LG 60LB5200 will not turn on

[vinceroger69]

Originally Posted by CMS

Did you ever resolve this? I have the same model and get the same readings. I swapped out the main board with no luck. No one has a power supply board in stock, so I can’t try that.
I know how to use a multimeter and solder electronics but no diagnostic ability. The tv is only a few years old and I don’t want to have to buy another.
This was our everyday tv that sat in our dining room for a month while we remodeled. Plugged it in and all I get is the flickering green light.
I appreciate any and all help.

On the power supply can you take the voltage readings from the connectors if there is any writing by the connectors can you tell us that too, like 12 then the voltage readings, The connector has 12V, 24V, EN, and GND what reading do get across the primary capacitor measure across the two legs be careful as testing on the hot side of the psu so dont let probes slip etc or risk any shocks .

[budm]

Originally Posted by CMS

Did you ever resolve this? I have the same model and get the same readings. I swapped out the main board with no luck. No one has a power supply board in stock, so I can’t try that.
I know how to use a multimeter and solder electronics but no diagnostic ability. The tv is only a few years old and I don’t want to have to buy another.
This was our everyday tv that sat in our dining room for a month while we remodeled. Plugged it in and all I get is the flickering green light.
I appreciate any and all help.

Op never give an answer as to what OP has at the 'EN' pin.

[WTRWLKR]

I don't think Kyle provided that information; however, I did post that in post #3.

12V = 6.95V
24V = 15.64V
EN = 2.54V

[budm]

Sorry, I mean Kyle.
CMS needs to report the reading.

[CMS]

My readings were nearly identical to Kyle.
12V = 6.9V
24V = 15.6V
EN = 2.54V
Caps = 167.6

[dick_barton]

When the power supply is disconnected from the mainboard, what is the voltage at the EN pin, power supply end.?

[CMS]

When it is disconnected it goes to 0.

[dick_barton]

Very carefully what DC voltage do you have between pins 1 & 2 of the U1 (TEA1755)

[dick_barton]

.

[CMS]

Dumb question, but this is on the back side of the power board?

[nomoresonys]

Yes back side.

[dinko87]

Hi guys, I am a brand new member. I have the exact same tv with the exact same problem, exact same readings. I just measured Voltage between 1&2 on U1 and I get 14.4V (with nothing plugged into the board except the 120VAC).

[dick_barton]

According to the datasheet given post #8 the startup voltage needs to be approximately 22V with an undervoltage lockout (switch IC off) at approximately 13.4V



Edit
Are there resistors all connected in series on the HV (pin 16) and also is there a capacitor connected to the VCC (pin1) and if so what is the working voltage given on it?

[dick_barton]

There is reference to the power supply diagram (FA 168P-P5L031-W1.pdf) at this site but I'm hesitant to join up.

[dinko87]

Originally Posted by dick_barton

According to the datasheet given post #8 the startup voltage needs to be approximately 22V with an undervoltage lockout (switch IC off) at approximately 13.4V



Edit
Are there resistors all connected in series on the HV (pin 16) and also is there a capacitor connected to the VCC (pin1) and if so what is the working voltage given on it?

On Pin 1 there are 2 capacitors and then it goes through some diodes and a transistor. On those caps the voltage is also 14.4V

On Pin 16 there is one 10K resistor and the other lead of that resistor ties into pin 2 of that big yellow components (not sure what that even is).

[CMS]

Thank you dinko87 (and DickBarton) for picking up where I left off. I got the same reading between pins 1 and 2.

[budm]

Can I get the pictures of the whole back side of the TV showing all the boards so I can see how they are connected together?
I also need good clear straight shot of the whole top and bottom side of YOUR board.
1) Right now the power supply is running otherwise you will not have any DC at the outputs at all.
2) I look at the bottom side of the power supply board from shopjimmy, the EN pin is not connected to anything at all due to jumper J26 and J27 are missing in shopjimmy's pictures, so I need to see you boards and how they are connected together.
Pictures provided by shopjimmy.
http://www.shopjimmy.com/lg-cov32809...er-supply.htm#
LG COV32809701 Power Supply

[CMS]

Originally Posted by budm

Can I get the pictures of the whole back side of the TV showing all the boards so I can see how they are connected together?
I also need good clear straight shot of the whole top and bottom side of YOUR board.
1) Right now the power supply is running otherwise you will not have any DC at the outputs at all.
2) I look at the bottom side of the power supply board from shopjimmy, the EN pin is not connected to anything at all due to jumper J26 and J27 are missing in shopjimmy's pictures, so I need to see you boards and how they are connected together.
Pictures provided by shopjimmy.
http://www.shopjimmy.com/lg-cov32809...er-supply.htm#
LG COV32809701 Power Supply

I attached the photos you requested.

[CMS]

Sorry. The pics are upside down.

[WTRWLKR]

The picture in post #5 is the back of my board. I can take a picture of the front, if you would like. However, I'm thinking CMS has covered both sides and the back of the TV.

It is odd that it looks as if the EN pin is not actually connected to anything.