RCA 46LA45RQ no standby light or turning on

[marlboroa]

Hello, I have a rca 46LA45RQ that seems to not have power but it does have some on the power supply. Theres no standby light or backlight flash. I have tested the voltages on the power supply and they all test good. The 24 volt on the motherboard is at 12 volt not 24. other then that it all looks fine.

[ammarben]

Re: RCA 46LA45RQ no standby light or turning on

have you 5v stb?

[ammarben]

Re: RCA 46LA45RQ no standby light or turning on

check U8 voltage regulator on main bord if its output is 5v

[marlboroa]

Re: RCA 46LA45RQ no standby light or turning on

This tv is wierd. it has voltages even when off.
Anyway U8 is 12.87 on one leg and 5.03 on the other.

[budm]

Re: RCA 46LA45RQ no standby light or turning on

It needs standby Voltage to keep the main board alive.

[marlboroa]

Re: RCA 46LA45RQ no standby light or turning on

it has standby voltage.

[marlboroa]

Re: RCA 46LA45RQ no standby light or turning on

Heres some readings
Power supply
GND
5.22 ADJ
.06 BK_ON


4.78 PS ON
5.23 +5VSB
GND
GND
5.23 +5
5.23 +5
GND
GND
12.84 +12
12.84 +12


Then on the Main Board its 12.53 where it should be +24v

[budm]

Re: RCA 46LA45RQ no standby light or turning on

"4.78 PS ON" You have power supply on signal.
".06 BK_ON" You do not have backlights on signal.

[marlboroa]

Re: RCA 46LA45RQ no standby light or turning on

I know but i Cant figure out want needs to be checked on the back lights. From some video i watched it looks like this set has all the voltages on regardless if the set is on or off. Just not sure about the BK_ON. I also dont have any kind of standby led or power on led. The button does work though as i can measure voltage spikes when its pushed.

[budm]

Re: RCA 46LA45RQ no standby light or turning on

The command is generated by the main board, you have PS-ON signal from the main board so it is partially working. You have main board problem.

[marlboroa]

Re: RCA 46LA45RQ no standby light or turning on

Yep, anyone happen to have a schematic or where to start looking on the main board?

[marlboroa]

Re: RCA 46LA45RQ no standby light or turning on

Anyone??