samsung le37c630k1w standby lights but no power on

[Xristakis795]

hi to all
at first the problem of tv is has light on standby but if i press or fron the remote control or fron the power button to be on it retains on standby
on the above tv i have download the service manual of power supply bn44-00339b from electrotanya
when i remove the plug cn802 from mainboard i measure in pin 1,3,5,17 12.5 volt
on pin 16 5.2 volt and on the pins
11, 13, 14 4 volt maby i have problem here i think must be 5 volt right ?
and on the plug cni801 i can measure on the pins 10 ...14 24 volt and the backlight is on normal
but if i connect the mainboard with the plug cn802 the voltages on the pins 1,3,5,17 are not steady variable from 0 -12 volt the same happens and on the pins 11,13,14 variable from 0-4 volt
can anybody tell me if the problem is on power supplu or mainboard ?
thanks in advance

[dskall]

Looks like you may have a mainboard problem.

[Xristakis795]

from your exprerience something is short on the minboard and causes this problem or the better is to find used mainboard from ebay ?
and on the pins which must have 5 volt and measure 4 volt you thinks i havent problem ?

[nomoresonys]

check the voltage regulators on mainboard.

[nomoresonys]

did you try unhook the cable from mainboard to tcon, then see if those voltages are still unstable?

[Xristakis795]

yes sir i did this the same result
you mean the regulators of the mainboard right ?
i will measure and i will write about
as about as the voltage of power supply instead 5 volt i have only 4 volt on the particular pins wich tell you above do you think is this the reason to cause the problem ?

[CapLeaker]

Missing PSon is most of the time a problem with the mainboard’s main IC. Nothing much you can do about it besides replacing either the board or the IC.

[Xristakis795]

for what particular ic do you mean sir ?
and the voltages when the plug of power supply connected to the mainboard
which variable from 0 - 12volt its not mean something like short on the main ?

[nomoresonys]

voltage testing: https://www.youtube.com/watch?v=ocqnqmBxiqY

[Xristakis795]

thanks
i have seen this video
its very good