Sharp Aquos LC-46D85UN turns off by itself

[mr._mulligan]

I have a 10 year old Sharp Aquos LC-46D85UN that works for a few minutes, then it clicks and turns off. After it turns off, the OPC and the power LED blink twice together, then the OPC LED alone blinks a third time.

Sometimes, the TV would work fine for 30 minutes before this happens. After it happened once, it keeps happening after a shorter period of time.

Any clues on how to diagnose the problem? Any help would be greatly appreciated! Thanks!

[dick_barton]

Re: Sharp Aquos LC-46D85UN turns off by itself

Is this set a fluorescent backlight set? If it is then after 10 years it may well be that one or more of the tubes are failing when warmed up.

Look very carefully at the screen and see if there is a slightly darker line across the screen where perhaps a tube is failing.

Of course it could be one of any number of other problems so this is just a suggestion.

[mr._mulligan]

Re: Sharp Aquos LC-46D85UN turns off by itself

Is this set a fluorescent backlight set? If it is then after 10 years it may well be that one or more of the tubes are failing when warmed up.

Look very carefully at the screen and see if there is a slightly darker line across the screen where perhaps a tube is failing.

Of course it could be one of any number of other problems so this is just a suggestion.

Hi, thank you for the reply. I looked really closely, and the picture looks perfect. I do recall that, before this problem start, I was thinking, the screen seems really hot. I felt the heat when standing a couple of feet away. I thought that was just normal, but I couldn't recall noticing that before.

[budm]

Re: Sharp Aquos LC-46D85UN turns off by itself

Try turning down backlights level (not brightness) on all input modes to as low as possible to see if the TV will stay working longer.

[jostewcrew]

Re: Sharp Aquos LC-46D85UN turns off by itself

Power failure details (Power LED flashes twice and OPC LED flashes)
DET_3V3 (pin 64): Abnormal (L). Main power 3.3V is not applied
If error is detected during operation, error standby is activated by polling

[mr._mulligan]

Re: Sharp Aquos LC-46D85UN turns off by itself

Thanks for the replies. I'll go about trying various things. Fortunately, I have other TVs, so this isn't time sensitive. So, I can take my time. Just hate to throw away something if it can be salvaged.

[nomoresonys]

Re: Sharp Aquos LC-46D85UN turns off by itself

A little test, turn it on when it acts up heat the inverter/balance boards whatever you want to call them with a hairdryer be sure to heat the 6 electrolytic capacitors, see if the tv comes back on.

[nomoresonys]

Re: Sharp Aquos LC-46D85UN turns off by itself

There's a way to measure the transformers on the inverter/balance boards, not sure how it's done on this one, maybe one of the resident gurus knows, can also check youtube, if one shows a big difference when tested it points to a ccfl backlight as suggested or one of those transformers probably being the issue.

[mr._mulligan]

Re: Sharp Aquos LC-46D85UN turns off by itself

A little test, turn it on when it acts up heat the inverter/balance boards whatever you want to call them with a hairdryer be sure to heat the 6 electrolytic capacitors, see if the tv comes back on.

Are you saying that heating up the capacitors might make it stay on?

[nomoresonys]

Re: Sharp Aquos LC-46D85UN turns off by itself

It's just a little test that may lower the esr in a faulty capacitor for a very short time and make the tv work for a minute, then you know you have bad capacitor/s, there's other ways of checking caps with esr meter, some multimeters have esr/capacitance built in, another test is WITH TV UNPLUGGED from power, set meter to 20k on ohm mode, put neg - probe on neg - leg of capacitor and pos + probe on pos leg watch meter it should gradually increase if it's charging correctly, keep in mind that doesn't necessarily mean the esr is good.