Samsung Plasma hpr4272

[Tekno]

Hello guys I am pretty new to repair TV..i have background in computer repair well i got This samsung plasma turns on blank screen...it makes the startup sound but no display...I have checked power supply board seems to be outputting all voltages to all boards and no visible blown caps...how can i confirm Y or Z board is issue...i dont hear any sound but the start up tv sound

[Alastair E]

Re: Samsung Plasma hpr4272

The contol-board has some jumpers on. You cab bridge three and four as I recall, which will give a variety of test-patterns cycling at 10 second intervals....

A pic of the individual boards and the rear complete of the set would be a good start....

[Tekno]

Re: Samsung Plasma hpr4272

will post the pics up tomorrow. thanks for the reply

[Tekno]

Re: Samsung Plasma hpr4272

ok so here are some pictures...

[Tekno]

Re: Samsung Plasma hpr4272

there seems to be a crystal on logic board that has a dent in it…in laptops a faulty crystal causes no display..not sure if this the case with PLASMA tv….i read somewhere to check Y OR Z BOARD for no display issues after powerboard has been cleared..powerboard seems to check out…dont know how to go about troubleshooting the rest of the boards..any help would be greatly appreciated.

[Tekno]

Re: Samsung Plasma hpr4272

only board i forgot to take a pic of is the control board which is under the logic board…would faulty control board cause no display? …tv powers on makes powering on chime..but displays no picture screen stays blank

[Tekno]

Re: Samsung Plasma hpr4272

Common components to check on y sustain ? I suspect it the y sustain board but dont know how to verify

[Glitcher]

Re: Samsung Plasma hpr4272

Have you checked the white ceramic fuse to the right of the larger heatsink? If its good than the main IPM circuit under it should still be working. If so move on to the next step.

Check the MOSFETs under the circled heatsinks, you may find than one or more of them has gone bad. You will have to desolder the heatsinks to get to them. They are in parallel so you will have to lift the legs of each one to test if they are shorted.

(Not as common) But there may also be some shorted diodes, you can test them in circuit if they are shorted or not.