering them in place of the old ones... My t.v. works GREAT now!

I just wanted to visit this site and thank all of you guys for providing such an informative and helpful forum here. I ended up fixing my t.v. for $9.00! My t.v. is the same model/kind as the one here: 42PFL5432D/37. Seems like a common problem with this model. Everything else about this t.v. is great though, for it's price.

Again: thank you all for your informative posts!

Thanks for the kind words; there is only one problem. A 42PFL5432D/37 is a 42" TV, not 48".

PlainBill

[revenger681]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Hey guys,

My Philips 48" t.v. went out Monday (3 days ago). I searched all over google for "my philips t.v. keeps turning off" and etc. And I found your great forums here. I did some searching through this thread. Through this one and other posts on your forums I was able to find all the information I needed. I'm a network technician, but know nothing about other electronics and how they work as far as t.v.'s and etc. go.

Through reading your forum posts: I was able to get my t.v. up and running via over-night shipping my new caps, and soldering them in place of the old ones... My t.v. works GREAT now!

I just wanted to visit this site and thank all of you guys for providing such an informative and helpful forum here. I ended up fixing my t.v. for $9.00! My t.v. is the same model/kind as the one here: 42PFL5432D/37. Seems like a common problem with this model. Everything else about this t.v. is great though, for it's price.

Again: thank you all for your informative posts!

[momaka]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

The 1500uF is CapXon GF series

In that case, proper replacements would be any of the following:
United Chemicon KZE, Nichicon HD, Panasonic FM, and Rubycon ZL.

If you can't find these caps 25v, 1500uF for those series, try United Chemicon KY, Nichicon HE, and Panasonic FR.
Technically, they are not as good as the CapXon GF, but they are very close, and still way much better than the Radio Shack capacitors.

Most of these can be found at digikey.com and mouser.com. I checked the BCN store, but there are no 25v caps with 1500uF capacitance, unfortunately.

I would give it a try, but I don't want to get my hopes up. I'm not even sure if the original caps were ruined in the first place, and like I mentioned before the chirping sound was coming from the transformer (T904).

Right. But chirping is also somewhat common when a power supply cannot start due to a bad start-up capacitor, and the chirping in those cases also comes from the transformer.

Besides, CapXon doesn't have a really good reputation around here. Most people usually just replace them on sight, especially in LCD TVs and monitors, because they are known to fail over time (they don't last in hot places at all).

Nope, I haven't thrown anyway anything.

Excellent! Keep them. When you get the new caps, install everything the way it was originally.

Yeah, I would still replace those RadioShack Caps with something else. I was just trying to fix that PSU in one day and RadioShack is the only place to get things local. Those caps weren't all that cheap though about $5-$6 dollars a piece, but that is RadioShack for you.

Ouch, that is quite expensive for a capacitor. Good quality, low ESR capacitors usually cost under $1 each (and only around $10 for the whole order + shipping).
The Radio Shack capacitors cannot stay because it's very likely that they are not filtering noise and ripple very well right now, and this may damage other capacitors and components in the TV over time.

In addition to that, also replace C957 (10uF, 25v - this is the standby supply startup capacitor - very important), C958 (47uF, 25v), C955 (2200uF, 16v - this is the standby output filter capacitor, also important), and C921 (100uF, 25v).

For C957, C958, and C921, you may also use any of the following caps in addition to the caps I listed above:
United Chemicon LXY and LXZ, Nichicon PW and PM, and Panasonic FC.

Let me know if you need more help finding the replacements.

I didn't necessarily mean to combine it all into one, I was thinking of using just one power supply to piggy back the TV's power supply, rather than having two.

Should be possible. I can think of a few ways, but they are pretty complex. Changing the capacitors is still easier.

[Xeniczone]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

No need to apologize here. Two years ago, I knew very little electronics as well.
Transformers are pretty simple actually. Think of it as two or more coils (or windings) wound on a piece of iron. Wherever you input an AC voltage on one of the coils, you will get an AC output voltage on the other coils. The size of the output voltage of each coil is proportional to the number of turns on that coil to the number of turns on the coil you're inputting the voltage.
Say we have an ideal transformer with two windings - one with 100 turns and another with 10 turns. If you put 200 VAC on the 100-turn winding, you will get 20 VAC on the 10-turn winding ( [200 * 10]/100] ). If you put 5 VAC on the 100-turn winding, you get 0.5 VAC on the 10-turn winding. And so on...
The winding on which you input the AC voltage is called primary, whereas the winding on which you get an output is called secondary. Then you can use the following formula to calculate the voltages on a transformer:
V1 * N2 = V2 * N1
where V1 and V2 are the voltages on the primary and secondary windings respectively, and N2 and N1 are the number of turns on the secondary and primary windings, respectively.
Also, transformers work only with AC voltages, and not DC.
That's pretty much all of the basics on transformers. Not like you need to know any of that for the PSU mod, though.

