ps-42q97hd no picture but have sound

[comptek]

i have a PS-42Q97HD on first inspection i found a few bulged caps on the right hand side of the power supply, since i replaced them all seems well but still not getting a picture...
I have checked all voltages and they all seem correct inc vs and va as per panel sticker, i checked y and x for and failed fets etc and all seem fine,
the panel on switch is lighting up even the quick flicker when normally no signal etc would be shown but there is nothing at all, on the small logic board behind main logic the led to the right i believe its marked (2000) lights up and goes off and the led on the left near the y sustain ribbon flashes at 1 sec intervals
Power supply is the BN44-00194A, all fets and transistors look and test fine been over all boards looking for dry joints as standard.
No menu shows up or volume etc and i plugged another main board in from a PS-42Q96HD and made no differance i have all other boards from the 96HD but they are different parts even thoughthe screen is the same all but the screen im working has 42HD(W2+) on the barcode and the donor doesnt :/
many thanks
Gary

[sordids999]

Re: ps-42q97hd no picture but have sound

Posting pictures of the back of your tv showing the boards with clear pictures may help you more with fixing your problem

[sordids999]

Re: ps-42q97hd no picture but have sound

How to test your buffer boards
https://www.youtube.com/watch?v=51SZsfH60EY

i think this is the Q97 pictures
on the panel you will see a sticker this needs to see if all voltages are matching up VS/VA/VE/VSC
etc etc

[ReeceyBurger123]

Re: ps-42q97hd no picture but have sound

Does the panel glow in a dark room ? Also common issue on these is the Ybuffer failing.

[comptek]

Re: ps-42q97hd no picture but have sound

Does the panel glow in a dark room ? Also common issue on these is the Ybuffer failing.

yes Reece like i said the screen lights up and you get the flicker as it would show no signal etc comes on like a lit black screen

[ReeceyBurger123]

Re: ps-42q97hd no picture but have sound

So either the control or Mainboard isnt running. Do you know how to do test patterns on these ?
Also you could try entering the service mode do you know how to do that ?

[comptek]

Re: ps-42q97hd no picture but have sound

How to test your buffer boards
https://www.youtube.com/watch?v=51SZsfH60EY

i think this is the Q97 pictures
on the panel you will see a sticker this needs to see if all voltages are matching up VS/VA/VE/VSC
etc etc

thanks Sordids 999 here is the info pics required
On boards the voltages are as follows
VS=206.7
VA=63.8
VSC=191.1
VE=99.6

[comptek]

Re: ps-42q97hd no picture but have sound

So either the control or Mainboard isnt running. Do you know how to do test patterns on these ?
Also you could try entering the service mode do you know how to do that ?

yes tried the test pattern setting main board unplugged linked ps/on to ground and joined top to pins on the 4 way pin block at the top of the logic board pins 3+4
no image

[ReeceyBurger123]

Re: ps-42q97hd no picture but have sound

Hmm sounds like the control board then buddy as the sustain drivers are working and you are getting panel glow however they arnt being told what to do. You did unhook the Lvds as well lol ?

[sordids999]

Re: ps-42q97hd no picture but have sound



just unplug top connector then using a wire connect across pin 3/4

Did you test your buffers ?

[comptek]

Re: ps-42q97hd no picture but have sound

sorry couldnt load photos the proper way

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[comptek]

Re: ps-42q97hd no picture but have sound

just unplug top connector then using a wire connect across pin 3/4

Did you test your buffers ?

that what i did with the logic board gonna check buffers now for shorts

[comptek]

Re: ps-42q97hd no picture but have sound

Hmm sounds like the control board then buddy as the sustain drivers are working and you are getting panel glow however they arnt being told what to do. You did unhook the Lvds as well lol ?

yes all that was attched to logic was he small cable going to psu and the ribbon cables going to boards

[sordids999]

Re: ps-42q97hd no picture but have sound

yes tried the test pattern setting main board unplugged linked ps/on to ground and joined top to pins on the 4 way pin block at the top of the logic board pins 3+4
no image

linked ps/on to ground ??

[comptek]

Re: ps-42q97hd no picture but have sound

linked ps/on to ground ??

yes well return as it shows on samsung site to take ps on low it power on the psu ok

[sordids999]

Re: ps-42q97hd no picture but have sound



Just try disconnecting the cable going to the main board in the picture and connect wire to 3/4 on the control board for test patterns

[comptek]

Re: ps-42q97hd no picture but have sound

Just try disconnecting the cable going to the main board in the picture and connect wire to 3/4 on the control board for test patterns[/QUOTE]

thats what i did the only things connected was the small grey plug to psu and the ribbon cables
lvds and mainboard unpluged mainboard end that is

[sordids999]

Re: ps-42q97hd no picture but have sound

And you have tested your buffer board ? and that voltage readings you took is that with YSUS/ZSUS etc connected ?

[comptek]

Re: ps-42q97hd no picture but have sound

And you have tested your buffer board ? and that voltage readings you took is that with YSUS/ZSUS etc connected ?

yes i used pin 1 of the top buffer connector and on diode mode tehy were all around 0.620
VS=206.7
VA=63.8
VSC=191.1
VE=99.6

[sordids999]

Re: ps-42q97hd no picture but have sound

And the led on the control board is blinking ?