Problem x-board on Samsung PS51E550OD1P

[Bibu]

Hi, i have a problem with a Samsung plasma PS51E550OD1P
The problem is that the X- buffer low board (lj41-10171a) doesn't work correctly, when this board is plugged are present only 5 and 15v, there aren't VA anD VS voltage.

I just try to test the power board without the x-board ( i make a bridge between vs-on and 5v) and the vs and the va are correct.

On the xboard i don't see any faulty, all the capacitors and the SMD resistors are good... Where is the problem?

Sorry for my english please

[ReeceyBurger123]

Re: Problem x-board on Samsung PS51E550OD1P

The Ymain gets it power from Xmain on these common issue is Ymain failing but makes the Xmain appear to be at fault as they share the energy recovery circuit.. Unhook the Ymain plug and try to boot also check for S/C between Vs and ground.

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

Thanks for reply, but if i connect the xmain, the vs voltage must be present? Because i just try with only x-board connect, and i can see only 5 and 15v

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

Anyone that can help me please?

[ReeceyBurger123]

Re: Problem x-board on Samsung PS51E550OD1P

Right does your DMM have a diode mode ? Also do you know how to check for S/C ?

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

Yes i can do it... But i must do it in x-main board?

[ReeceyBurger123]

Re: Problem x-board on Samsung PS51E550OD1P

Right unplug the Ymain from Xmain and unplug Xmain from Psu. Then if you look at the connector you can see something like "Vs" put your meter in diode mode then black probe to chassis ground then red probe to "Vs" on the Xmain what do you get ?

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

Ok, with all unplugged, in the vs ( there are 2 vs pin in the same connector), i have 0 and beep

[ReeceyBurger123]

Re: Problem x-board on Samsung PS51E550OD1P

Vs on the Xmain or Ymain either way thats a dead short to ground on the Vs input which is not good ?

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

probably...but this could be caused by what ? the board of the tracks are in good condition ... it could be a mofset or resistance ?

[ReeceyBurger123]

Re: Problem x-board on Samsung PS51E550OD1P

Shorted transistor, they are mounted under the pcb. Remove it and test them for S/C.

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

Where i can see the chassis number of this tv? I don't find any service manual with product number

[Alastair E]

Re: Problem x-board on Samsung PS51E550OD1P

Service-manual will be utterly useless anyway--No schematics are ever included for Samsung sets--like most of em these days. Firelighter fodder only.

--If Y is bad, all the service-manual will say is replace it!

--Pointless rubbish--not a service-manual, its a joke!

[tech2014]

Re: Problem x-board on Samsung PS51E550OD1P

Service-manual will be utterly useless anyway--No schematics are ever included for Samsung sets--like most of em these days. Firelighter fodder only.

--If Y is bad, all the service-manual will say is replace it!

--Pointless rubbish--not a service-manual, its a joke!

I agree 100%, I don't even bother wasting my time downloading SM anymore.

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

and without datasheet as you do ? You will make tests at random ?

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

There is anyone that can help me to test this transistor FGD4536TM with a dmm?

[Nick's Tvs]

Re: Problem x-board on Samsung PS51E550OD1P

Take it out of circuit, go to ohms and test every leg in every direction. You should always read O.L on your meter in every direction except for 1 where you will read anywhere between 5 mega ohms to 15 mega ohms. When I say test every leg in every direction, I mean red on drain black on source, and then black on drain, red on source. Then red on drain black on gate, and same thing black on drain, red on gate. Finally red on gate, black on source and then black on gate red on source. Doesn't matter if you know which leg is which, as long as you don't get readings in the K ohms.

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

Take it out of circuit, go to ohms and test every leg in every direction. You should always read O.L on your meter in every direction except for 1 where you will read anywhere between 5 mega ohms to 15 mega ohms. When I say test every leg in every direction, I mean red on drain black on source, and then black on drain, red on source. Then red on drain black on gate, and same thing black on drain, red on gate. Finally red on gate, black on source and then black on gate red on source. Doesn't matter if you know which leg is which, as long as you don't get readings in the K ohms.

Hi nick thanks for help.

My problem is that there isn't drain gate anD source, but there are gate emitter and collector... Are the same with differen't names?

[ReeceyBurger123]

Re: Problem x-board on Samsung PS51E550OD1P

Its the same way to test them though.

[Bibu]

Re: Problem x-board on Samsung PS51E550OD1P

Its the same way to test them though.

Thanks i found the transistor shorted