LG 55LD630 Stand by, not power On

[8ternity]

Hi,

I had a LG 55LD630 which has a problem. When i plug the TV, the red power light stay lighted and when we open the TV with the remove, the power flash slowly several times.

No screen or clicking is getting happen. I double check for bad caps, fuses, resistors, everything seem to be in perfect shape.

I need help. Im stuck and doesn't know how to resolve this issue. I also not found any Service Manual for this television.

I will add attachements of the power board and video board.

Note: I'Ve not checked the T-Con board, i don't think it may be the t-conn the problem.

Any help is appreciated. Thanks a lot.

[Andrew F. Ali]

Re: LG 55LD630 Stand by, not power On

My interpretation is Main Board problem is the fault here.

[8ternity]

Re: LG 55LD630 Stand by, not power On

My interpretation is Main Board problem is the fault here.

Audio/Video main board?

On this serie, what ca be the issue? Capacitors, fuses, Mosfet? What should i check?

[8ternity]

Re: LG 55LD630 Stand by, not power On

I found a strange parts into the Main Board.

It's look like a SMD fuse. It's transparent and we clearly see with my microscope that it's clear and we seen some elements on it.

I had no conductibility with my tester. Either with ESR, if it's a capacitor.

Does anyone know what is it ?

[8ternity]

Re: LG 55LD630 Stand by, not power On

Does anyone has an idea of this smd parts? Never seen this parts before, the part number written on it give no results nowhere.

Not having the Service Manual too, so i had no clue what this parts is.

[8ternity]

Re: LG 55LD630 Stand by, not power On

PS. I found on the circuit that parts # is X1002 (seems to be a fuse). But can't find nowhere with that number A042N.

Does anyone has the Service Manual for 55LD630 can tell me the part # of the X1002 is?

[retiredcaps]

Re: LG 55LD630 Stand by, not power On

X on the PCB usually denotes a crystal/clock oscillator. F denotes a fuse. See

https://en.wikipedia.org/wiki/Reference_designator

X1002, then is likely some sort of crystal/clock oscillator.

If you look at this datasheet, the Epson crystal looks something like your photo.



If you do a search for your TV as an image, you will stumble across a 55LD650 service manual



While not the same, it might be close enough to give some clues as they might be in the same 55LD6x0 family.

[8ternity]

Re: LG 55LD630 Stand by, not power On

I found the mainboard is used into another model. I follow the Diagnostics procedure, and the cystal clock is 32 khz. I had no oscilloscope to test it. But did you know if we test with conductivity multimeter test mode is suppose to conduct ?

[retiredcaps]

Re: LG 55LD630 Stand by, not power On

I follow the Diagnostics procedure, and the cystal clock is 32 khz. But did you know if we test with conductivity multimeter test mode is suppose to conduct ?

Some multimeters can measure HZ so you should be able see 32khz if your meter has such measurement capabilities. Some of my Fluke meters can read HZ.

[8ternity]

Re: LG 55LD630 Stand by, not power On

Measured to 32.75 khz. My VICKY VC99 has it.

I will continue to measure the rest of the debugging procedure.

Thanks.

[8ternity]

Re: LG 55LD630 Stand by, not power On

Question: I follow the procedure, but i don't read the proper voltage (20 Volt and 12 Volt). If the TV can't turn on, did the reading of 20, 24 and 12 volts are supposed to be readed ?

[budm]

Re: LG 55LD630 Stand by, not power On

The PWR-ON (PS-ON) is generated by the main board, the main board sends out this ON command signal when power switch is activated, this PS-ON is used for turning on the rest of the power supply sections of the power supply board.
So do you have PS-ON signal or not? If you do have the 20VDC and the 12VDC that means the PS-ON is present.
For the TV to function, if the main board is getting the stby Voltage to run, when the power switch is activated, then the main board MUST send the PS-ON, to turn on the main power supply, the BL-ON to turn on the backloghts, the Dim control to control the backlights level, the ON command to turn on the switched MOSFET on the main baord to supply the power to the T-CON board.

[8ternity]

Re: LG 55LD630 Stand by, not power On

I do have the 3.4 volts on 3.5 verry shortly when pressing the power switch. But that's all. I do not have read of 12V, 20V or 24V on pin 2.

I've also try to read the 5.0V on IC chip but i only read some mah value, no voltage higher than 1V.

So the mainboard seem's to be the issue, not the power board right?

[budm]

Re: LG 55LD630 Stand by, not power On

"I do have the 3.4 volts on 3.5 verry shortly when pressing the power switch." Are you saying that you do have 3.4VDC on the PWR-ON PIN for seconds and then it goes down to 0VDC?
Or you are talking about 3.5VDC STANDBY Voltage?
We are trying to find out if you do have PWR-ON Control signal or not.
The STANDBY 3.5VDC power supply should be steady within +/-0.1 V or so.
It sounds like you are checking the STBY 3.5V pin instead of the PWR-0N PIN.

[fzabkar]

Re: LG 55LD630 Stand by, not power On

These three models apparently use the same chassis (LA01B):

42LD630 47LD630 55LD630

Here is a service manual for the 37LD450 which also uses the LA01B chassis:



I don't know if it is any better than the 55LD650 manual.

[8ternity]

Re: LG 55LD630 Stand by, not power On

"I do have the 3.4 volts on 3.5 verry shortly when pressing the power switch." Are you saying that you do have 3.4VDC on the PWR-ON PIN for seconds and then it goes down to 0VDC?
Or you are talking about 3.5VDC STANDBY Voltage?
We are trying to find out if you do have PWR-ON Control signal or not.
The STANDBY 3.5VDC power supply should be steady within +/-0.1 V or so.
It sounds like you are checking the STBY 3.5V pin instead of the PWR-0N PIN.

Im having 3.4 volts about on 3.3 (see picture of boot check) half or quart of a second after that it's drop close to zero when pressing power button.

I had 3.4 volt on P404 PWR_ON pin 1 (really fast). I don't know if the results must stay at 3.4 volt, or when only pressing PWN button.

On the next step, it's said "Check Multi Voltage";
P404 pin #2, i had reading of some mh/a (less than .25 volts); same for Pin #17.
But that step, i don't know if the TV need to be started to get thèses reading. If the TV can't start, did i need to get another reading ?

[8ternity]

Re: LG 55LD630 Stand by, not power On

These three models apparently use the same chassis (LA01B):

42LD630 47LD630 55LD630

Here is a service manual for the 37LD450 which also uses the LA01B chassis:



I don't know if it is any better than the 55LD650 manual.

Yeah i've found 55DL520 which is based too on the same chassis. The 55LD650 is not the same, i've double checked. Thanks a lot for the infos.