Samsung PN50C450B1DXZA

[ses4you]

I have a steady red light on the front of TV. Pressing the power key yields no response - no clicks from relay, no sounds of any kind. The following was measured on CN801 of the power supply.

1. 3.34v (PS-ON)
2. 5.16v (Styby)
3. 0
4. 15.27v
5. GND
6. GND
7. .454V
8. .454V
9. GND
10. 15.27V
11. 15.27
12. .454V

I performed the Samsung's Fast Track Troubleshooting

[SM].pdf&mfg=Samsung


Power On Sequence

STBY 5V (Pin 2 CN801) - Reads (5V)

PS_ON (approx 3.3V - 0V) (Pin 1 CN80) - T reads (3.3V)

VS_ ON (approx 0V – 3.3V) (Pin 6 CN80) reads (0v)


VS - 213V
VE - 76.3V (AJUSTED TO 86V)
VS - 213V
VSC – 187.7V

[ses4you]

Re: Samsung PN50C450B1DXZA

Is it my Logic Board or the Main Board that is cause the problem of not powering up.
Thank you for the help

[rccrasher65]

Re: Samsung PN50C450B1DXZA

I have both of these boards for this tv set.

[mmartell]

Re: Samsung PN50C450B1DXZA

Your results are confusing the way they're written. If you're saying PSON reads 3.3v before and after pressing the Power button then it's not changing state and your main board is at fault.

If it's supposed to go low then you can remove pin one from the connector (main board side) and attach it to ground then plug the tv back in and see what happens.

[ses4you]

Re: Samsung PN50C450B1DXZA

Sorry about the confusion on the reading. When i plug the TV up to the power source and measure the voltage at the power supply board connector CN801, PSON reads 3.3v before and after pressing the Power button.

Should the PSON after pressing the Power button read something less then 3.3v?

[dick_barton]

Re: Samsung PN50C450B1DXZA

PS_ON normally changes state so that when, for example it may be 3V or more in standby when you press the remote to come out of standby it goes to 0V.

On some sets this may be the other way around but it is a definite change.

[ses4you]

Re: Samsung PN50C450B1DXZA

understand, no change on the PS_ON. I ordered the main board, will let all know the out come. Thanks again

[ses4you]

Re: Samsung PN50C450B1DXZA

It's a No Go on the main board swap.

I tried the logic board test. I disconnected the main board and jump pin 3 and 4 of that 4-pin square test connector. I then jump the PS-ON pin to ground. The TV came on with a white bright screen. So I am thinking the main board is good.

[dskall]

Re: Samsung PN50C450B1DXZA

Seems you have a power button problem. Does it work with remote?

[maxvalutech]

Re: Samsung PN50C450B1DXZA

Yes when you jumper ps-on to ground you are of course taking 3.3v down to 0. Trace and check all from power button to and including connector cable wires and connector soldering main board . Power board seems ok.

[ses4you]

Re: Samsung PN50C450B1DXZA

I trace and checked the wires from power button to the main board connector. I wiggled and push the wires into their connectors. The TV comes on now with the remote and TV' s power button.

Will look for bad soldering and let all know. Thanks