this set was given to me and only has about 4 or 5 months use.It shut down and has no video or audio as well as no indicator lights ie stand-by pwr etc.It appears to be dead but the main pwr switch is good and there is pwr to the main board.I'm a novice as far as electronics are concerned but I am of average intelligence to try to decipher what you will reply.Thanks for any help on this matter.
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Re: 37lh20-ua lcd tv
If it's 4 or 5 months old, contact LG. They should replace it or repair it. It's not your job to fix something like that under 12 months old!Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search. -
Re: 37lh20-ua lcd tv
LG manuf. date is March 2010 but was only used about 4 or 5 months.Comment
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Re: 37lh20-ua lcd tv
Ron77
On the psu there should be a plug socket going to main board. I know that on model LG 37lh2000za this socket is top right of psu.The voltages should be written to the right of the socket. In standby and on mode, the 5.2v is on all the time.This is the standby supply. When set is on 12v 20v and 3.8v appear.These voltages are switched on by the p-on voltage which comes from the main board.This voltage is 5v app.I should have mentioned the 3.8v is the invertor on voltage and comes from the main board.Check the 5.2v going to main board.If 5.2v is going to main board and no standby light then the main board could be faulty.What I have outlined is how the LG37lh2000za works,is it similar to yours, I don't know.In any event without the 5v standby you will have a pretty lifeless set. Bad capacitors can cause the loss of stb supply. Faulty capacitors in psu can cause problems in the main board, namely the main chip in chip Ic. Not widespread, but I have known it happen on a certain model after about two years six months, the manufacturer did repair them for free.It never hurts to check capacitors, but that may not be the problem with your set.Comment
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Re: 37lh20-ua lcd tv
We can often help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.
Please do not post inline and offsite as they slow down the loading of pages.
Examples of what is needed
https://www.badcaps.net/forum/attach...7&d=1280167246
https://www.badcaps.net/forum/attach...6&d=1280167246
https://www.badcaps.net/forum/attach...4&d=1280167246
It will be useful if you can say a bit about yourself - skills tools etc.Please upload pictures using attachment function when ask for help on the repair
http://www.badcaps.net/forum/showthread.php?t=39740Comment
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Re: 37lh20-ua lcd tv
I'm a rookie, but I will say this... I've just revived a 55" LCD and a 37" LCD with a hair dryer. It's worth a try... Heat up all of the caps on the secondary side and try to fire it up.
But as stated already, check that you have standby first. Have you tested the main AC fuse?Last edited by martyparish; 01-28-2013, 07:36 AM.Comment
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Re: 37lh20-ua lcd tv
I hope someone can give me some input on this problem.I have a 37" lg lcd tv manu date 03/2010 mod#37lh20-ua it only has about 4 or 5 months use and was given to me after the owner was watching it it just blacked out as if you had pulled the pwr plug-no stand by lights or audio just dead.I don't have the money for a new tv or to pay to have this fixed so I figured I'd see if I could fix it myself as my friend said keep it if you can fix it.I took the back off and checked it out.I'm not an electronic guru and have minimal electronic knowledge but it's worth a shot and I understand this forum has a good bunch of guys that might be able to help me.What I found was this:The main pwr switch is good and there was power to the main board.but I found a 250v/3a fuse blown it's the one right behind the 2 plugs-one from the pwr cord block and the other looks as if it is from the remote sensor assy.I bought a new pigtail fuse and soldered it in and plugged in the power cord and as soon as I pushed the pwr rocker switch on it blew the new fuse.Anyone who may have some helpful knowledge on this I welcome your input.Thank you in advance,Dan/poolshark.Comment
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Re: 37lh20-ua lcd tv
Please read selldoor's post and supply pictures - we can then help locate potential test points...Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: 37lh20-ua lcd tv
here is the pwr board with the blown 3a/250v fuse circled.Attached FilesComment
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Re: 37lh20-ua lcd tv
Re-read Selldoor's post. There's something in there about clear photos. Remember, we do not have this board in front of us. The pictures are our eyes.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: 37lh20-ua lcd tv
OK, the replacement board is about $42 on EBAY, by the time you have to replace what is/are shorted out (MOSFET's, rectifier, blown resistors, IC. etc.), you can easily spend $20 on the parts more or less if you want to troubleshoot it down to component level. Something for you to think about.