O yeah, I knew all that. I just didn't understand the concept of an aux. coil or how one coil (in this case on the primary side) can have 4 connectors.

Well, I don't mean to rain on your sunshine here, but Radio Shack capacitors are not very suitable for this application and will need to be replaced with something better.

There's two other very important parameters besides the capacitance and voltage rating of each cap. Those two parameters are ESR (equivalent series resistance) and Ripple Current handling capability (or just Ripple Current).

Now that I didn't know. Good information, thanks!

With that said, what were the original capacitors on your PSU (brand and model)?

The 1500uF is CapXon GF series

Did a little research and found the datasheet that lists the Ripple Current and the impedance.

This also raises the doubt - what if your power supply is working fine but you concluded that it's not because you used inadequate Radio Shack capacitors? In this case, you may be just $10 or so away from a perfectly working power supply again without all of those external power supplies.
I would certainly give it a try. Hope you haven't thrown away any of the removed parts yet.

I would give it a try, but I don't want to get my hopes up. I'm not even sure if the original caps were ruined in the first place, and like I mentioned before the chirping sound was coming from the transformer (T904). I know this because I used a microphone and stuck it on each component in the area to measure the loudest sound, aka where the chirping was coming from.

Nope, I haven't thrown anyway anything.

Oh nice, you got it working!
(lol you fixed it faster than I could type my post ).

Well, I would still encourage a complete recap - maybe we can get your PSU running properly with good caps and no external power supplies again.
(and if not, you can always keep it the way it is, now that you know that it works).

Yeah, I would still replace those RadioShack Caps with something else. I was just trying to fix that PSU in one day and RadioShack is the only place to get things local. Those caps weren't all that cheap though about $5-$6 dollars a piece, but that is RadioShack for you.

As for integrating the PSUs into one - I do have a few ideas, but they may or may not work, and now that you have a working power supply, I'm not willing to suggest them that much, just in case they don't work (but I will if you really really want to).

I didn't necessarily mean to combine it all into one, I was thinking of using just one power supply to piggy back the TV's power supply, rather than having two.

[momaka]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Ahh, okay may bad. Again, I apologize, I should know more about transformers, but I never learned anything about them in school and never did any research online about them. I need to find me a good book.

No need to apologize here. Two years ago, I knew very little electronics as well.
Transformers are pretty simple actually. Think of it as two or more coils (or windings) wound on a piece of iron. Wherever you input an AC voltage on one of the coils, you will get an AC output voltage on the other coils. The size of the output voltage of each coil is proportional to the number of turns on that coil to the number of turns on the coil you're inputting the voltage.
Say we have an ideal transformer with two windings - one with 100 turns and another with 10 turns. If you put 200 VAC on the 100-turn winding, you will get 20 VAC on the 10-turn winding ( [200 * 10]/100] ). If you put 5 VAC on the 100-turn winding, you get 0.5 VAC on the 10-turn winding. And so on...
The winding on which you input the AC voltage is called primary, whereas the winding on which you get an output is called secondary. Then you can use the following formula to calculate the voltages on a transformer:
V1 * N2 = V2 * N1
where V1 and V2 are the voltages on the primary and secondary windings respectively, and N2 and N1 are the number of turns on the secondary and primary windings, respectively.
Also, transformers work only with AC voltages, and not DC.
That's pretty much all of the basics on transformers. Not like you need to know any of that for the PSU mod, though.

Is the Aux winding just a 1:1 winding or something like that?

Most likely not. But we don't really need to know, anyways .

They are ones I bought at radio shack, so I'm not sure of the actual branding or anything because I'm sure radio shack just buys them and places their logo on the them.

Well, I don't mean to rain on your sunshine here, but Radio Shack capacitors are not very suitable for this application and will need to be replaced with something better.

There's two other very important parameters besides the capacitance and voltage rating of each cap. Those two parameters are ESR (equivalent series resistance) and Ripple Current handling capability (or just Ripple Current).

