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Jack, Technician
Category: TV
Satisfied Customers: 8072
Experience:  40 years experience as audio,video repair and installation tech
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philips 42pfl5432d/37 turns on and stays on as long as nothing

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philips 42pfl5432d/37 turns on and stays on as long as nothing is on that input. as soon as you change to a active input i.e xbox on and running tv powers off. if you remove (xbox from input tv stays on fine. same with coax and hdmi inputs. power or main board issue?
Hello , my name is Jack
Perhaps I can help you with this problem but first i would have a few questions;

When it turns off with a unit connected and turned on , can you turn the tv back on ?
If so , does it stay on for a while or just shut down right away ?
Did this problem appear all of sudden or slowly got worse ?
Customer: replied 3 years ago.

it appeared all of a sudden. with a unit connected I can power it back on for about 1 sec then it shuts down again

O.k and another question;
When it shuts down , does the power light flash at the front ?
Customer: replied 3 years ago.

no when it shuts off no noises no blinking light. if you didnt know any better you would think someone hit the power button on the remote. then you can turn it back on and count to 8 then it shuts off and just goes back to solid red light on front of tv


O.k , one thing to try if you haven`t done it yet , disconnect everything or set the tv to an input where nothing is connected and open the menu then go through the different items in the menu to see if it will turn off then.
Customer: replied 3 years ago.

already done that. if nothing is connected to a input the tv stays on. can navigate menus and change aspect ratio. I have the back of the tv off. no bad caps on the power board.

O.k then , at first I was tempted to say the power board as pretty much all the problems I`ve seen with this model came from the power board , namely bad caps.

Still could be the power board that fails when it is asked to deliver more current i.e when the tv is processing signal.

Can you see the plugs that go to the backlight inverters ?
There should be two connectors side by side labeled CN905 and CN 903 , set the tv on a live input and disconnect those plugs to see if you will get the sound and if the tv will stay on ?
Note that you won`t get the picture

Customer: replied 3 years ago.

ok removed the back light plugs. powered on tv. turned on xbox heard sound. it stayed on for 15 seconds. then i heard a quick popping sound from the speakers as the tv shut off. light went red. didnt blink

o.k , can you give me a couple of minutes?
Customer: replied 3 years ago.



On the main board there is the LVDS connector CN850 , it is a 40 pins connector .
Replug the backlights on the power board and unplug that CN850 on the main then try the tv again with a signal.

Customer: replied 3 years ago.

Hi Jack. So with removing the cn850 the unit is staying on but not displaying any picture at all i reconnected the backlights as instructed. i can hear sound from the unit


O.k but the tv will stay on without shutting down ?

Reconnect that lvds plug without turning off the tv or unplugging the power cord ?
Customer: replied 3 years ago.

as soon as i plugged in the cn850 unit shut off instantly

O.k then this looks like a main board problem , namely the sub-power that feeds the t-con board connected at the other end of that lvds cable.

There is a 14 volts coming from the power board that goes into the main board where it is sud-divided into 12 ,5 and 3.3 volts , by connecting the t-con (with a signal) it pushed it over what it can supply and it just shuts down those voltages.

In a repair shop there would be other test that could be tried to confirm that but it requires some specialized equipment.

So to resume, from what you tried and without being there with tools and meters , I would put my money on the main board.

Right now there is something confusing here , the service manual gives me one part number for the main and the aprt list I have gives me 2 versions.
Can you give me the numbers on the bar coded sticker of the main board ?
Customer: replied 3 years ago.

cbpf72mkpi and lower half of barcode p4m574370217


engraved in top corner of board is dlh 715t2303-3

Sorry it took a while but that board part number CBPF72MKPI A.K.A 996510008583 was difficult to find as all the regular suppliers seem to be out of stock, I found one that seems to have it at the link below;


You can also use the part numbers I gave you if you`d like to do your own shopping.

Give it a try and you can reach me here at any time after this chat is closed if you have questions about this.
Thanks and please take the time to rate my answer

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