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LG 42cs570 shuts off after 10 seconds of powering on.

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jts1957
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Oct 12, 2015, 1:11 AM

Post #26 of 49 (2976 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

http://www.shopjimmy.com/...cklight-inverter.htm FOIL view - upper left quadrant - 28 pin surface mount IC. If illegible, clean with a rubbing alcohol (NO harsher) dampened Q-tip, let evaporate and try to make out part number(s).

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Location: Far, Far Away

davisflow
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Oct 12, 2015, 2:46 AM

Post #27 of 49 (2974 views)
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Re: [jts1957] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

So on the board, it is actually a 24 pin chip. The number is.

BD9270F
217 k75

(I am pretty certain that the second number/letter is a D, however, there is an of chance that it is a poorly printed 0.)

jts1957
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Oct 12, 2015, 7:09 AM

Post #28 of 49 (2963 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

When coming to shop jimmy via a google search of TV model number, three power supplies are listed. The one you gave part number of plus two others. The chip number you rattled off IS being used by the two boards that do NOT match your board number. Something is off. I don't know if SJ may have mixed up their photos, but although I can't make out markings on the chip on the correct part number board, I CAN make out that it DOES have 28 pins (BD9240 presumably). I'll pull datasheet for your BD9270.

The fuse next to the two inverter transformers is good? Also check the 4 FETs (on heat sink above and to the right of fuse/xfmrs) for shorts.

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Location: Far, Far Away

(This post was edited by jts1957 on Oct 12, 2015, 7:48 AM)

davisflow
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Oct 12, 2015, 8:45 AM

Post #29 of 49 (2957 views)
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Re: [jts1957] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

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Ya, something is off, my guess is that they have a revised board they want me to install rather than the original, for whatever reason. When I called LG and asked which power/inverter board I should buy, they told me "EAY62770801" at http://lge.andrewselectronics.com/search/electronic-parts/parts/9/EAY62770801 , which is the pic on SJ with 28 pins btw.

The number on the actual power/inverter board in my set right now is EAX61124201/16. But, I couldn't find this online for sale, which is why I called LG.

I work the next 3 nights, again, so I won't be able to run any tests until Thurs afternoon : (

(This post was edited by davisflow on Oct 12, 2015, 8:46 AM)

davisflow
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Oct 15, 2015, 11:11 PM

Post #30 of 49 (2933 views)
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Re: [jts1957] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

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The fuse next to the two inverter transformers is good?

Yes it is, the other fuse on the board is also good. (no open loop reading when I test them.)

Quote

Also check the 4 FETs (on heat sink above and to the right of fuse/xfmrs) for shorts.

Not sure how to test these, I have located them on the heat sink you mentioned, and youtubed some videos on testing these, but am having difficulty in determining if I am turning the gate on or off...also, the angle is poor from the top of the board, so I have the p201 cable unplugged, and the board turned foil side up. Can you give me some direction here please?

jts1957
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Oct 15, 2015, 11:44 PM

Post #31 of 49 (2929 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

Set unpowered. Whole board or plug 201 connected or not. Board right side up or upside down.

Fuse: Meter function on ohms - meter range on a low scale. Meter leads apart display should indicate over-range ... meter leads touching should equal ZERO. One meter lead on one side of a fuse, the other meter lead on the other end of the same fuse should equal ZERO. No hesitation, No waiting for reading to stabilize, no uppity-up.

1 * * 2

`3 *

You're testing for ZERO (or very low readings) In Circuit - NOT for function. Three pins (*) - two meter leads = 6 tests (if meter has a 'diode' test function set it to that).
1) Red on 1 & Black on 2
2) Black on 1 & Red on 2
3) Black on 3 & Red on 1
4) Black on 3 & Red on 2
5) Red on 3 & Black on 1
6) Red on 3 & Black on 2

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Location: Far, Far Away

(This post was edited by jts1957 on Oct 15, 2015, 11:46 PM)

davisflow
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Oct 16, 2015, 12:32 AM

Post #32 of 49 (2924 views)
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Re: [jts1957] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

Thanks for the help with this part.