http://www.ebay.com/itm/LG-EAY576810...-/251151078136Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: 37lh20-ua lcd tv
here is a larger hopefully clearer picture of the power board with the blown fuse I replaced and it blew as soon as powered up.Attached FilesComment
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Re: 37lh20-ua lcd tv
Not clear pictures, cannot read the printing of the designators of the parts, labels of the connectors, also need CLEAR and FOCUS of the whole back side and four 1/4 section of the board so we can trace the connection to be able to give you the test points.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: 37lh20-ua lcd tv
Here is a simple test.
I took your "clearer" picture and put a red box around. Without looking at your physical board and looking only at the picture I re-uploaded (with no changes in resolution), please list the writing inside that red box.
Now do you understand what we have to work with?Attached Files--- begin sig file ---
If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.
We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.
Please do not post inline and offsite as they slow down the loading of pages.
--- end sig file ---Comment
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Re: 37lh20-ua lcd tv
By the way, do you have the tools to do component level repair?Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: 37lh20-ua lcd tv
BTW, all the pictures in selldoor's post #5 were taken by me so I "walk the talk".--- begin sig file ---
If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.
We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.
Please do not post inline and offsite as they slow down the loading of pages.
--- end sig file ---Comment
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Re: 37lh20-ua lcd tv
Necesito el manual de servico del TV LG 37LH20, por favor quien pudiera ayudarmeComment
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Re: 37lh20-ua lcd tv
I need services manual TV LG 37LH20, pleaceComment
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Re: 37lh20-ua lcd tv
I need services manual TV LG 37LH20, pleaseComment
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Re: 37lh20-ua lcd tv
For eduardo.m:
You can find the manual here: http://www.lg.com/us/support-product/lg-37LH20Comment
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Hi guys,
its been around 5-6months since i left this board on side to rest my brain cells and now came back to try and repair it again.
The laptop in question has issue where it gives error code on power on which is 2red and 3 blue
In short, by Dell specs this means "Memory not detected: "
Now one important thing the laptop would turn on fine when i leave it in the refrigerator for 5-10min and i could work\play games with it for days and months as long as i dont turn it off
but after a while this trick stopped working as wel
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In recent months the screen has been getting more and more dim. If that was all, I'd suppose the problem would be the backlight (LED? LCD?). But I've noticed this really weird symptom: switching to the EPG screen restores normal brightness! And then, even weirder, when I go back to the programme, for a moment the programme is at normal brightness and over the next 1-2 seconds it gradually dims down again.
Last time I looked in a TV it had EHT flyback, so I'm no expert. I do sometimes repair computer monitors and power supplies, most often when there's bad caps.
Anyhow,... -
Problem description:
My UPS requires new batteries every ~3 months; in this time frame, an average of about 5 to 10 power flickers or short power interruptions (< 2 minutes) occur. After an average of 3 months, a new pair of batteries begins to fail to keep the UPS up during any flicker or power interruption. The load it powers is a single computer/workstation running 24/7 with a continuous consumption between 200W to 300W.
UPS model:
The Atlantis 1001 is a non-inexpensive (~120€ back then) home/office offline UPS, rated 1000VA, 600W, designed for two 7Ah... -
I couldn't find any other thread that matches my TV problem but have been told it is a common fault. The fault is a flashing LED as if it is in upgrade mode that happens after a few seconds and stays forever. I can't remember all the tricks that have been tried like holding the select button when powering on but nothing worked. The shop sent me a flash drive to plug in a USB port but that did nothing either and they said it was dead which is disgusting for a piece of solid state electronics. I took the back off eventually after removing 34 screws to check for blown caps but everything looks new... -
My T14's (NM-C801) main USBC input keeps failing every few months. Initially, it worked fine for several years. The symptom is that once powered from the main USBC port using a 65W power brick, after some time (minutes, hours) charging will fail completely. Powering from the secondary (docking) USBC input still works. This laptop is basically always plugged in. The first time it happened, it took me a long time to find that the FPF2281 over-voltage IC for that USBC input was at fault. When the issue occurs, it will continuously reset power delivery negotiations with the power brick -- according...
Comment