Philips 42PFL5432D/37

[Lobo]

Re: Philips 42PFL5432D/37

Yeah, I was thinking of just replacing it because they are relatively cheap. I found one for 20 dollars.

But anyway, I wonder if PoteauPet has taken another look at her T-conn board? Curious to see if she has the same prob.

[budm]

Re: Philips 42PFL5432D/37

15~22uf25v surface mounted or try using low ESR through hole type. But one thing that bother me is that the voltage is that high, I do not expect it to be higher than 12vdc. I would look for replacement T-CON because I think it will go out completely soon.

[Lobo]

Re: Philips 42PFL5432D/37

Yeah, the cap is no longer there. So what do I replace it with? My cheap multimeter was reading about 15-16 V.

[budm]

Re: Philips 42PFL5432D/37

So right now the cap is no longer in place? I had a feeling that the cap has high leakage or shorting out, I will not run the TV without it since the circuits may be exposing AC ripple voltage due to missing filter cap, unless there is another cap with the same value hooked up in parallel with this cap.

[Lobo]

Re: Philips 42PFL5432D/37

Uh, I went to check the voltage with my multimeter and the solder holding the component was so hot that it fell right off the board...

The funny thing is after that fell off, my picture came back. The TV works now. I'm baffled, what do I do now? Just leave it and worry about it being a fire hazard? Or what? haha

[Lobo]

Re: Philips 42PFL5432D/37

That is a cap, C69 , in the picture that looks bad. You should be able to take a voltage reading on the cap, the bar is the Postive side in this case. You can try cool spray on this cap.

So looking at the pic named "top angle" would you say that the left side is positive?

[budm]

Re: Philips 42PFL5432D/37

The one from Costco works just fine. I used to buy the expensive freeze spray made for electronics repair. You can try Radio Shack, they used to sell these freeze spray for electronics troubleshooting. You can verify if the canned air is OK or not by just spraying it on to a glass and see if it leaves any residue.

[bbjunkie]

Re: Philips 42PFL5432D/37

Careful, some canned air contains liquid propellant and when the can is turned upside down, it comes out instead of air (I found out the hard way spraying "air" at my digital camera sensor) I suggest if you are going to try this, use a can of freezer spray instead.

Do you have a can of compressed air duster? They sell them at Costco 3 cans for about $6, just turn the can upside down and blow the cold air on the T-CON to see if it will start working again, then you can try just cool each IC or components on the T-CON board to find out which one is temperatue sensitive.

[budm]

Re: Philips 42PFL5432D/37

By the way, your camera should have MACRO mode for closed up function.

[budm]

Re: Philips 42PFL5432D/37

That is a cap, C69 , in the picture that looks bad. You should be able to take a voltage reading on the cap, the bar is the Postive side in this case. You can try cool spray on this cap.

[budm]

Re: Philips 42PFL5432D/37

What I did on one of the TV I fixed is to leave the T-CON metal cover off, then I use a small CPU cooling fan to blow cool air on to the T-CON board using the switched 12VDC for powering up the fan, another TV I used heatsink to cool the IC.
http://s807.photobucket.com/albums/y...%20LTV-32W3HD/

Do you have a can of compressed air duster? They sell them at Costco 3 cans for about $6, just turn the can upside down and blow the cold air on the T-CON to see if it will start working again, then you can try just cool each IC or components on the T-CON board to find out which one is temperatue sensitive.

[Lobo]

Re: Philips 42PFL5432D/37

Okay, I don't think it's a diode. I'm no expert here. And I hope the pics aren't too big. My camera doesn't really have a macro setting, so I did the best I could...

[Lobo]

Re: Philips 42PFL5432D/37

That's exactly what I was thinking. Like cutting a hole right in the back of the TV and mounting a fan directly over the power supply. Just to try to prevent any further hardware from failing.

I had some time to take a closer look at the T-con board and I see an SMD with what appears to be some slight burning on the PCB beneath it. I can't tell what it is (maybe a diode) there are no identifying marks on it. On the PCB right next to it is "C69".

