philips 42pfl5432d got sound no backlight

[allsmith]

Re: philips 42pfl5432d got sound no backlight

It looks like they are for Dimming control signals for the backlights. That is the T-CON it is connected to.

There is also a wire from main board that goes to master inverter thats called bright adjust.
Would either bright adjust or dimming controls keep back lights from turning on?

Could i have got a bad pair of inverters, or do you have any other ideas?

Thanks

[allsmith]

Re: philips 42pfl5432d got sound no backlight

You all got any other ideas on any other tests i could do to see why i have no backlights?

Or should i just write this one off?,not a big deal i dont have much in the tv and i can return the inverters i bought within the next 30 days or so.

Think i should go ahead and put my original inverter boards back on and have you all walk me through in testing those IC's on the master?

The only things i can think of(not that i know anything about this stuff) is that i have bad lamps?

Although my PSU is working and have 24v on the inverters,I keep worrying about those illinois capacitors that the other guy put on the PSU,That they are putting out dirty or weak power?(again i have no experiance with this stuff)

Any last help on this one would be appreciated,and i know you all are busy helping others with there tv's so no big hurry here.
In the mean time im gonna pop in some Rush and Pink Floyd in my 30 yr old (unrestored) stereo equiptment and enjoy how good and reliable vintage electronics sound!Heck with watching tv! lol

Thanks all!

[tom66]

Re: philips 42pfl5432d got sound no backlight

I had a TV with a defective t-con fuse, which also caused the inverter to not come on due to the missing signals from the T-con to synchronise the backlight.

[Mr Bill]

Re: philips 42pfl5432d got sound no backlight

The small chirp you hear on the main inverter side, did you hear that with your original inverter board? The only thing i can think to try that doesn't cost anything would be to start unplugging each bulb one at a time and turning the tv on and see if the noise goes away. If the noise goes away then that would indicate a likely bad bulb. If you do want to write this project off send me a PM. I live about 90 miles away from you.

[allsmith]

Re: philips 42pfl5432d got sound no backlight

The small chirp you hear on the main inverter side, did you hear that with your original inverter board? The only thing i can think to try that doesn't cost anything would be to start unplugging each bulb one at a time and turning the tv on and see if the noise goes away. If the noise goes away then that would indicate a likely bad bulb. If you do want to write this project off send me a PM. I live about 90 miles away from you.

Yes the original inverter board chirped also.
It will chirp once every time the power button is pushed, but only if you give it a few minutes in the off position.
I also hear one chirp on the main board when pushing power.
Now keep in mind the single chirp is very quiet and would probably not be heard if the back cover was on

[allsmith]

Re: philips 42pfl5432d got sound no backlight

I had a TV with a defective t-con fuse, which also caused the inverter to not come on due to the missing signals from the T-con to synchronise the backlight.

Would FP1 on my T-CON board be a fuse Tom?
Its the only F designator i can find.
It does test open.
Have not tested to see if there is voltage on it yet.
Thanks!

[Mr Bill]

Re: philips 42pfl5432d got sound no backlight

FP1 is a fuse. If it reads open and you check voltage and it has it one side and not the other than it's bad. You might be on to something if the tcon sends a signal to the inverter to turn the ccfl bulbs on.

[allsmith]

Re: philips 42pfl5432d got sound no backlight

FP1 fuse is fine,
got 12v on both sides
It tests 0.00 ohms now,i must not have been getting a good connection on my first ohm test.
Need to put some deoxit on my test probes!

[Mr Bill]

Re: philips 42pfl5432d got sound no backlight

What is the part number of your main board? Will you post a picture of the backside of it? Thanks

[allsmith]

Re: philips 42pfl5432d got sound no backlight

What is the part number of your main board? Will you post a picture of the backside of it? Thanks

Well im glad you had me pull the main board! As i have not pulled it before.

The other guy has (tried) to replace 4 capacitors on the main board and his signature soldering skills are present!!(his solder job on the PSU looked the same!)

The pads on the board of the caps that he changed are all messed up,just like on the PSU!

The 4 blue Lelon caps are the ones he changed,can't believe he used Lelon!
Can you even buy Lelon caps,or maybe he took them out of something else?

I can try and save the solder pads like i did on the PSU,but i dont know if i can save this main board or not!

It looks like at least one of the caps he soldered in is not even making connection,and the pads are pulled!

Do you think these messed up caps could keep the backlights from coming on or is this just another problem?

