LG 50PB560B Plasma wont turn on

[Bloopeta]

Re: LG 50PB560B Plasma wont turn on

Just been testing voltages on PCB, when board is standalone on bench, readings are

VS 202v
VS 202v
N/C
GND
GND
VA 55.4v
M5V 5.2v

But if connect to mainboard (with nothing else connected to mainboard) the voltages drop to 0, but slowly.

I have tried this with the matching replacement main board with same result.

I even tried another spare LG plasma mainboard I had lying round, that wasnt a match but with the same connector just out of interest and got the same result.

Does this mean anything?? Or give any insight into what the problem may be??

[Bloopeta]

Re: LG 50PB560B Plasma wont turn on

I have now unplugged mainboard , and plugged in cable to ZSUS board, without cable to YSUS plugged inx readings at P134 are

+VS 202v
+VS 202v
NC
GND
GND
+VA 55.4v
+5v 5.2v

At P132 readings are

+VS 201v
+VS 201v
NC
GND
+5V 5.2v
+18V 3.8v

Is the reading for +18 supposed to be that low??

[Bloopeta]

Re: LG 50PB560B Plasma wont turn on

Now with P132 plug back in readings are

P134
+VS 201v
+VS 201v
NC
GND
GND
+VA 55.4v
+5V 5.1v


P132
+VS 201v
+VS 201v
NC
GND
+5V 5.16v
+18V 17.92v


Also dont know if its worth mentioning, but when main board isnt connected, you can hear the hum/buzz of the Power board like its working, but when you connect mainboard to it, it goes completely silent.

[dick_barton]

Re: LG 50PB560B Plasma wont turn on

In another post in this forum about this set they mention the following test points. What voltages do you have.
M_On =
AC_On =
RL_On =
Auto_GND =
17V_Det =
VS_On =
VS_Det =

Service manual https://www.electronica-pt.com/esque...s-pu41a-33547/

[Bloopeta]

Re: LG 50PB560B Plasma wont turn on

In another post in this forum about this set they mention the following test points. What voltages do you have.
M_On =
AC_On =
RL_On =
Auto_GND =
17V_Det =
VS_On =
VS_Det =

Service manual https://www.electronica-pt.com/esque...s-pu41a-33547/

Hi, I gave up with this one, I didnt know what else to try with it, so passed it on to someone else.