Sharp LC-42D64U Error Standby

[Topher265]

I'm trying to save a "free" 42" HDTV. Though I've got about $150 in spare boards as I broke my own rule in diagnosis...so it's not so free anymore . I've got a strong automotive background and I'm comfortable diagnosing electrical systems on cars/trucks, so I thought I'd come here to try and fix this TV. I have a Fluke87 DVOM I'm comfortable using.

I've done some searching/reading, and I've recorded some measurements. Pictures are below of the top and bottom of my Main board and the tops of the Power and AC boards. I'll also attach the service manual.

When I attempt to turn it on, the TV will click a couple of times (sounds like a relay click) with a steady power light, then after the 2nd click the power light flashes with the OPC then the Power light flashes again. The screen never lights up and at no point can I see any image on the screen with a light in a dark room. The service manual for the TV (with what I believe the matching code is) states:

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

I've tested the PD connector from the Power Unit to the Main, and here are the results while the TV is attempting to turn on (top to bottom, matching the picture of it below):
LNB: not used
LNB Pow: not used
LNB Cont: not used
PS_ON: 3.67v
AC_DET: 3.984v
PNL_POW: 0.001v
SGND: 0v / 0.3ohm
BU5V: 4.99v
SGND: 0v / 0.3ohm
SGND: 0v / 0.3ohm
UR15V: 14.69v
UR15V: 14.69v

Please advise on what you'd like me to test, or if you want any other pictures. Thanks in advance!

[Topher265]

Re: Sharp LC-42D64U Error Standby

Adding the rest of the photos but the SM won't upload as it's 19.14MB and the limit here is 19.07MB. Advice to trim it down? This is the link on ElektroTanya for the manual.

I should also add that I don't see any obvious capacitor failures or damage marks on either side of any of these boards. I've also tried a couple of the resets using the buttons on the side of the TV but the most I can get is a steady power light. The screen doesn't flicker or light up at any point.

[Topher265]

Re: Sharp LC-42D64U Error Standby

I'm hoping someone here will point me in the right direction :-)

[Topher265]

Re: Sharp LC-42D64U Error Standby

Anyone? I certainly don't want to be a bother. Just need some direction before my wife forces my hand and I have to cut my losses and toss out the set.

[budm]

Re: Sharp LC-42D64U Error Standby

PNL_POW: 0.001v = BAD
Can we see the whole back side of the TV showing all the boards so I can see how all the boards are connected together?
Also need straight shot pictures of the whole board.
DELTA DPS-304BP-1A
Sharp RDENCA235WJQZ Power Supply

[Topher265]

Re: Sharp LC-42D64U Error Standby

I hope these suffice. I now realize most of the lighting in my house really sucks for these types of photos :-)

[budm]

Re: Sharp LC-42D64U Error Standby

https://www.badcaps.net/forum/attach...6&d=1474674369
Something is missing here, I do not see any inverter boards in the pictures.
Also the service manual that I have does not show any ERROR codes listing, adn does match you chassis either.
Can you tell me where you get the service manual from?

[Topher265]

Re: Sharp LC-42D64U Error Standby

Sorry...I managed to cut off the inverters to the right. I attached new pics.

The manual I found was on ElektroTanya:

6-20 should show the LED flash codes

[budm]

Re: Sharp LC-42D64U Error Standby

By the way can you tell us the exact blinking counts from the Power LED and OPC LEDs?
Since you do not have PNL_PWR command signal from the main board to turn on the switched 12VDC to feed the T-CON board, I would expect to the the PNL_12V fail error not the DET_D3V3 codes.

[Topher265]

Re: Sharp LC-42D64U Error Standby

Power and OPC light blink together once then a solo power blink. Then it repeats.

[budm]

Re: Sharp LC-42D64U Error Standby

Power and OPC light blink together once then a solo power blink. Then it repeats.

So power LED blinks twice and OPC blinks once, that will be 'PS_ON
DET_10V failure' per chart.
See post 9.

[budm]

Re: Sharp LC-42D64U Error Standby

Right now it looks like the problem is in the main board because the power supply is putting out the correct STBY5V and the Unregulated 15V, those Voltages are then converted to
A9V, A5V, D5V, D3.3V, D2.5V, D1.8V, VL1.8V, D1.67V, D1.0V, etc (see pdf page 71).
This is not going to be easy due to so many step down Voltage regulators involved.
You will need to check out those Voltages on the main board.

[Topher265]

Re: Sharp LC-42D64U Error Standby

I don't understand what and where to test.

[budm]

Re: Sharp LC-42D64U Error Standby

Can you read schematic and be able to locate the component on the board based on what is shown in the schematic?
This is not and easy thing to work on, and it deals with lots of SMD component so I am not sure how far you are willing and committed to spend lots of times on the board.

[Topher265]

Re: Sharp LC-42D64U Error Standby

Yeah, I can read schematics. I was just a little frustrated earlier. I'm not that committed to spending the time on the TV though. I might look for another Main board. Oh well, I appreciate your time and help.