LG 42PQ3000 No longer powering on?!

[Jellzy]

Hi all,

Decided too be adventurous today and see if I could source the problem with my plasma.

A quick Google today brought me here and after having a look around and doing a little reading I though what better than to start my own thread.

First of all I'd like to say that this place is great and there's a really delightful community vibe created by what appears to be really helpful members... Never have I seen this on a forum but then that's probably due to the fact I sit on footy and gaming boards.

So with that my problem.

As the thread title suggests my plasma is no longer powering on. It is 4 years old but it doesn't seem to be the screen itself that's gone as it died abruptly last night whilst the missus was watching some reality tv show.

Tried turning it back on only to be greeted with no output of anykind, both picture and sound.

Upon turning it on there's an audible click (relay?) and the led flashes blue 6 times before going solid and eventually turning red.I had a look in the manuals troubleshooting section and nada. Investigation me thinks. So a few googles and a service manual and mulimeter at hand I thought I was ready to do some checking.

That's where you come in as I'm not quite sure where to begin.

Note I had a read through of 'RetiredCaps' Voltage Regulation testing thread https://www.badcaps.net/forum/showthread.php?p=300999 so I think I'm ready to submit anything you may need.
Also page 23 of the service manual is showing the checking procedure for the symptom 'Power-Up Boot Fail', would this be right?

Checking the voltage on IC109 is a pain as it's tiny and has 48 pins.

Am I on the right path? Can the voltage testing be done when the TV is in a standby state as such the red led is on or would the readings be off?

I'm pretty noobish in regards to electronics so any help is appreciated. Also if anyone wants to slap me on the back of the head as I'm going about this the wrong way then feel free to do so.

Thanks.

[Caleb]

Re: LG 42PQ3000 No longer powering on?!

Service manual can be found HERE, You want isolation procedures on page 18,19 and also 23 I didnt find anywhere where it says the blinks mean any specific board.

[Jellzy]

Re: LG 42PQ3000 No longer powering on?!

Thanks Caleb, finally got a minute (stopped playing GTA... ) and managed to go through the procedures on page 18 and 19.

Beyond the fact that the LED's operating status colour is Blue instead of Green I think I've managed to do things right.

So page 18: B. Power Problem - No Power (Not turn on)

Power LED comes on flashes blue 6 times then goes solid blue for a minute before finally turning red - standby state.
From a standby state the remote is able to or rather attempts to power on the TV. This then follows the same procedure as above.
The IR on the remote doesn't seem to be an issue.
Checked the voltage reading on the pin from the P1100 adapter/connection from the Power Supply. I checked the following pins when the TV's LED was Blue and not when it was in a standby state. Also I checked them whilst the P1100 adapter was connected by reading from the top of the connector
RL_ON (Pin 19) = 3.26.
My 1st question is is this normal?

I went ahead and checked the rest anyway.

So P1100: (Pin)=(Voltage)

1=0
2=0
3=0
4=0
5=0.69
6=0.69
7=0
8=0
9=1.13
10=1.13
11=4.98
12=0.86
13=0
14=0
15=0
16=0
17=0.21
18=5.12
19=3.26
20=3.26
21=3.26
22=0
23=4.97
24=0.01

So again I'm not sure if these are normal or suspect but if my methodology in testing is wrong or if you'd like me to check them again then let me know... Also I ask as I don't have a clue what these readings mean.

So page 19: B. Power Problem - Turn off (Instant, under watching)

Following the 1st line as the 2nd doesn't apply. Attempting to turn on the TV after removing P1100 (Connector between Power Board and ZSUS/YSUS - Same thing?!) I get no LED at all.
I'm assuming that the strip along the bottom with the TV's controller inputs isn't getting any power at all.
According to the manual this mean I've to replace the Power Board?
Assuming I remove this connector then wouldn't it be case that the LED wouldn't come on as it has no means of getting power as the connector for the LED comes from the Main Board itself?
There is another connector to the Main Board via the the Power Board (PS B/D - XSUS (Board on the left) - Logic B/D - Main B/D). Would the LED get power from the Power B/D this way? Again I'm assuming not as it should then theoretically get power anyway but then that's why I stated above that of course it wouldn't get power as it's not connected.
Sorry if this doesn't make sense. Just ask if not and I'll try to clarify it a bit better.

So with that I've already done a bit of page 23 but after thinking about it again I realised that I'd check the voltages on the input connector on the main board (P1100) and not the output pins on the Power Supply itself (P813).
Would this matter much, and would the voltages be more accurate?
I didn't think it would so will take then again if need be as I'm not sure if the pins are wired up in the same order on both connectors so let me know.

So page 23: Power-Up Boot Fail

Check P1100 All Voltage Level (17V,5V) = See above. None measured anywhere near 17V but could this be due to my mistake of reading from the input rather than the output (again read above).
Check IC109 (pin29) Output Voltage Level (3.3V) = 0.03
Check L1103 Voltage Level 5V = 4.97
Check IC1105 (pin2) Voltage Level 3.3V = ? (Can't for the life of me find it).

