RCA LED65G55R120Q TV Set Power issue?

[mwbrown1979]

Hi all. I read through a previous thread regarding this same set, I'm hoping to get some confirmation that I'm on the right track. The set will flash once every 3-5 seconds when powered on. No indicator light, neither standby nor power on. During this 3-5 second cycle the screen only displays 2-3 colored horizontal lines. Will not power on. I've confirmed 120v at the power board, only reading 3-3.5v going out of it. No indications of blown capacitors from what I can see, but I am far from an expert. I read in Mr. Martin's troubleshooting guide I should have 5v standby, etc. With a reading of 3-3.5 do you blame a faulty power board? I really want this set going but I can't throw parts at it blindly Any guidance would be greatly appreciated!

[dskall]

Re: RCA LED65G55R120Q TV Set Power issue?

Need good clear straight on pictures of back of tv with cover off and each board.

[mwbrown1979]

Re: RCA LED65G55R120Q TV Set Power issue?

Need good clear straight on pictures of back of tv with cover off and each board.

here goes..thank you!!

[dskall]

Re: RCA LED65G55R120Q TV Set Power issue?

Need voltages from connector that goes from power supply board to main board. Will need pin#- PIN DESCRIPTION -Pin voltage in standby-Pin voltage when pushing power button and picture of connector on power supply board.
Format:
Pin# - Pin Description - Pin Voltage standby - Pin voltage power on
1 - XXXXXXX - XXv - XXXv
2 - XXXXXXX - XXXv - XXXv
3 - XXXXXXX - XXXv - XXXv
4 - etc.

[bkdadto3]

Re: RCA LED65G55R120Q TV Set Power issue?

I am going to jump in here and say, that I have this exact setup and I am not able to get power to come on but my voltage readings confuse me. Here is what I get at the power board capacitor: 166.9 vdc

At con2 I get
Pin
1 EMPTY
2 EMPTY
3 GND
4 GND
5 13.23 V THIS IS LABELED AS 12V
6 13.23 V THIS IS LABELED AS 12V
7 GND
8 13.23 V THIS IS LABELED AS 12V
9 GND
10 GND
11 GND
12 5.1 V THIS IS LABELED AS 5V
13 5.1 V THIS IS LABELED AS 5V
14 5.1 V THIS IS LABELED AS 5V
15 4.46 V THIS IS LABELED AS PS ON
16 5.09 V THIS IS LABELED AS 5 VSB
17 4.70 V THIS IS LABELED AS ADJ
18 0.4 mv THIS IS LABELED AS BK ON


Trying to figure out if this is a main board issue or a power board issue.

[dskall]

Re: RCA LED65G55R120Q TV Set Power issue?

Do you see an image if you put a flashlight up to the screen?

[bkdadto3]

Re: RCA LED65G55R120Q TV Set Power issue?

No, no video, no led nothing at all.

[bkdadto3]

Re: RCA LED65G55R120Q TV Set Power issue?

This is the state all of the time, all of these voltages are present but no leds are lit anywhere and there is no ability to turn on the tv.

[dskall]

Re: RCA LED65G55R120Q TV Set Power issue?

What is voltage on ps_on when you push power button and when in standby? 18 0.4 mv THIS IS LABELED AS BK ON maybe backlight. Other voltages seem OK

[bkdadto3]

Re: RCA LED65G55R120Q TV Set Power issue?

The voltage is 4.46 v with the switch depressed and when it is not. The power on button makes no difference at all, there are no power leds even lit up on the tv to indicate standby power.

[dskall]

Re: RCA LED65G55R120Q TV Set Power issue?

What is voltage on ps_on when unplugged from main board?

[bkdadto3]

Re: RCA LED65G55R120Q TV Set Power issue?

zero volts

0.0 v

[bkdadto3]

Re: RCA LED65G55R120Q TV Set Power issue?

Still my main cap is only seeing 167.9 vdc

[CapLeaker]

Re: RCA LED65G55R120Q TV Set Power issue?

When the tv goes into test pattern, check the main filter cap voltage and the 24V rail. It sounds like a bad main board to me, but first verify voltages on the PSU. If push comes to shove, disconnect everything from the PSU and force it on. If that PSU checks out all right, then it is a main board problem.

[bkdadto3]

Re: RCA LED65G55R120Q TV Set Power issue?

Well, the person decided to take it to their brother to be worked on. I may never know the root cause. Thanks for the help.

[budm]

Re: RCA LED65G55R120Q TV Set Power issue?

PS-ON is present but you still have only 160Vdc on the filter cap, it shoould be 380~400VDC because the board has PFC Voltage booster circuit, you need to get the PFC circuit working first.
How much experience do you have troubleshooting down to component level and SMD reworks?