My camera really sucks, if I can get a decent pic of it I'll post it. Hopefully someone will know what it is.

[Scenic]

Re: Philips 42PFL5432D/37

If we do manage to get these tv's fixed, do you think it would be possible to wire in a fan or two? I've got plenty of old PC fans laying around.

I did something like that on a Samsung 40" LCD. Found a switched 12V (actually 13V) output of the PSU, fed that into an adjustable voltage regulator which runs a 80mm fan on the back of the TV, blowing straight down onto the PSU.
Temps have dropped dramatically (from burnt fingers down to handwarm), even though the fan just runs at about 3.5V (starts up on its own at 2.8V + a bit of headroom)

The back of the TV looks a bit ugly / hackjob-ish but hey.. that's not what you're supposed to look at

[Lobo]

Re: Philips 42PFL5432D/37

This post is real exciting to find out the outcome.

Yes it is!

Who knows, maybe those crappy capxons would have lasted longer if that PSU wasn't kickin' out so much heat. If we do manage to get these tv's fixed, do you think it would be possible to wire in a fan or two? I've got plenty of old PC fans laying around.

Anyway, when I have time this weekend I'm going to have a closer look at all the boards. And since I assumed it was only the Capxons that were bad, I'll probably be looking to replace all of the other caps just to rule those out. Caps are cheap and I could always use the practice with soldering anyway.

[budm]

Re: Philips 42PFL5432D/37

This post is real exciting to find out the outcome.

[budm]

Re: Philips 42PFL5432D/37

The last symptom I see it being mention is that the backlights and sound stay on but not pictures on the screen, so I would suggest to verify if she is loosing the vcc to the T-CON board or not, if the 12v is still there on the T-CON fuse, then I would use cold spray on the T-CON to see if the pictures will come back on.

[retiredcaps]

Re: Philips 42PFL5432D/37

I suspect she is loosing the VCC for the T-CON or the T-CON is dying.

If you are refering to PoteauPets, her TV has had multiple problems.

1) Obviously bad Capxon caps on the main board.
2) The 24V DC disappearing on the inverter boards due to bad Capxon caps (not bloated).
3) Overheating causing the picture to disappear. If a fan is pointed at the back of TV, then it works greats.

Right now, we are left with the two options you mentioned above.

1) There are still some Lelon caps that need replacing on the power board that are part of the 12V rail.
2) I did mention the chimney affect back in post #109 and how that might be causing the t-con to fail.

https://www.badcaps.net/forum/showpo...&postcount=109

I'm sure she (and the regular members here) will welcome any suggestions that you might have.

[budm]

Re: Philips 42PFL5432D/37

The VCC feeding the T-CON board is fed through a switched transistor (this is very common set up used in the TV and monitor t-con power supply section), so when the TV is off, the CPU will send the command to turn off the backlights inveter, T-con board, tuner section, and anything that does not need power to be on to save power.
By the way those three caps on the main board were for the switching power supply and the connector next to it are the connector for the T-CON, large IC is for the Class D audio amp section, you can see the speaker cables (RED and BLACK) on the two connectors close to the IC.
When T-CON has no VCC, you can see the screen glow in the dark if you look in the darkened room because the backlights are still on, some time it is hard to see the glow because some LCD has very high contrast so the screen is very dark when the LCD is off.
I suspect she is loosing the VCC for the T-CON or the T-CON is dying.
http://s807.photobucket.com/albums/y...m/LCD%20panel/

[retiredcaps]

Re: Philips 42PFL5432D/37

This TV runs extremely hot.

I came to that conclusion a while back when caps on the logic board are bloating. Normally the caps on the logic board don't undergo the same stress as those on the power board.

T-con board maybe?

1) Check the fuse on the t-con. A good fuse should measure less than 1.0 ohms.

2) If the fuse is good, see if you get 12V DC voltage.

3) Do you have a source hooked up to the TV? If you have no sound, that could be an indication the problem is on the main board.