TCL Model 55S405 - No Pic, No Backlight, No Sound - HELP!!!

[koolx]

Hi guys.. I got a tcl tv model 55S425 with no picture, no backlight and no sound. Do you think its an led or main board issue? What do you suggest I buy to fix it?

[nomoresonys]

So no indicator light on the front of the tv at all?

[koolx]

Originally Posted by nomoresonys

So no indicator light on the front of the tv at all?

The screen is dark but you can still make out the menu if you look hard enough. It's a backlight issue to my knowledge.

[budm]

Please attach good clear pictures of the whole backside of the TV using 'Go Advanced' so we can see all the boards.
What Voltage testing have you done so far?

[koolx]

Originally Posted by budm

Please attach good clear pictures of the whole backside of the TV using 'Go Advanced' so we can see all the boards.
What Voltage testing have you done so far?

Hi budman. I havent done any voltage testing since I'm not versed in that field of electronics. What do you suggest?

[budm]

1) Well, right now we have no idea what we are dealing with since we do not have the TV in front of us to look at.
2) You need to have digital mutli meter and know how to use it to perform some Voltage testing, if you do not have any tools then all you can do is visual inspection or just start buying boards to see if it will fix the problem or not but if you have bad backlights problem then buying boards will be useless, that is why Voltage testing is needed to help narrowing down the problems.

[koolx]

Originally Posted by budm

1) Well, right now we have no idea what we are dealing with since we do not have the TV in front of us to look at.
2) You need to have digital mutli meter and know how to use it to perform some Voltage testing, if you do not have any tools then all you can do is visual inspection or just start buying boards to see if it will fix the problem or not but if you have bad backlights problem then buying boards will be useless, that is why Voltage testing is needed to help narrowing down the problems.

Hi budm. I have a friend who might have a multimeter. If I do get it, will you help me test which components to zero in on on my tv?

[budm]

Make sure to read the meter manual first, and the TV needs to be plugged into GFCI outlet for safety then we can go from there.

[koolx]

Originally Posted by budm

Make sure to read the meter manual first, and the TV needs to be plugged into GFCI outlet for safety then we can go from there.

Hi bud.. I did reset the tv through my roku remote while the it was dark. After that I'm able to see "TCL Roku TV" flash once for a split sec but thats it. I can repeat this many times but the tv still wont turn on. Given this do you still think its an led strip issue or something else?

Btw I'm trying to get that multimeter.

Also if its an led strip issue and I buy led strips, do I have to solder them onto the tv?

[nomoresonys]

Can pick up a basic multimeter for about 10 bucks at the big box stores.

[budm]

Originally Posted by koolx

Hi bud.. I did reset the tv through my roku remote while the it was dark. After that I'm able to see "TCL Roku TV" flash once for a split sec but thats it. I can repeat this many times but the tv still wont turn on. Given this do you still think its an led strip issue or something else?

Btw I'm trying to get that multimeter.

Also if its an led strip issue and I buy led strips, do I have to solder them onto the tv?

1) We cannot tell anything until we do some measurement first.
2) If it is bad LED strips, then you will need to dissemble the LCD panel to get to the LED strips. Are good at mechanical assembly/disassembly? This is large panel so a very good chance of breaking it if you have no experience.

[koolx]

Originally Posted by budm

Make sure to read the meter manual first, and the TV needs to be plugged into GFCI outlet for safety then we can go from there.

Hy bud.. ok so my super gave me his sperry mulitmeter. He also gave me a "pen" to check for other measurements. I assume the pen will be used to check the led strips. Let me know if both these devices will suffice and how to start fixing my tv.. thanks bud.

[budm]

That pen is for probing for active AC for electrician, not going to be use for trouble shooting the TV.
I hope you get the user manual for that meter, it looks like it is made for Electrician.
Please read the manual.
https://www.sperryinstruments.com/en...s-DM2A-Digital

[budm]

Originally Posted by budm

Please attach good clear pictures of the whole backside of the TV using 'Go Advanced' so we can see all the boards.
What Voltage testing have you done so far?

