Sharp PN-LE701 turns itself on

[TVnovice2]

I have a PN-LE701 that turns itself back on almost exactly 65 seconds after being turned off. I have done a hard reset, factory reset and updated the firmware by USB, all to no avail. I called Sharp and they said they have experienced this quite a few times and just replaced the main board. Once, a factory reset corrected the problem but only once. Any help appreciated.

[dskall]

Re: Sharp PN-LE701 turns itself on

Have you taken batteries out of remote?

[nomoresonys]

Re: Sharp PN-LE701 turns itself on

if none of the usual works, look over the solder joints on powerboard very closely, resolder any that look a little suspect being careful not to bridge anything, maybe also suspect the start up capacitors by the connector on powerboard where the cable from powerboard to mainboard is located, example of bad solder joints there in case anyone needs it: https://www.google.com/search?q=bad+...ih=607&dpr=1.5

[TVnovice2]

Re: Sharp PN-LE701 turns itself on

Yes, I even turned off the TV, unplugged the cable from the buttons and remote and it still turned itself on.

[TVnovice2]

Re: Sharp PN-LE701 turns itself on

I thought it could be the PS. I had a Vizio that would turn itself off and a new PS solved that but hte the sharp technicians said that only changing the Main board solves the problem- if you have 200 bucks to waste on a main board. Thanks

[dskall]

Re: Sharp PN-LE701 turns itself on

And you're sure your timer has not been set.

[lotas]

Re: Sharp PN-LE701 turns itself on

But if he did a hard reset, reset to factory settings and updated the firmware via USB, then the timer is unlikely to be saved.

[dskall]

Re: Sharp PN-LE701 turns itself on

But if he did a hard reset, reset to factory settings and updated the firmware via USB, then the timer is unlikely to be saved.

Probably. Just throwing things out to try. Seems strange it comes on in the same time each time.

[TVnovice2]

Re: Sharp PN-LE701 turns itself on

I appreciate any thoughts. Thanks

[nomoresonys]

Re: Sharp PN-LE701 turns itself on

when I have encountered such symptoms, most every time the powerboard was the culprit.

[dskall]

Re: Sharp PN-LE701 turns itself on

You might try heating processor and see if anything changes.

[TVnovice2]

Re: Sharp PN-LE701 turns itself on

I had it tested in another PN-701 and the same thing happened so its not the PS.

[TVnovice2]

Re: Sharp PN-LE701 turns itself on

It's something to do with software, probably a bad NAND chip.

[nomoresonys]

Re: Sharp PN-LE701 turns itself on

well then you solved your own riddle, choices are buy another mainboard, program a new nand chip or buy one already programmed if available.

[TVnovice2]

Re: Sharp PN-LE701 turns itself on

Well we got fooled. When the problem first appeared we changed the NAND chip and that did not solve the problem so after much thought and testing we found the "new" NAND was not working and replaced it with another new chip which solved the problem.

[nomoresonys]

Re: Sharp PN-LE701 turns itself on

ok, thanks for the followup.

[rayliu11]

Re: Sharp PN-LE701 turns itself on

Well we got fooled. When the problem first appeared we changed the NAND chip and that did not solve the problem so after much thought and testing we found the "new" NAND was not working and replaced it with another new chip which solved the problem.

How did you replace and program the NAND chip? Did you just solder on a blank NAND chip and flash the firmware?

Thanks!