Sharp LC-40LE810UN question

[mp3car]

Re: Sharp LC-40LE810UN question

I am new to the board... I have a 70LE650U that was just given to me by a neighbor... I am an EE, so I'm not a noob when it comes to electronics tinkering...

Before I go into too much of the details of what the unit is (and isn't) doing, should I continue this thread, since it is "currently" giving me a 2-5 code, or should I start a new thread since this one is quite old? I say "currently" because it's now showing a slightly different behavior than the first day I got it. It was working, but after 10 minutes it had "dark" or "shadowed" horizontal bands. I took the cover off, the main chip on the t-con board was extremely hot. I turned it off, let it cool a little bit, turned it back on, now only 5 minutes in and it got the bands. I "manually" cooled the chip and it ran for a good 20 minutes or so. However, the next day, now the backlight only comes on for a few seconds, then goes dark, and shows a 2 long 5 short code.

Anyhow, if a moderator would please reply (or PM me) to weigh in on whether i should start a new thread, or make this 14-page thread even longer by adding my issue - I'm thinking a new thread, but referencing this thread, is probably the way to go...

[ijohannessen]

Re: Sharp LC-40LE810UN question

Hi,
I have followed this thread with great interest. I have a LC-60LE810UN that won't start up, it only has Standby signal(BU5V) on the PSU. Inverted V flashes 1-1 on power up. PW_ON never goes high. The detailed flash code is also 1-1(Lamp error). As a side note, I get the 2-5 flash code if I disconnect the T-CON board(ribbon or power cable).
Before I give up on this set, I'd like to try two things:
1) Test the LED strips using a DC-DC 600W 10-60V to 12-80V Boost Converter(hopefully without taking the TV apart), but I am not sure how to hook it up. Do I need an external input power source or can I take it from the board somewhere?
2) Replace the IC2004 EPROM as suggested by Olegi. However, on my board this IC is marked 402M40B2Y1(not 24c02 as in Olegi suggest on the LC-40LE810UN's mainboard) and I can't locate this part anywhere, nor can I find evidence this IC is a 24c02 equivalent. Can anyone shed some light on this?

Thank you for helping.

[tom66]

Re: Sharp LC-40LE810UN question

Could have been a shorted panel the whole time.

[tibimakai]

Re: Sharp LC-40LE810UN question

Sorry, but I'm done with this TV. I have found a chipped edge of the LCD. Not sure how bad that is.
It's up for sale, for parts.

[tibimakai]

Re: Sharp LC-40LE810UN question

It's something weird with this TV, sometimes I plug it in and the error code shows up.
But, if I plug it in again, it would be completely dead, no more error code.
If I would wait a while, the error code would show again.
So, I guess you assumption about the STBY voltage may be right.
VDOs, I will check them.
We did a lot of testing on this TV in the past, but I have never got to the bottom of if. This is the hardest TV that I had and it's been almost a year since I have got it. From time to time I will look at it, but I don't know what to do.
Once I have purchased a PS board from partstore.com, but that board did the same thing, nothing changed.
On some of the metal parts of the TV I see corrosion. Specially on the tuner's cover.

[tom66]

Re: Sharp LC-40LE810UN question

2-5 is 5V problem (from memory...), so have you got 5V? Test all SMPS, LDO, on main board.

[tibimakai]

Re: Sharp LC-40LE810UN question

I have two long and five short error code and not one long and two short.

[tibimakai]

Re: Sharp LC-40LE810UN question

Thank you for the idea.
I will have to recheck that TV, because yesterday I had repaired a Westinghouse LED with shorted ribbon cable, close to the LED strip connector and the TV would not show life at all.
I haven't worked much on LED TVs, I'm just gaining a bit of experience with each as I'm working with them.
The issue I have and I can't understand, why all the voltages at the power supply output, sometimes are there and sometimes are all gone(0V).
Twice I have replaced some small IC on the board and I had these voltages back, for a while. Maybe something at the LEDs is shorting out and that is causing these issues?

[Trackstar23]

Re: Sharp LC-40LE810UN question

From my experience working on two Sharp LED TV's (model lc60c6400u) that had the one long flash and two short flashes, both cases involved a poor or disconnected solder joint on the connector attached to the LED light strip. I redid the solder on both connectors just to be safe and both TV's are working great.

