Sharp lc32d42u seems dead

[metropical]

plugged in after being off for quite some time. No OPC lights. Tried flashlight test for backlight check, nada.
Pulled the PS and checked all diodes including the 5w(?) D7908 that was the issue last time. All diodes check OK in circuit with DVM diode test.
No caps look unhappy. It is 17 years old. Was gonna fix and give to my brother.
But is there anything else to try or is it likely met its match.?

[EazyBone]

Does the fuse have continuity? Are you getting voltages at the legend clip to main board?

[R_J]

Do you have standby BU5V?

[metropical]

fuse has continuity.
Found the attached pin outs for the 3 PS board connectors.
I'll check the BU5V but what is the legend clip at the Main board?

[R_J]

Here is a thread with a schematic TV Sharp LC 37D42U (DPS 178AP) - Badcaps If you do not have the standby 5v check if R7002 and R7933 are ok, if R7002 is open, ic7905 will likely be bad, I would always replace C7912 as well.

[metropical]

standby 5V is good. I have the schematic.
In that thread, you refer to Q7902/Vc 23v, which appears to be in a cage.
Is there a test point I can check with the PS still in and powered?
Are VCC & VCC_ON 5v?

[R_J]

If you have 5v standby, the next voltage to check would be the PS_ON, this is the control voltage for the rest of the power supply and is supplied from the main board, it tells the Power Supply to turn ON.
If you wish to check the power supply voltages by itself, disconnect the cable between the main board and the power supply (PD connector) and connect about 1 1K resistor between standby 5v and the PS_ON pins on the power supply, this will turn on the power supply and you should have UR6v, UR10v, UR13v, if you do then the fault is likely on the main board.

[metropical]

is there no way to check those voltages without the resistor? My days of having parts around are long gone.
If it is likely a main board problem, at the price of new TVs now, I'll probably bring it to ecycle.
It is so old that shopjimmy wasn't interested in my shipping the pcb's.

[R_J]

You can just connect the PSc_ON to the 5v directly as there already is a resistor (R7301) in Q7301 base circuit, just make sure you don't connect the 5v to ground.

[metropical]

Can this all be done without the Main 1 & 2 (PD) plugs connected?
Could J7914 be used for 5v and J7918 be used for PS_ON?
Don't have the dinkiest gator clips.

[R_J]

NO, J7914 is BU5V, BUT J7918 is GROUND. You need to connect BU5V to PD pin1

[metropical]

finally got to it.
Had 5.76v at p1 of Main 1.
p3&4, nothing.
p7&8, 10v
p11&12, 12.76v
there is a red LED on inside the cage on the left as you face the back of the TV.

[metropical]

Hi RJ. If you have a minute to advise. Thanks, Fritz

[metropical]

little bump