PSU TEST ON TV7001-ZC02-01 BOARD

[nomoresonys]

What can I fix here, if 5vsb is not supplied to the motherboard, it is rather powered from 12v.

Ah I see now, they didn't use that pin, connector was unhooked in original picture so couldn't easily tell.

[nomoresonys]

Glad to hear it's fixed, thanks for the followup, appreciate it.

[zafirabdo]

I have same issue. are these readings with the mainboard and LED connected or without. can you show location of R355,R002,C338 on the board and why did you change them?

[nomoresonys]

C338 is the little blue capacitor right next to EC203.

[nomoresonys]

having a hard time spotting those resistors, wonder if they are tucked under one of the heatsinks, you see any?

[nomoresonys]

Check out EC201 and EC210.

[nomoresonys]

Read thread carefully, maybe try suggested in post # 9. After heating caps don't wait til it cools down try tv while it's still hot, youtube is your friend for how to videos, plenty there.

[zafirabdo]

I have already changed EC210, old one was a bit bulged. I have the board out on a bench not connected to the main board. How do I test to see if issue is fixed or not?. When connected to power I am still not getting any voltage reading on LED connectors, not sure if I should. Thank you I found C338. BTW R355 in on the back of the board near the IC. I am not able to find R002.

[nomoresonys]

Dirty test for electrolytic caps if no capacitor tester at hand, can use a multimeter set at about 20k ohms, tv UNPLUGGED, reading should gradually rise or fall, switch leads and should go the other way. You will know if you do the test correctly by the readings, can try it on a good cap that isn't installed also. As always be careful you don't want one of those caps zapping you, if you hold the power button down on tv for 30 seconds with it unplugged, it will help discharge the caps. Can test them with multimeter to be sure they are discharged. Good practice is just never touch anything on the HOT/DEADLY side with your hands.

[nomoresonys]

I have already changed EC210, old one was a bit bulged. I have the board out on a bench not connected to the main board. How do I test to see if issue is fixed or not?. When connected to power I am still not getting any voltage reading on LED connectors, not sure if I should. Thank you I found C338. BTW R355 in on the back of the board near the IC. I am not able to find R002.

You can build a dim bulb tester for a few bucks, youtube is full of how to videos, if there is a short on the board the dbt will light up bright and stay bright. It saves from blowing up components, also if it don't glow bright it should be safe to try the board.

[nomoresonys]

So did you test that resistor? Don't forget to try the hairdryer test in post # 9.

[zafirabdo]

I can not do test post 9. I have already replaced the capacitor but would like to know how to test the board to ensure the capacitor was the only issue. I dont have the TV right now, just the power board on a bench and the power cord.

What do I test & how to check if the board is working or not?

[nomoresonys]

I am not positive how to test this board as stand alone, I'll have to defer to the other members.

[zafirabdo]

I see an R348 near the LED connector but the rating on the board schematic says NC-0R. what does this mean? I dont see the resistor (probably tucked under the transformer) but I am getting an open circut when I measure it. any ideas

[lotas]

I see an R348 near the LED connector but the rating on the board schematic says NC-0R. what does this mean? I dont see the resistor (probably tucked under the transformer) but I am getting an open circut when I measure it. any ideas

NC - "No Connection" - not installed in the specifically specified option (Not Connected)
It is installed when the CON302 connector is missing.

[nomoresonys]

NC on a datasheet means No Connect, open, floating.

[zafirabdo]

Thanks.... however how do pin 3 in con301 and pin 1 in con302 function in the circuit to get the voltage needed by the LED lights?

[lotas]

Thanks.... however how do pin 3 in con301 and pin 1 in con302 function in the circuit to get the voltage needed by the LED lights?

V led.

[zafirabdo]

Thanks again....But pin 3 in con301 and pin 1 in con302 are just connected to each other...they dont seemed to be connected ato any thing on the circuit board. I am getting 240-290 on the other pins when ready to PCB grounds. Again the pCB is not on the TV, it is stand alone when i do these readings.

[lotas]

That's right, that's how it should be, the LED strips are connected in series (like a garland, one LED burns out and all the others stop lighting...), the voltage is high because there is no load (the LEDs are not connected.