Quote

Fuse: Meter function on ohms - meter range on a low scale. Meter leads apart display should indicate over-range ... meter leads touching should equal ZERO. One meter lead on one side of a fuse, the other meter lead on the other end of the same fuse should equal ZERO. No hesitation, No waiting for reading to stabilize, no uppity-up.

For the fuse, the reading is 000.5, which is the same as if I have the meter leads touching.

Quote

You're testing for ZERO (or very low readings) In Circuit - NOT for function. Three pins (*) - two meter leads = 6 tests (if meter has a 'diode' test function set it to that).
1) Red on 1 & Black on 2
2) Black on 1 & Red on 2
3) Black on 3 & Red on 1
4) Black on 3 & Red on 2
5) Red on 3 & Black on 1
6) Red on 3 & Black on 2

Meter is a Fluke 87 with diode function.
Using the foil side picture from shopjimmy as orientation, the four FETs are now top middle of the board, with an upward pointing arrow-shape cutout in the board, separating 1 and 2 from 3, as indicated in your post. Going from left to right.

FET #1
1) Red on 1 & Black on 2 0.154
2) Black on 1 & Red on 2 0.154
3) Black on 3 & Red on 1 0.427
4) Black on 3 & Red on 2 0.562
5) Red on 3 & Black on 1 .OL
6) Red on 3 & Black on 2 .OL

FET #2
1) Red on 1 & Black on 2 0.154
2) Black on 1 & Red on 2 0.154
3) Black on 3 & Red on 1 0.427
4) Black on 3 & Red on 2 0.562
5) Red on 3 & Black on 1 .OL
6) Red on 3 & Black on 2 .OL

FET#3
1) Red on 1 & Black on 2 0.154
2) Black on 1 & Red on 2 0.154
3) Black on 3 & Red on 1 0.427
4) Black on 3 & Red on 2 0.562
5) Red on 3 & Black on 1 .OL
6) Red on 3 & Black on 2 .OL

FET#4
1) Red on 1 & Black on 2 0.155
2) Black on 1 & Red on 2 0.155
3) Black on 3 & Red on 1 0.428
4) Black on 3 & Red on 2 0.564
5) Red on 3 & Black on 1 .OL
6) Red on 3 & Black on 2 .OL

jts1957
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Oct 16, 2015, 1:26 PM

Post #33 of 49 (2899 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

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The number on the actual power/inverter board in my set right now is EAX61124201/16. But, I couldn't find this online for sale, which is why I called LG.

On the Shop Jimmy IP pictures, they show a barcode sticker with a portion of the number highlighted. What is this number on your TVs board? This explains the 24 vs. 28 pin IC difference.

Comparative readings indicate the four FETs are likely the same part / same circuit.
You may want to try comparative readings of the two transformers and ONLY report if has a major discrepancy from one to the other. Looks like two pins for primary and two other pins for secondary. I'd unplug wires that lead to lamps, put your meter on ohms (it should have auto ranging) and measure primaries (pins closest to the board centerline - note they are wired in series) and then the secondaries (pins closest to bulb plug connectors).

-------------------------
Location: Far, Far Away

davisflow
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Oct 16, 2015, 6:24 PM

Post #34 of 49 (2892 views)
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On the Shop Jimmy IP pictures, they show a barcode sticker with a portion of the number highlighted. What is this number on your TVs board?

The number is LC7R2600694075362(1.5)

Quote

You may want to try comparative readings of the two transformers and ONLY report if has a major discrepancy from one to the other. Looks like two pins for primary and two other pins for secondary. I'd unplug wires that lead to lamps, put your meter on ohms (it should have auto ranging) and measure primaries (pins closest to the board centerline - note they are wired in series) and then the secondaries (pins closest to bulb plug connectors).

Orienting the board as seen in the foil-side picture. There are two sets of 4 pins, (from the far right edge of the board and going to the left), , one set above the 'input-output chart and one set below.

