Samsung PN50A510P3FXZA Plasma No Picture

[R_J]

Re: Samsung PN50A510P3FXZA Plasma No Picture

That does'nt suprise me as everything seemed to check ok on the power supply
It could be control board or possibly ysus, I'm not sure if the ysus talks back to the control board if there is a problem. but the control board does output a Vs_ON signal
I do believe VS_ON needs to be high, in post #38 I gave a way to try it

[kevinm34232]

Re: Samsung PN50A510P3FXZA Plasma No Picture

I will try this..

From some other information I found on the alarm board is (I believe) a steady green led means standby voltage is there and ok. if that led was blinking, it would blink the error.

Another thing to try would be unplug cn802 and using a 1k resistor jump 5 volt standby (I believe it is JP131, check it to be sure) to Vs_on and see if that turns on the Vs.

[Andrew F. Ali]

Re: Samsung PN50A510P3FXZA Plasma No Picture

Some PSUs do not turn on the VS if there is a no-load condition. If you are self-testing the PSU outside of the TV you should put a load on the VS pin and GND This load is a test load and is 2 100W 120Vac light bulbs in series. BTW are there any fuses on the Y-Main Bd that may be open and so even in circuit the PSU sees no-load and does not switch on?

[kevinm34232]

Re: Samsung PN50A510P3FXZA Plasma No Picture

All the fuses look to be fine, I am testing with everything in the TV using the forced logi c board operation, with the main board disconnected.

[R_J]

Re: Samsung PN50A510P3FXZA Plasma No Picture

It is likely better to connect the lamps to do the test (like I mentioned before). Better than risking damage to the Y-sus

[kevinm34232]

Re: Samsung PN50A510P3FXZA Plasma No Picture

Can you show where I'd connect the lamps I've never done that, besides using one in the main power supply fuse.

[Andrew F. Ali]

Re: Samsung PN50A510P3FXZA Plasma No Picture

Reconnect everything to their normal positions. Concentrate on getting VS and VA going before trying to do anything else because without them nothing will work not even the Logic Bd. test since you would need VS and VA for the Logic Bd. test to work and see the various screen patterns.

[R_J]

Re: Samsung PN50A510P3FXZA Plasma No Picture

I believe Va is working for him it is only Vs that is not.
To connect the lamps Just unplug CN803 from the power supply and connect the lamps across Vs and Ground
You need two lamps because the voltage will be around 200vdc

[Andrew F. Ali]

Re: Samsung PN50A510P3FXZA Plasma No Picture

1. Disconnect the PSU from the Main Bd and Y-Main Bd. so that the only connector left on the PSU is the ac connector.
2. Connect the two (2) 100W 120Vac light bulbs in series across the VS pin and GND on the connector that was going to the Y-Main Bd.
3. On the connector that was connected to the main Bd. connect the PS-ON to GND
4. On the same connector, connect the VS-ON to StdBy 5V using a 100 Ohm resistor
5. Plug in the ac
If the PSU is working:
a. The Test lights should come on bright and remain ON
b. The VA voltage should come up
c. other voltages on the connector should come up eg: 17V !3V. %V etc

I am not too sure of the pin nos. but look carefully at the connector.
Let me know what you have and if you can name the pins on that connector just in case I missed something.

[Andrew F. Ali]

Re: Samsung PN50A510P3FXZA Plasma No Picture

I believe Va is working for him it is only Vs that is not.
To connect the lamps Just unplug CN803 from the power supply and connect the lamps across Vs and Ground
You need two lamps because the voltage will be around 200vdc

Even with the 'new' board??

[R_J]

Re: Samsung PN50A510P3FXZA Plasma No Picture

Even with the 'new' board??

I'm just going by post #39
It would take 5 minutes to check the power supply board on the bench with 2 resistors and 2 lamps

[Andrew F. Ali]

Re: Samsung PN50A510P3FXZA Plasma No Picture

I'm just going by post #39
It would take 5 minutes to check the power supply board on the bench with 2 resistors and 2 lamps

To do Post #39 the connector to the Main Bd MUST be removed (to prevent damaging the Main Bd.) and the connector to the Y-Main MUST be removed, and the two test-lamps connected across VS pin and GND and the resistor placed across the VS-ON pin and StdBy 5V pin then the PS-ON pin could go straight to Chassis GND and yes that will turn on the PSU.

[kevinm34232]

Re: Samsung PN50A510P3FXZA Plasma No Picture

This may be a stupid question but I remember last time I looked for a 100W incandescent light bulb I had a hard time finding one. Does it matter if it's a fluorescent or LED?

[R_J]

Re: Samsung PN50A510P3FXZA Plasma No Picture

It can be 2 60 watt incandesent lamps in series, It is just used to put enough load to have the circuit operate and confirm the voltage comes up. thats it. and no led's ccfls etc will not work. go steal them from the bathroom

[R_J]

Re: Samsung PN50A510P3FXZA Plasma No Picture

To do Post #39 the connector to the Main Bd MUST be removed (to prevent damaging the Main Bd.) and the connector to the Y-Main MUST be removed, and the two test-lamps connected across VS pin and GND and the resistor placed across the VS-ON pin and StdBy 5V pin then the PS-ON pin could go straight to Chassis GND and yes that will turn on the PSU.

Post #39 said that he installed the replacement board and it operated the same as the other power supply board.

Thats all so I figure it operated the same VA = ok Vs = 8 volts. so the fault is elsewere

Is there a full moon today

[kevinm34232]

Re: Samsung PN50A510P3FXZA Plasma No Picture

I picked up the supplies I will do this test shortly, thanks. (60W bulbs only available)

I got these 2 bulb sockets, this is how I'd wire it correct?

[R_J]

Re: Samsung PN50A510P3FXZA Plasma No Picture

Yes

[kevinm34232]

Re: Samsung PN50A510P3FXZA Plasma No Picture

Just noticed that there is a PS_ON on both CN801 and CN802 > (where VS_ON is), yet the two PS_ON don't ohm out to each other. I have been using CN801 PS_ON to turn on PS. Any thoughts?

[R_J]

Re: Samsung PN50A510P3FXZA Plasma No Picture

Yes I saw that, I would use the PS_ON on CN801 because we know it works, I would then check if you have Va, (like you had before) I would then connect the +5stby via another 1K to the Vs_no on cn802. and see if you have Vs and lights
I traced both PS_ON lines and they both go to the error board.

[kevinm34232]

Re: Samsung PN50A510P3FXZA Plasma No Picture

Welp did the test and I feel bad I didn't do this earlier, but it worked lamps light up and VS comes up to about 205-210V.

I've never had a model where the load was necessary so sorry about this, and I didn't have the materials to do the test until today..

I did try to leave the harness connected to either X or Y main individually, but it didn't work that way either..

(Both PS's are working..)