Sharp TV Dead

[Stu jaxon]

Hi Group, can someone help please.? im working on a sharp TV model lc-65le643u. he said it went dead when watching.. i plugged it in, no power, no standby light. I checked the fuse, has good continuity. no voltage on standby pin.. visual check on components, nothing obvious.. should i change the ps board.?

[ohg...@gmail.com]

On Thursday, March 24, 2022 at 4:09:55 PM UTC-4, Stu jaxon wrote:
> Hi Group, can someone help please.? im working on a sharp TV model lc-65le643u. he said it went dead when watching.. i plugged it in, no power, no standby light. I checked the fuse, has good continuity. no voltage on standby pin.. visual check on components, nothing obvious.. should i change the ps board.?

Check the DC voltage across either of the 82/450 caps. There should be at least 160VDC in standby (about 375VDC if the supply is commanded on from the main) as long as AC power is applied. If that bridge voltage isn't there, look for a shorted transistor under the heatsinks and an open low ohm resistor. If the voltage is there, unplug the main board from the power supply and recheck your standby voltage. There should be at least 10 volts (could be 19V). If it's missing with the main board unplugged, you have a bad power supply. Repair or replace.

If the standby voltage returns with the main disconnected, your main is loading down the standby supply - repair or replace.

[Stephen Wolstenholme]

On Thu, 24 Mar 2022 13:09:53 -0700 (PDT), Stu jaxon
<stankow...@gmail.com> wrote:

>Hi Group, can someone help please.? im working on a sharp TV model lc-65le643u. he said it went dead when watching.. i plugged it in, no power, no standby light. I checked the fuse, has good continuity. no voltage on standby pin.. visual check on components, nothing obvious.. should i change the ps board.?

A factory reset fixed my Sharp TV. I didn't see how it was done but it
was not using the remote. I think it was using the buttons on the back
at the top.

Steve

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[Stu jaxon]

an ic 8 pin exploded with a cracked smd cap. board part # up17 ic fr9889 8 pin.. these boards are hard to find.. out of stock

[ohg...@gmail.com]

[ohg...@gmail.com]

On Friday, March 25, 2022 at 4:16:40 PM UTC-4, Stu jaxon wrote:

I might have that IC. If you're comfortable doing SMD work, that would be your best option. Don't just change the IC - check the secondary rectifier (usually a Shottkey) and look for a shorted zener and a shorted driver IC. I'll check Monday when I get to work.

[ohg...@gmail.com]

There's a complete board on ebay for like $25...

[Stu jaxon]

OK,..

[Stu jaxon]

[Stu jaxon]

Can you send me the link, I've searching for two days now, haven't found anything.. especially that cheap.??

[ohg...@gmail.com]

https://www.ebay.com/itm/313662376833?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=313662376833&targetid=1492398649899&device=c&mktype=&googleloc=9003391&poi=&campaignid=15434361728&mkgroupid=138918423308&rlsatarget=pla-1492398649899&abcId=9300764&merchantid=8338234

That number crosses to your board. Check the numbers and see if it fits. According to my info, that is your correct sub.

[Stu jaxon]

Thanks, but that was a PS board, sorry, i didn't mention it, but the ic blew on the main/logic board... #3665-0062-0150(2A)..

[ohg...@gmail.com]

If you unplug the main board, your standby voltage should return. If it doesn't, you now have problems on *two* boards, probably from a lightning hit. Those small DC regulators on the main can and do fail, but my experience is that a regulator IC on a Sharp/AmTran main board won't explode without being pounded by a surge. At that point, you should put it aside and troll around for a local unit with a broken screen and good donor boards.

Main boards on these Sharps are hard to find because people grab them thinking they will fix their blinking front LED issue, which are more often than not due to back light LED failures in the display than a bad main. Put yourself on a waiting list at ScrapJimmy. At least if the board is bad, they replace or refund with no hassle.

[three_jeeps]

On Saturday, March 26, 2022 at 11:08:56 AM UTC-4, ohg...@gmail.com wrote:
snip

>
> Main boards on these Sharps are hard to find because people grab them thinking they will fix their blinking front LED issue, which are more often than not due to back light LED failures in the display than a bad main. Put yourself on a waiting list at ScrapJimmy. At least if the board is bad, they replace or refund with no hassle.

I googled ScrapJimmy but 3 pages of hits turned up nothing about electronics. Can you please post a link?
Thanks
J

[ohg...@gmail.com]

Those of us in the trade use that name a bit derisively. Their name is ShopJimmy. They sell TV parts, but none of them are tested. Sometimes we've had to send the same board back three times until a working example was acquired. The good thing about ShopJimmy is that they are very good about replacing defective parts.

[Three Jeeps]

Thank you,
My dad was in the trade for ~ 50+ years till 2000. I spent a fair amount of time in his shop and going on service calls. My schooling and interests in electronics took me in a different direction, but I learned quite a bit about repair service work for most things electronic. One of them was knowing where to go for replacement parts. This was in the days of catalogs and phone calls.