Samsung PN42A450P1D Plasma screen doesn't prime

[Fwrothy]

Another scrapyard TV ...
Got power, chimes on and off, displays 5 red blinks ??
X & y boards hum and led flashing green on control.
Checked voltages at all test points-good
Checked all fuses incl. e-f buffer-good.

Not sure what to do next-do I try to trick it on via main?

[Alastair E]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Check the Diode, D5015 near top edge of Y-SUS for S/C. Its a UF4007

[MagicSmoke]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

You can disconnect LVDS cable from mainboard to logic, look at logic board and find 4 holes 1,2,3,4 jumper 3,4 with alligator clip or the like, then disconnect power cable from main and use a resistor to jumper 5v Stby to PS-on. There might also be a VS-on pin, if so then that will need a jumper also.

If it's working properly there should be test patterns displayed, If not then better pics of all boards are needed.

When logic LED flashes, is it once every second or once every 5 or so seconds?

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Thanks Alastair E, do you mean 5014?
If so it checks out at .485 ( fluke83), good no?

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Thanks MagicSmoke, steady once a second, ok I'll replace the ef heat sink and try to power it up, just wasn't sure about try to force it on if it doesn't even prime( been reading plasma threads trying to figure out TS procedures)

[Alastair E]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Aye--My mistake Thats the diode--sounds like yours is OK.

Whats the Voltage on that rivet marked Vscan? Should be about -190

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Aye--My mistake Thats the diode--sounds like yours is OK.

Whats the Voltage on that rivet marked Vscan? Should be about -190

Yup Vscan(Vsc on panel sticker),Ve, Va and Vs are all spot on.

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Tried the self test-nada

[tom66]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Is control board light blinking steadily? (About once a second)

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Yup as per# 3&5

[tom66]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Weird... do you have access to an o'scope? Are all fuses, including small 15V or 5V ones ok on the Y-main?

[MagicSmoke]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Check all of the LVDS cables to and from logic board and reseat them.

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

I only found the one fuse on the ymain...

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

boards:

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Weird... do you have access to an o'scope? Are all fuses, including small 15V or 5V ones ok on the Y-main?

I do! Picked up a tek2465 last spring but have not used it yet, been looking for an isolation trans...

Fl1&2 on Y-main, are those fuses?

[MagicSmoke]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Yes the green ones are a fusible resistor.

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Yes the green ones are a fusible resistor.

So I should have 5 & 15vdc at the exposed legs?

[tom66]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Yes, sometimes there is also one for Va (~60V)

Do you have a 10X probe for your scope and are you familiar with using one?

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime

Rl1 is ~26vdc
Rl2 is ~35vdc

10x probe is my only probe at this point and I don't have much practical experience.

[Fwrothy]

Re: Samsung PN42A450P1D Plasma screen doesn't prime


Ok I found the GREEN FUSES F5002 top right quadrant of Y-main, 15vdc.
F5007 is in the bottom right quadrant under the heat sink, 92vdc.
Both measurement use chassis ground.