So where are the pictures?
You do have GFCI outlet to plug the TV into, correct?

[koolx]

Originally Posted by budm

Make sure to read the meter manual first, and the TV needs to be plugged into GFCI outlet for safety then we can go from there.

Originally Posted by budm

So where are the pictures?
You do have GFCI outlet to plug the TV into, correct?

Hey bud.. I read the manual that youve attached. Although I'm no techie I get the gist of it.

As for a GFCI outlet, I can possibly get one from my super. I'll ask though I doubt he has one.

Below are the pics as you've requested...

***CORRECTION*** My tv is TCL model 55S405. Sorry for the typo in my original post.. I'll change it!

.

[budm]

1) You should try setting meter to read DC V and measuring some battery Voltage such as AA, car battery to see what it shows on the meter just to get to know your meter because correct DATA of your measurement is very important for us.
2) Your bath room outlet should be protected by the GFCI so you can use the outlet with extension cord. https://www.dfliq.net/blog/what-is-gfci-outlet/

[koolx]

Originally Posted by budm

1) You should try setting meter to read DC V and measuring some battery Voltage such as AA, car battery to see what it shows on the meter just to get to know your meter because correct DATA of your measurement is very important for us.
2) Your bath room outlet should be protected by the GFCI so you can use the outlet with extension cord. https://www.dfliq.net/blog/what-is-gfci-outlet/

Sure I'll have the super help me with that. But fyi I'm not sure you read the last part of my last reply. I edited it after posting it. Just wanted you to know that I made a typo in the title of my thread. The correct model of my unit is 55S405, NOT 55S425. I sent a note of this to the mod and hopefully he should correct it.

I'll let you know when I'm ready for your instruction. Thanks bud!

.

[budm]

Please verify the TV full model number.
According to shopjimmy, the boards for the 55S425 do not show the power supply used in your TV, your power supply board is P/N 08-L14TWA2-PW220AL
There are many versions of the same TV model.
https://www.shopjimmy.com/tcl-08-l14...wer-supply.htm
According to SJ, your power supply board is used in 49S405TDAA and 55S405LGAA.

[budm]

Originally Posted by koolx

Sure I'll have the super help me with that. But fyi I'm not sure you read the last part of my last reply. I edited it after posting it. Just wanted you to know that I made a typo in the title of my thread. The correct model of my unit is 55S405, NOT 55S425. I sent a note of this to the mod and hopefully he should correct it.

I'll let you know when I'm ready for your instruction. Thanks bud!

.

OK, these are the boards used in your TV model 55S405.
https://www.shopjimmy.com/catalogsea.../?q=55S405LGAA

[budm]

OK, as you can see, Red connector P2 of the power supply board has pin names located on the bottom side of the board. The exposed pin on the top side of the board are ODD number pins that you can carefully check the Voltage of each pin easily, the EVEN number pins, you will need to use skinny probe to probe the pins from the wire entrance side side of the connect, all the Voltage testing has to be done with all connectors in place.

Turn the TV on and then check the Voltage on each pin, Black probe of the meter connected to the metal chassis of the TV for meter ground reference:
Report the reading as shown in the format below. Make sure to count the pin correctly.
PIN 1: PDIM (PWM Dimming control) = xxx V
PIN 2: BL-ON = xxx V
PIN 3: GND = xxx V
PIN 4: P-ON (PS-ON:mpower supply turn on control signal) = xxx V
PIN 5: N.C. (NO CONNECTION)
PIN 6: A_DIM (Analog Diming control) = xxx V
PIN 7: GND = xxx V
PIN 8: GND = xxx V
PIN 9: 12VDC = xxx V
PIN 10: 12VDC = xxx V
PIN 11: 12VDC = xxx V
PIN 12: 12VDC = xxx V
PIN 13: 12VDC = xxx V
PIN 14: 3D_EN (3D MODE Enable) = xxx V

Pictures provided by shopjimmy.