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.
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
On Saturday, March 26, 2022 at 11:08:56 AM UTC-4, snipped-for-privacy@gmail.com wrote: snip
I googled ScrapJimmy but 3 pages of hits turned up nothing about electronics. Can you please post a link? Thanks J
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.
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.
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