philips 42pfl8694h (8404h) startup problem

[Term1903]

hello friends,

tv has problem at startup procedure, when main power is on, tv tries to wakeup , after three times trial it turns into error(protection) mode and gives red led flashing twice.

what I have checked;
3.3v standby voltage is OK,
mainboard pulls the ps_ON pin to low(this happening three times) at this period, psu 12V becomes active, and I can see 1.2v 3.3v 5v on the mainboad at measuring points.

attached you will find the service manual and some photos

thank in advance for any suggestion,.

[Maalobs]

Re: philips 42pfl8694h (8404h) startup problem

Layer-1 error code 2 on a PFL model.
It's high probability that you will need to reflow the BGA-chip beneath that undersized heatsink.

This model has hardware SDM, so you can check the layer-2 error code.
Go to section 5.2.1 in the service manual and find this bullet point:

Analog SDM can also be activated by, on the SSB,
shorting for a moment the solder pads SDM [1] (see Figure 5-1).

It's right above the Figure 5-1 image:


The SDM overrides the protection mode which allows you to measure voltages on all power rails, and it enables the layer-2 error code which can narrow down the problem area for you.
Go to section 5.5.4 to find table 5-3 where all the error codes are listed:


Let us know what your layer-2 error code is.
It will blink two digits, each at a different speed, pause, and then repeat.
Two blinks at the first speed followed by three blinks at the second speed for example, means error code 23.

[Term1903]

Re: philips 42pfl8694h (8404h) startup problem

hi
thanks for the reply

unfortunately SDM pin doesn't activate anything, still same action in standby led ,blinking red led twice.

I give up searching for the fault, and unfortunately I didn't find any replacement card.

power board is working(when I jumpered 3.3vsb and ps-on pin, I can get 12v and 24v, 0v on BCKlight_ON , 5v on BCKlight_dim)

I will try to adapt a universal LCD board(lcd conversion board and a NT68676 controller board), but one thing I am not sure is the backlight_ON and backlight_DIM, do you know how these two pin works?


thanks in advance for all replies...

[nomoresonys]

Re: philips 42pfl8694h (8404h) startup problem

sure, I test it with cable unhooked at mainboard, I use about 1k resistors for jumping in case I make an error in connection, I jump thru end of connector, just seems easier, then jump from bcklight-on to 3.3vsb along with your other jumper ps-on to 3.3vsb and see if all your voltages are as expected and your backlights come on and stay on. May also need a jumper on backlight-dim to 3.3vsb, maybe try it without backlight-dim jumper if backlights don't come on try adding the backlight-dim jumper.