In almost all modern switch mode power supplies (like the one in this TV), the AC voltage fed to the transformer is switched at relatively high frequencies (40 KHZ to 120 KHz or even more). When the output voltage from the transformer is rectified (turned into DC), there are undesirable high frequency voltage spikes and dips (called ripple and noise). The ripple and noise needs to be filtered out, and this is where the electrolytic capacitors come in: basically, the electrolytic capacitors function like little batteries, charging quickly when there are voltage spikes (thus suppressing the voltage spikes) and discharging when there are voltage dips. This makes the output DC voltage much smoother.

Unfortunately, like everything else, capacitors are not perfect and they have an internal resistance called ESR. At high frequencies, the ESR starts to become an issue because it doesn't allow the capacitor to charge/discharge as quickly as it should. Therefore, the capacitor is not able to filter out all of the noise and ripple.

And this is exactly where the Radio Shack capacitors are lacking - they have too high of an ESR and therefore cannot filter out noise and ripple.

As for the Ripple Current rating, this is a rating of how much ripple a capacitor can filter before it begins to overheat.

When buying new capacitors, you first want to look up the brand and series of the original ones in your circuit, then find a datasheet for them and see what their ESR and Ripple Current characteristics are. Then, based on that, you buy new capacitors that have the same or lower ESR and same or higher Ripple Current rating.

With that said, what were the original capacitors on your PSU (brand and model)?
This also raises the doubt - what if your power supply is working fine but you concluded that it's not because you used inadequate Radio Shack capacitors? In this case, you may be just $10 or so away from a perfectly working power supply again without all of those external power supplies.
I would certainly give it a try. Hope you haven't thrown away any of the removed parts yet.

You can order capacitors from here (badcaps.net), digikey.com, or mouser.com. Let me know what the originals are so I can suggest a replacement.

=============

**** EDIT ****

Oh nice, you got it working!
(lol you fixed it faster than I could type my post ).

Well, I would still encourage a complete recap - maybe we can get your PSU running properly with good caps and no external power supplies again.
(and if not, you can always keep it the way it is, now that you know that it works).

As for integrating the PSUs into one - I do have a few ideas, but they may or may not work, and now that you have a working power supply, I'm not willing to suggest them that much, just in case they don't work (but I will if you really really want to).

[Xeniczone]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Lol, seems that you're the man of the hour in my book. I wired in that separate 12v linear PSU and the turned the TV on and it worked perfectly. I played Killzone 2 on it for 40 mins didn't see a problem. My dad doesn't like me playing games on the new 55" Sony because he is worried about Image Persistence, but I don't think new LCDs are affected by this. The Philips had image persistence problems, but I think it is because of the CCFL heating up the LCD panel which causes it.

I would like to turn this TV into a LED TV by replacing the CCFL backlight, but I'm not sure if it would be worth it. It would fix the image persistence if my theory is correct, but The LCD panel is already 4 years old, but then again, the TV wasn't worth fixing the first time. 40" TVs cost about 400-500 dollars. A new PSU is 130-240 dollars. :/

Would it be possible to run all this of one power supply. I would need to test the amperage being pulled by both the 1500mA PSU and the PC PSU, but I see that there are two different grounds so this wouldn't be possible correct?

[Xeniczone]

Re: Philips LCD 42PFL5432D/37 - Bad PSU

Right.
That's because on T904 (the standby transformer), the auxiliary winding gets its power from the main winding.

Ahh, okay may bad. Again, I apologize, I should know more about transformers, but I never learned anything about them in school and never did any research online about them. I need to find me a good book. Is the Aux winding just a 1:1 winding or something like that?

Well, I looked through the TEA1507 (IC904) datasheet again, and it says that the minimum start-up voltage is 10.3v. Therefore, use the 12v, 1500mA linear power supply. I don't think a regulator IC will be needed.

Alright I will give this a try right now.

By the way, those capacitors you used for the replacement are huge! What brand and series are they?

They are ones I bought at radio shack, so I'm not sure of the actual branding or anything because I'm sure radio shack just buys them and places their logo on the them.

The reason for the size difference compared to the original caps is because of the ratings. C955 was original a 2200uF @ 16v. I replaced it with a 2200uF @ 32v, and because it is an axial-lead cap doesn't help with the sizing. C951, C952, and C953 were each 1500uF @ 32v and I replaced all of them with a 4700uF @ 32v. Sure the replacement is 200uF larger than the original ones, but since they had a 20% tolerance, I didn't think it would make much of a difference. I assumed it would be fine based on the wiring diagram. I'm not sure why they used 3 small capacitors when they could have just used one large one.

I will update with results.