Bad capacitor? on PS board of Sharp Aquos LCD TV LC-50LE442U

[ColoradoDale]

I would really appreciate help identifying the bad capacitor. The TV has had a problem not wanting to power on after shutting off. Found that if you unplug TV for a while, then sometimes it would power on. Eventually we just left TV on all the time for the past 2 weeks (screen saver would kick in) and there was no problem, till my wife accidentally shut it off. Now it refuses to come on. Only the green power LED comes on, nothing else happens and you have to unplug it to get the green LED to shut off.

Did some investigating and found a YouTube video discussing this exact same problem (same symptoms at least) on a Sharp Aquos LCD TV, and they showed the faulty capacitor that helps do a slow start power up. Well the model on the video was different and the power supply board on my TV looks totally different.

I am attaching a photo of my power supply board and hope someone can identify which might be the faulty capacitor (if that is the cause).

Thanks for any help you can give me.

-Dale

[zx8401]

Re: Bad capacitor? on PS board of Sharp Aquos LCD TV LC-50LE442U

Well ive found the small electrolitic capacitors on the primary side go low in value on some power supplys, you have 4 of them with black gloop holding them onto the pcb.
I would replace the one to the left and right of the top heatsink plate first, if you think its a startup capacitor.
Any capacitor near a heatsink tends to get cooked :-(

[ColoradoDale]

Re: Bad capacitor? on PS board of Sharp Aquos LCD TV LC-50LE442U

Thanks for the suggestion. I will give it a try.

[smartshah]

Re: Bad capacitor? on PS board of Sharp Aquos LCD TV LC-50LE442U

I have the same model and same problem.
I was not able to tell which one is bad as all of them look OK through visual inspection.
can you please let me know which capacitors did you replace to fix yours?

[budm]

Re: Bad capacitor? on PS board of Sharp Aquos LCD TV LC-50LE442U

Try those 4 caps first.
Bad caps can look normal, you need cap meter that can measure capacitance and the ESR.

http://www.shopjimmy.com/sharp-9jy09...pply-unit.htm#

[Michael Long]

Bad Barrier Rectifier on PS board of Sharp Aquos LCD TV LC-50LE442U

Related to the Sharp Aquos LCD TV LC-50LE442U... The TV in this case was DEAD no blinking lights and no response from the remote. All systems appeared dark.

The repair was accomplished by replacing the DM102 component. (MBRF20150CT) This sells on eBay as a Barrier Rectifier...

[Michael Long]

Re: Bad Barrier Rectifier on PS board of Sharp Aquos LCD TV LC-50LE442U

Image added...

[DaemonCross]

Re: Bad capacitor? on PS board of Sharp Aquos LCD TV LC-50LE442U

Well ive found the small electrolitic capacitors on the primary side go low in value on some power supplys, you have 4 of them with black gloop holding them onto the pcb.
I would replace the one to the left and right of the top heatsink plate first, if you think its a startup capacitor.
Any capacitor near a heatsink tends to get cooked :-(

How do you tell if its the start up caps that's acting up? As I have a similar issue with a monitor I'm working on (Newbie/Hobby) thats 50/50 chance to power on when you plug it in.