I did the Vol down, channel up and power trick to start it, and noticed only the right side of the screen had back lighting. I then confirmed the whole strip was out once I removed all the layers of the screen. I then looked for bad led lights on the strip and all were fine, and also test the voltage at the power supply which tested fine as well. lead me to the connector or wires as the culprit. Of course the wires tested fine, but when I looked at the connector, I noticed the solder at 3 points on the connector had cracked. Removed the old solder and applied some fresh solder and the TV is still working great to this day. Also cleaned the connectors with some contact cleaner (did that first actually to make sure it wasn't just a weak cable connection causing the problem). I just condensed everything I did as much as possible, so feel free to ask questions for clarification if you'd like.

One TV has been in my bedroom for 3 months now and is on almost all day Though not all 2 flash errors will be this, both TV's were bought from two completely different sources. Be forewarned though; wear gloves when removing the various LCD screen layers or you will spend quite some time cleaning internal fingerprints/smudges from the layers (primarily the big thick hard plastic layer)

[tibimakai]

Re: Sharp LC-40LE810UN question

When it had some life in it, I didn't have to push any buttons.
When plugged in, the V turned on for a couple of seconds and then it was keep blinking the error code.
Nothing showed on the screen.
I don't remember the IC number, but that little IC when changed, the voltages come back, but why after a while goes bad, I don't understand.

[jimmyboy111]

Re: Sharp LC-40LE810UN question

The volume down - channel up - power button worked on mine for a moment - the backlights flashed on for just a moment then it powered down and went black
anything for you?

perhaps it actually is one of the backlights

[tibimakai]

Re: Sharp LC-40LE810UN question

Actually, yesterday I took it out, but it didn't have secondary voltages again, the V logo LED did not turn on again. It's a mystery this TV.
I almost purchased both boards for it, but it's way to expensive.
I will wait until I will find some cheaper boards, or a TV with broken screen.
Actually is one right now on Ebay, but the power supply has a bit different part number. DPC-126P 1 A. Mine is only ...126P A.
I don't want to put to much money in it right now, I have different plans with the money I have.

[jimmyboy111]

Re: Sharp LC-40LE810UN question

Whatever happened? did you give up on it .. I have a Sharp LC-60LE810UN with similar symptoms .. different error though 1 slow 1 fast .. lamp failure .. ~165v on the power capacitors

I also tried disconnecting both LED driver plugs on the top right of the board to see if the error changes .. same thing - the only thing that changes is disconnecting the processor board and finally no lights - something tells me the firmware on these kill the TV

[tibimakai]

Re: Sharp LC-40LE810UN question

Bud, it wouldn't be possible to make a LED tester? An LED and a resistor to replace the strips inside the panel?
Just to exclude the LEDs to be the problem.
The voltage there, should be around 90V, no?
If I could check the LEDs and they would check out good, I would buy the mainboard.

Another thing that I have noticed, that how come only the mainboard is rusted and not the PS? Maybe it was already replaced by somebody else trying to repair it?

[tibimakai]

Re: Sharp LC-40LE810UN question

I have inspected the panel and I couldn't see any cracks.
I have also tried measuring the LEDs. While some were lighting up, some others I couldn't get to them to measure. They were way to small for my meter's probe to get a reading. They are to many too.
I'm thinking of getting a mainboard. Found one at partstore for a bit over $77.

[randtek]

Re: Sharp LC-40LE810UN question

Inspect the panel closely with a flashlight. 2-5 Error on these is often caused by a broken LCD panel. The panel 12 V goes from the power board to the main, where it is sent to the TCon, then loops back to the main where it is detected. If the voltage is lost anywhere in this path it will give the 2-5 error.

The fact that you don't have to press the power button for the error to start is meaningless. Most decent TVs remember their power state when they lose power, and will try to return to that state when plugged in. Also, many TVs power up the supply momentarily at plug in as a self-test. In normal operation, it will be short, usually less than 1 second. Either of these situations will cause the error to be displayed, without having pressed the power button.

[tibimakai]

Re: Sharp LC-40LE810UN question

Any more input would be appreciated.
I can turn off the TV from the touch button. I guess that eliminates the main board, no?
It seems that the "high voltage" is not turning on to supply the LEDs.

[tibimakai]

Re: Sharp LC-40LE810UN question

Can I try to apply external 12V to that pin?

[tibimakai]

Re: Sharp LC-40LE810UN question

I have just measured that component and I'm getting 13.5V, 12V, 0V, 2.7V.
The 12V comes on late and cuts off fast as the error pops up.
I'm not measuring less then 12V.

[tibimakai]

Re: Sharp LC-40LE810UN question

I'm not home with the board in front of me, but looking at my first picture it seems that it's at the bottom left corner under that black heat sink.