Ive tried atleast 4 or 5 times to see if i can see an image on the screen with a flashlight when playing a source and have never been able to see any image.But i have sound(but that could just mean the amplifier is working)

I'll try and resolder his work and see what happens,Shopjimmy prolly has main boards but looked a little pricey,but if i can return them with just a small restock fee,It might be worth trying another board?

What do you think of this mess?
Thanks!

[Mr Bill]

Re: philips 42pfl5432d got sound no backlight

Shop Jimmy is showing your main board in stock for $54.12
https://www.shopjimmy.com/index.php/...83-main-board/

Those blue caps look like radio shack lelons. The green ones are probably lelon caps too. I can't comment on whether the soldering is causing your issue but it looks like there could be a cold joint in there. Alot of main boards, particulaly in monitors use lelon caps. I think the shop jimmy picture has a radio shack lelon in the picture.

The reason i asked to see the main board was i wanted to see if your board had an ic labled 7003 (L5973). I had a 32MF321D that was rescued from the trash. I recapped the power supply and it was good as new. It sat in my basement for over a month until another member was having an issue with the same tv. Being a nice guy and all i went to check the voltages on that chip and i shorted one of the pins. As soon as it went ZAP the picture went away backlights and all. So i'm wondering if your main board has the same chip on it. But you can always try shop jimmy as a plan 'B"

[allsmith]

Re: philips 42pfl5432d got sound no backlight

Shop Jimmy is showing your main board in stock for $54.12

Looks like this is what I'll be doing ,As the other guy ruined the pads on all the caps he changed! I dont see no way to fix the traces as its a multi layer board.I cant see how any of the caps he put were even getting a connection as he must have pulled the pads when he desoldered the old caps out!

Those blue caps look like radio shack lelons.

Thanks i didnt know radio shack sells Lelon.

The reason i asked to see the main board was i wanted to see if your board had an ic labled 7003 (L5973).

I looked on both sides of board and dont see any designation that high,my numbers are all 3 digit,and i looked for that part # on all IC's and dont see it.

This mess on the main board might explain why i cant see an image on the screen with a flashlight?

Do you or anybody else know what the 4 blue caps he changed out do on this board?

Even though i have sound,and the main board is sending 3.3v to BL_ON,Its turning on the 24v and 12v section of the PSU,And sending 12v to T-CON board could those 4 messed up caps he put still keep my backlights from coming on?

Thanks for your help

[Mr Bill]

Re: philips 42pfl5432d got sound no backlight

I don't know what the caps do on the board. The original guy could have tried to change them thinking they would maybe fix the tv. OR they could have been bloated. I'm hoping the main board sends a signal to the tcon and the tcon tells the backlights to turn on. I believe your tcon has a ribbon cable going to the inverter. Since you hear some noise from the main board when you first turn the tv on this might be it. The only other thing it could be is tcon or bulbs.

BTW,
what is your panel on this tv? I might have a tcon laying around you could try if the main board doesn't work.

[allsmith]

Re: philips 42pfl5432d got sound no backlight

I don't know what the caps do on the board.

Well we do now! I got her working by repairing the traces for the caps that guy installed! Watched it for about 30 min,Its seems to be working good.My repair is not pretty,but effective,had to solder all the positive pins on the top of the board and the negative's on the bottom.

I'm hoping the main board sends a signal to the tcon and the tcon tells the backlights to turn on.

You where right!

I might have a tcon laying around you could try if the main board doesn't work.

Thank you for the kind offer and all your help!



I think i will still buy a new board from jimmy,but if i do i should replace all the caps on it.
Or i might just say heck with it as this one is working now ,but i still should replace all the caps on it too.
Do you think the way i mounted the caps will cause any problems like being to close to each other,or other components?

I want to thank you and everbody else that helped me with this project!
I greatly appreciate it!
Thanks ,Lonny

[sam_sam_sam]

Re: Philips 42pfl5432d got sound no back-light

I think you will alright as long as you can put it back together and the cap leads are not touching any thing they should not be touching

I once fix a LCD TV that I did not have the right value cap so I use two of the same value to have the right uf value put one on one side of the board and the other one on the other side of the board I did NOT want spend any money on it if was not going to work very long It cost me about $45.00 to recap it

It had a lot of caps


It worked for a hole year like that until I had to recap the hole board because it start being a problem child again

I will make it work ..........>>>>>>>......>>>>> this TV came from the side of the road in a trash pile .....>>>>.....>>>>..... I had nothing to lose so I try it and it worked .....>>>>>> IT LOOK LIKE CRAP the one on the back of the board was just hang there with two wires to the cap it was the only way to make it fit .....>>>>>> I am still using this TV today