Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

[Louis82]

Hello there,

Can someone help to troubleshoot this power board KB109WJQZ for Sharp TV LC-60C6500.

No STB voltage, DC filter caps shows 165V. I found a defective diode location D7950 part number SB2100. I replaced it with another Diode STPS2150 from another Sharp board and I still not getting any STB voltage. Suggestions on what to check next ?

Thanks in advance

[dick_barton]

Re: Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

Check capacitors C7950A and C7950B

What is the part number for Q7120

[R_J]

Re: Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

Check R7900 to see if it is open, it should be 2.2 ohms, if it is open ic7903 is bad

[Louis82]

Re: Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

Thanks guys. I did notice R7900. I been looking for IC7903. I will report back soon if I have it.

[Louis82]

Re: Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

Ok. There is definitely an improvement. 5V present on Pin 15 which is BU5V but still nothing on Pin 24 STB. Any thoughts?

[budm]

Re: Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

Pin 24 'STB. is the BL-ON pin which it receives the BL-ON signal from the main board.
You need to report DCV (when TV is OFF and when power switch is activated) for all the pins of the PD connector so we can see what are missing.
You must put down pin number and follow by pin names so we do not have to guess what they are.

[Louis82]

Re: Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

Thanks guys. Installed circuit board on Tv and is working properly. Thank you for your time.

[budm]

Re: Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

Can you please post the DCV reading on PD pins so we will have the reference to as what they should be for working board (board connected to the main board)? It will help lots of people in the future.

[seosan]

Re: Repair Power Board KB109WJQZ for Sharp TV LC-60C6500

Thanks guys. Installed circuit board on Tv and is working properly. Thank you for your time.

Hello Louis. Did you get any voltage on pin 24 (STB) ?

[seosan]

I'm back to tell you how I solved my problem with a Sharp LC-50U45 (Japan).

First, I identified the damaged LED bar and removed the respective wire from the connector, leaving all the others connected.

Then I interrupted the [ERROR] signal from the connector between the power supply and the main board. I connected this wire to the device's body (GND).

And finally, I entered service mode with the [input] and [- volume] buttons, turning on the power... and voilá.