____________________________

Top row 1 2 3 4

(input-output chart)

Bottom row 5 6 7 8
____________________________

Primaries, closest to board centerline:
-Between 5,6,7,8. No discrepancy.
(All are 000.8(or very close to it); this is regardless of where the red or black probe is placed, and in
all possible combinations.)

Secondaries, closest to bulb plug connectors)
-Between 1-2; and between 3-4. No discrepancy. (18.3 for both)

Were these the measurements you were asking for?

jts1957
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Oct 16, 2015, 7:31 PM

Post #35 of 49 (2883 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

Are both those resistances in 'ohms?' From my days doing computer monitors, one winding should be damn low, which you report as low. The other winding was usually in the hundreds to low thousands of ohms, but these transformers were smaller in size and more transformers in numbers.

The number is LC7R2600694075362(1.5)
There IS a board at SJ: 60869407.

Unfortunately neither version of above jives with the board you claim is in the set, nor the one they'd like to sell you.

If Error is low when screen is on (lit), what happens if you were to keep it low with a third jumper, Error to ground? You would want to be able to see a single color screen if the screen stays on for more than a couple of seconds, to see if any area is dimmer than any other.

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Location: Far, Far Away

davisflow
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Oct 16, 2015, 7:50 PM

Post #36 of 49 (2879 views)
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Re: [jts1957] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

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Are both those resistances in 'ohms?'

Yes, both were in ohms.

My mistake: The board number I have is: LC7R2608694075362(1.5)

Quote

If Error is low when screen is on (lit), what happens if you were to keep it low with a third jumper, Error to ground? You would want to be able to see a single color screen if the screen stays on for more than a couple of seconds, to see if any area is dimmer than any other.

I will try this now.

jts1957
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Oct 16, 2015, 8:26 PM

Post #37 of 49 (2875 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

How many different part numbered boards have been installed in the set?
This should be your board - Note your wrong Part Number.
http://www.shopjimmy.com/...wer-supply-unit.htm#

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Location: Far, Far Away

(This post was edited by jts1957 on Oct 16, 2015, 8:40 PM)

davisflow
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Oct 16, 2015, 8:55 PM

Post #38 of 49 (2873 views)
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If Error is low when screen is on (lit), what happens if you were to keep it low with a third jumper, Error to ground?

When I attach a jumper from error to ground(no other jumpers), with the cable plugged in, and turn the set on, it shows the main screen, then the screen turns off, but the power light stays lit, blue, indicating that power is on. If I hit the 'input' button on the remote, the blue light flashes indicating that it is receiving the signal.
The set did not shut of automatically, I had to press the power button on the remote to turn it off. When I turned it back on, and the screen flashes on again, it was on a different input, indicating that when I pressed 'input' while the blue power light was on, the signal was received.

Quote

You would want to be able to see a single color screen if the screen stays on for more than a couple of seconds, to see if any area is dimmer than any other.

I can't get the screen to stay on for more than 1 second, however, I took a close look at it a few times, and I do not see any dim areas.

davisflow
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Oct 16, 2015, 8:57 PM

Post #39 of 49 (2872 views)
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How many different part numbered boards have been installed in the set?
This should be your board - Note your wrong Part Number.
http://www.shopjimmy.com/...wer-supply-unit.htm#

Not following you here, the only board that is in the set is the board that came with it. I do not have any spares or backups; and I have not purchased one yet.

jts1957
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Oct 16, 2015, 9:32 PM

Post #40 of 49 (2865 views)
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In Reply To

Quote

How many different part numbered boards have been installed in the set?
This should be your board - Note your wrong Part Number.
http://www.shopjimmy.com/...wer-supply-unit.htm#

Not following you here, the only board that is in the set is the board that came with it. I do not have any spares or backups; and I have not purchased one yet.

http://imgur.com/uy7ld6q

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Location: Far, Far Away

jts1957
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Oct 16, 2015, 9:41 PM

Post #41 of 49 (2862 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

If you expect to use power LED, keyboard, remote buttons, inputs or tuner, then main to IP cable MUST remain connected.