Again there seems to be low voltages on many of the pins suggesting it is indeed the power board, but is it a case of the TV not fully powering up so the voltages wouldn't read full anyway (forgive my noobness and lack of anything electrical ).

Again everything was tested with my Multimeter at 20V, with the TV flashing in it's Blue state and not the red standby state.

Thanks again Caleb. Hopefully these details will proved some insight into my issue (or perhaps my lack of knowledge and understanding on the matter ).

[Caleb]

Re: LG 42PQ3000 No longer powering on?!

Ok, it looks like the power board may be the culprit. There may be more than one fault as well, but lets try to isolate the power board first. Can we please get well focused pictures of the front and back of the board resized to 2000 pixels longest side, pics of the whole back of the tv. It shouldn't matter as long as the connectors are in good contact if you measure from one side or the other. Also you can CAREFULLY check the voltage across the biggest capacitors with your multimeter, we're looking for about 400V so dont slip. Unfortunately the service manual does not have the power supply schematic, can we also get the number off your power board? Im assuming its a LG EAY60716801? Maybe someone can chime in here with a schematic

[Jellzy]

Re: LG 42PQ3000 No longer powering on?!

Right got a few photos using both my phone and the missus (HTC One + iphone5) as I wasn't sure about the quality.

https://plus.google.com/photos/11208...37051032403665

The biggest capacitors (2 Brown one's rated 450V) both measure at peak 382V i.e. as soon as the TV is attempting to power up. This rapidly decreases to between 250-260V in about a second or two before continuing to drop at a rate of about 10V every 5 seconds or so until the TV LED stops flashing.

The board model is eay58349601. Also on the board; PSPU-J808A, 2300KPG086B.

Thanks.

[Caleb]

Re: LG 42PQ3000 No longer powering on?!

Ok, so the good news is that the pfc appears to be working (the 382v). It seems to be shutting off after it tries to start and fails. I would test all the schottky diodes on the secondary side next, they typically have 3 legs and can be thought of as two diodes tied together with the cathode on the center pin. Test in diode mode on your multimeter, they are located on the heatsinks on the right side. Can we get the number off that 28 pin ic as well Your pics are still pretty blurry- I'm linking in the ShopJimmy pic of the front of the board for anyone looking at this post. ShopJimmy also lists 1 other power board that is supposed to be compatible, board number EAY58049801
That other ic (1105) may be on the back side of the board?

[Jellzy]

Re: LG 42PQ3000 No longer powering on?!

Aha back from a weekend away and ready to go again.

Yeah sorry for the pictures, unfortunately my camera broke so I'm left with mobile phone shots and the HTC One's lower res, 'larger' pixels doesn't sell itself to highly detailed shots.

Secondary side?

Are these Shcottky diodes like these?

http://static2.tme.eu/katalog_pics/6...3ctq100pbf.jpg

Also making sure I'm doing things right are the steps in this guide o.k.?

http://www.ehow.com/how_6920100_test...tky-diode.html

28 pin (IC701). MC80F0708. Seems to be a tonne on Google with different PSU revisions. Picture in the album.

https://plus.google.com/photos/11208...37051032403665

I guess making sure I get a reading is the aim of the game here?

Managed to find IC1105 on the main board, Measuring 3.29v.

[jurirevenge]

Re: LG 42PQ3000 No longer powering on?!

Solution : 6 times Blink blue LG 42PQ is change YSUS EAX60764001 or cheaper to solder IRGP4086

[jeff99]

Re: LG 42PQ3000 No longer powering on?! help

hi new to all this.my tv has the same issues. did you fix your tv and how . or do I change YSUS EAX60764001 for a new one and would this be the one with all the hdmi go in I think it about £50 for a new one.if you can help thanks

[mitarrazor]

Re: LG 42PQ3000 No longer powering on?!

Hi!
Could you please tell the value of
Q801 and Q906 ,they are missing from my Power board after sending tv to service ...and from Z-sus Q1 is missing too.
Thank you ! It will be very helpfull if you coud help me with this problem.
I'm sory for my english.
Have a nice day!

[Starrypotter]

Re: LG 42PQ3000 No longer powering on?!

Guys I have a similar issue with the same tv. Just constantly clicking with the red light flashing but never switching on. sometimes three, sometimes 15 clicks then shuts down with red light going off. It never goes blue. I am looking for a copy of the service manual if anybody can provide it.
Also. With multimeter should I be able to get readings to the outgoing DC connecters when it is shut down. Currently I get nothing apart from main incoming power connection.
Anyway thanks in advance, any help greatly appreciated.

[scorp82]

Re: LG 42PQ3000 No longer powering on?!

Solution : 6 times Blink blue LG 42PQ is change YSUS EAX60764001 or cheaper to solder IRGP4086

Hi, I have the same problem, I changed the IRGP4086, the tv worked for 3 days but no longer works again. Do you have other solutions? Sorry for my bad english, I'm french ...