LCC5255U going to error standby

[budm]

Re: LCC5255U going to error standby

Yes, it should be 3.3V as specified in the diagram, if you are at the correct inductor. I hope that the diagram that you gave the link to match your board. Can you take good closed up around that 3.3V IC 9603?

[budm]

Re: LCC5255U going to error standby

You should also check the other buck regulator outputs on that same sch page I redlined to see if they are putting out correct voltages then you know that the sch match your TV.

[jkomorek]

Re: LCC5255U going to error standby

Thanks, I will take a look when I get home this evening. I very much appreciate your assistance.

[jkomorek]

Re: LCC5255U going to error standby

Yes, it should be 3.3V as specified in the diagram, if you are at the correct inductor. I hope that the diagram that you gave the link to match your board. Can you take good closed up around that 3.3V IC 9603?

Here are two photos of 9603, front and back. Sorry, I am still trying to wrap my head around your other requests. I will try to move faster, though I am clearly still learning here.

[budm]

Re: LCC5255U going to error standby

OK, if you look at the PDF in post 12, you will see that the 13V is also used for other switching regulator circuits.
You need to check the DC voltages on both ends of (Black probe of the meter to the chassis)
L9601 which is for 5.2V power supply
L9602 which is for 1.2V power supply
L9604 which is for 2.6V power supply

If the circuits match your TV, then you should see those voltages as listed above, then we know that we are using the correct diagram.

[jkomorek]

Re: LCC5255U going to error standby

Here are the voltages. It would appear to be the correct board:

L9601 = 5.24v / 5.24v
L9602 = 1.217v / 1.243v
L9604 = 2.65v / 2.622v

[budm]

Re: LCC5255U going to error standby

So that means you do have problem with 3.3v power supply IC or components around it. Other power supplies are putting out like they should.

[jkomorek]

Re: LCC5255U going to error standby

Is the "power supply IC" an on IC on the power supply board, or is that actually on the main board?

[budm]

Re: LCC5255U going to error standby

The one on page 12 that we were checking where the other voltages you had just verify. See post 19 and later to what we have been testing.

[jkomorek]

Re: LCC5255U going to error standby

The one on page 12 that we were checking where the other voltages you had just verify. See post 19 and later to what we have been testing.

Sorry, I don't understand that answer, but that's ok.

What I really need to understand now is where the problem is. I am guessing that the power supply is fine and the problem exists with one or more components on the Main Board.

Do you agree?

[budm]

Re: LCC5255U going to error standby

That is correct, you were only getting 1.99v in your post 20 instead of 3.3v as the circuits required..

[jkomorek]

Re: LCC5255U going to error standby

Great! I will pick up another main board from eBay and give it a shot. I made an attempt to work backwards from where we found the low voltage, but I cannot seem to find a good datasheet on the Voltage Regulator IC and I cannot imagine testing the other small components around it.

Thank you very much for your help, Bud. This was a long thread, but looking back on it I think I follow your basic logic. We started by checking the main power going into the main board then asserting that all of the ICs (at least from the first diagram in the service manual) were getting powered correctly. I can only assume that if these looked good that we would have continued walking through the main board.

Again, i appreciate your time. I will follow up once i get a new board installed and tested.

[jkomorek]

Re: LCC5255U going to error standby

I installed the new main board today and it's good as new! I rechecked the output voltage on the voltage regulator we looked at, and it is in fact 3.3v as the schematic indicated.

Thanks again for the help!

[budm]

Re: LCC5255U going to error standby

Great news, now if you want, you can try replacing that IC for the 3.3v and see if that will fix the problem.

[jkomorek]

Re: LCC5255U going to error standby

I would be curious to try and get the old board working, but I am a bit timid to mess with a working TV. Also, I can't even find a place to order the specific IC I need V5893

[ahickman]

Re: LCC5255U going to error standby

Budm, hope you around this evening and doing well. I am working on the identical set and have also found that IC9603 is putting out 2.0VDC. It briefly rises to 3.1VDC when the PS first turns on, but quickly falls to 2.0VDC. Searching for a replacement for LV5893M, but not findings a source. Can you suggest a possible replacement IC?

[budm]

Re: LCC5255U going to error standby

@ahickman, I have no luck finding the replacement either.

[ahickman]

Re: LCC5255U going to error standby

If I provided 3.3 V externally, would I damage anything?

[37PF7320A/37]

Re: LCC5255U going to error standby

I have just fixed the sharp aqueous LCD tv.
My symptoms were immediately turninI on the tv I get a blinking green light. No other error codes. No sound, no picture.*

I tried the reset but it didnot wok.

There were nobulgcapacitors intros. No meltedanything easily detectable.

I measured some of the small transformers on the master inverter board. The resistance was OL which means no resistance at all. This is bad. All ottransfer sortersmeasured 1.31k ohms.

*

I decided to buy this part on eBay for 12 $.

After soldering it on to theinverterboard the tv worked good aS new.

*

Sharp aquos *lcc52u55 fix

Sharp aquos lcc52u55 resolved
--------------------------------------

I have a LC-C5255U which does not power on.

When I first got it home and turned it on, the power light flashed twice and the OPC flashed twice as well. I tracked down the service manual for the TV and it states:

DET_D3V3 (pin 36) failure (L). D3.3V is not applied.
If error is detected during operation, error standby is activated by polling.277bp

I took the Power supply off so that I could examine it for burn marks, etc. After not seeing anything, I put it back on, turned on the TV and now I am getting the power light flashing three times and the OPC flashing once, which according to the service manual means:

Initial communication from the main CPU is not received.
(After canceling the reset, request for the monitor model No.
is not received.)
Communication line failure or main CPU start-up failure.

If I unplug the inter boards I continue to get the same main CPU start-up failure.

I have attached a few photos of the power supply as a starting point, please let me know if any other photos would be helpful.

[37PF7320A/37]

Re: LCC5255U going to error standby

I have just fixed the sharp aqueous LCD tv.
My symptoms were: immediately turning on the tv I get a blinking green light. No other error codes. No sound, no picture.* Cannot shut tv off unless I unplug it.

I tried the reset sequence but it did not work

There were no bulging caps or melted fuses at all. No meltedanything easily detectable.

I measured some of the small transformers on the master inverter board. The resistance was OL which means no resistance at all. This is bad. All of the other transformers measured 1.31k ohms.

*

I decided to buy this replacement part on eBay for 12 $. It was a transformer removed from a other aqueous inverter board exact fit.

After soldering it on to theinverterboard the tv worked good aS new.

*

Sharp aquos *lcc52u55 fix

Sharp aquos lcc52u55 resolved