I need you to use all three jumpers simultaneously. If you can only do this with that cable disconnected, the best you can hope for is a blank white screen. No video - No audio - No blue power light to guide you considering the keyboard buttons and remote control receiver won't be working. We are looking to see if screen remains lit longer than a second or two.

-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on Oct 16, 2015, 9:45 PM)

davisflow
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Oct 16, 2015, 9:41 PM

Post #42 of 49 (2861 views)
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http://imgur.com/uy7ld6q

Yes, when I look at the pics of that on shopjimmy, and when I compare the numbers you highlighted with the board in my set, they match, it is the same board that is installed.

You think it's worth a shot replacing the board?

(This post was edited by davisflow on Oct 16, 2015, 10:21 PM)

davisflow
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Oct 16, 2015, 9:41 PM

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jts1957
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Oct 16, 2015, 9:51 PM

Post #44 of 49 (2857 views)
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Look in the upper right corner of each of your posts. There should be four choices, the first being 'Edit."

Quote

You think it's worth a shot replacing the board?

IF the screen remains lit while all three jumpers are in place, then bulb(s)/panel should be ruled out..

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Location: Far, Far Away

(This post was edited by jts1957 on Oct 16, 2015, 9:51 PM)

davisflow
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Oct 16, 2015, 10:26 PM

Post #45 of 49 (2843 views)
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I need you to use all three jumpers simultaneously. If you can only do this with that cable disconnected, the best you can hope for is a blank white screen. No video - No audio - No blue power light to guide you considering the keyboard buttons and remote control receiver won't be working. We are looking to see if screen remains lit longer than a second or two.
_______________________________________________________

IF the screen remains lit while all three jumpers are in place, then bulb(s)/panel should be ruled out.

I was able to try this out with all three jumpers, and with the cable disconnected, the screen flashed on and off in about 1 second; it did not stay lit.

I can *try* to get the jumpers in place with the cable connected, not sure I can do it, would you consider it to be worth trying, in light of
the failed test with all three jumpers and the cable disconnected?

_______________________________________________________
_______________________________________________________
UPDATE

I have now successfully placed all three jumpers, with the cable connected; screen on for 1 second, then off, but blue power light remains lit, and flashes in response to the remote control.

So, bulb panel not ruled out, but power supply also not ruled out, is it a toss-up between those two at this point?

(This post was edited by davisflow on Oct 16, 2015, 11:37 PM)

jts1957
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Oct 17, 2015, 12:09 AM

Post #46 of 49 (2827 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

Power Supply AND Inverter share ONE board. Power Supply portion is ruled out. Inverter portion is NOT ruled out.

Replacing panel would not be economical. If you want to risk it, try the IP board. There are other things that could be tested (like does b-plus to FETs stay or go with screen and backlight driver IC pins voltages and possible bypass).

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Location: Far, Far Away

(This post was edited by jts1957 on Oct 17, 2015, 12:10 AM)

davisflow
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Oct 20, 2015, 6:23 AM

Post #47 of 49 (2807 views)
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Power Supply AND Inverter share ONE board

Quote

'
Yup, I'm aware of that, I have purchased the board, thanks for helping me isolate the problem to the IP board or the bulbs/panel. I will post back here letting you, and whoever else may read this in the future, if the new IP board solves the problem.

btw, in the event that you may not be aware, and in the event that your real life interaction is similar to your online interaction, two big ifs, you come across as moderately rude and abrasive, at least during this encounter with me; BUT, with that said, thanks for your time and assistance, I do appreciate it, really.

jts1957
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Oct 20, 2015, 11:38 AM

Post #48 of 49 (2805 views)
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Re: [davisflow] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

'Its in my nature,' and here I was going for soft and cuddly. Tongue

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Location: Far, Far Away

davisflow
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Oct 26, 2015, 8:25 PM

Post #49 of 49 (2797 views)
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Re: [jts1957] LG 42cs570 shuts off after 10 seconds of powering on. [In reply to]	Can't Post

haha

I just installed the power supply/inverter board and the set now works!!

Again, thank you for the help, and hopefully this thread will be useful to someone else.

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