Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting TVs and Video Sources
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 04-30-2021, 12:57 PM   #1
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Sharp LC-40LE810UN Zero Power

After reading the existing threads on here, I'm still not sure where the problem is exactly. There is no backlight and no standby light when it is plugged in. I don't have much experience working with electronics on this level.

Based on the previous threads (1 , 2) , I've measured these items on the board:



Attached Files
File Type: pdf Delta DPS-126CP-1 A_RUNTKA685WJQZ schematic.pdf (3.47 MB, 14 views)
File Type: pdf LC40-60LE810UN.pdf (8.70 MB, 14 views)

Last edited by xoicorez; 04-30-2021 at 01:35 PM..
xoicorez is offline   Reply With Quote
Old 04-30-2021, 02:29 PM   #2
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,204
Default Re: Sharp LC-40LE810UN Zero Power

So right now with just power supply board connected to AC. Do you get any DCV on the power supply connector pins that goes to the main board?
The connector has name for each pin so make sure to put down the pin name and follow by the Voltage reading for each pin.
__________________
Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/

TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
budm is offline   Reply With Quote
Old 04-30-2021, 02:42 PM   #3
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

I'm not sure which connector that is? Is it PD?
xoicorez is offline   Reply With Quote
Old 04-30-2021, 02:51 PM   #4
nomoresonys
Badcaps Veteran
 
Join Date: Jan 2013
City & State: midwest
My Country: U.S.
I'm a: Knowledge Seeker
Posts: 6,545
Default Re: Sharp LC-40LE810UN Zero Power

Yes PD.
__________________
Signature: Any Stooge can find an "Idiot" by looking in his mirror.
nomoresonys is offline   Reply With Quote
Old 04-30-2021, 03:20 PM   #5
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

Pin 1 - 1 going down to 0
Pin 2 to 10 - 0
Pin 11 - 4.9
Pin 12 0.1

Last edited by xoicorez; 04-30-2021 at 03:26 PM..
xoicorez is offline   Reply With Quote
Old 05-01-2021, 03:43 AM   #6
dick_barton
Badcaps Veteran
 
dick_barton's Avatar
 
Join Date: Aug 2015
City & State: Cardiff
My Country: Wales
Line Voltage: 230V AC, 50Hz
I'm a: Hobbyist Tech
Posts: 6,403
Default Re: Sharp LC-40LE810UN Zero Power

Are you certain that measurement D was 19 ohms and not 19 Kohms?
__________________
Willing to help but I'm no expert.
dick_barton is offline   Reply With Quote
Old 05-01-2021, 01:35 PM   #7
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,204
Default Re: Sharp LC-40LE810UN Zero Power

Quote:
Originally Posted by xoicorez View Post
Pin 1 - 1 going down to 0
Pin 2 to 10 - 0
Pin 11 - 4.9
Pin 12 0.1
To get 16V (C) for the running Voltage for the SMPS circuit, it means that standby power supply is running, that is why you do have standby 5V on pin 11, no need to check anything in that hot side of that power supply section.

As I indicate, PD connector has pin name so you need to put down pin name follow by the Voltage reading so we can easily see what it has does not have for each pin. Also PD connector has 24 pins, so you need to report them all, the exposed pins you can see from the top side of the board are ODD number pins.
budm is offline   Reply With Quote
Old 05-01-2021, 01:54 PM   #8
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

Quote:
Originally Posted by budm View Post
To get 16V (C) for the running Voltage for the SMPS circuit, it means that standby power supply is running, that is why you do have standby 5V on pin 11, no need to check anything in that hot side of that power supply section.

As I indicate, PD connector has pin name so you need to put down pin name follow by the Voltage reading so we can easily see what it has does not have for each pin. Also PD connector has 24 pins, so you need to report them all, the exposed pins you can see from the top side of the board are ODD number pins.

There is only 12 pins on PD?


Last edited by xoicorez; 05-01-2021 at 01:59 PM..
xoicorez is offline   Reply With Quote
Old 05-01-2021, 02:04 PM   #9
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,204
Default Re: Sharp LC-40LE810UN Zero Power

OK, I just look at the label of the connector below where they print the pin names of the PD connector, I see now that connector is LB, not PD, sorry about that, I have a hard time seeing the pictures clearly.
So at this point since you do have standby Voltage to run the main board, so you need to put connectors back in place and check the PD pin Voltages again then hit the power switch to see if any of PD pins (UR13V, AC_DET, PS-ON, PNL_POW) Voltages change state or not.
budm is offline   Reply With Quote
Old 05-01-2021, 02:06 PM   #10
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

.

Last edited by xoicorez; 05-01-2021 at 02:12 PM..
xoicorez is offline   Reply With Quote
Old 05-01-2021, 02:12 PM   #11
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

Quote:
Originally Posted by budm View Post
OK, I just look at the label of the connector below where they print the pin names of the PD connector, I see now that connector is LB, not PD, sorry about that, I have a hard time seeing the pictures clearly.
So at this point since you do have standby Voltage to run the main board, so you need to put connectors back in place and check the PD pin Voltages again then hit the power switch to see if any of PD pins (UR13V, AC_DET, PS-ON, PNL_POW) Voltages change state or not.
The voltages do not change.
xoicorez is offline   Reply With Quote
Old 05-01-2021, 02:15 PM   #12
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,204
Default Re: Sharp LC-40LE810UN Zero Power

So UR13V, AC_DET, PS-ON, PNL_POW all show 0V?

If AC_DET is 0V then that will lock out the other control Voltages, AC_DET should be about 3V for normal operation.

Last edited by budm; 05-01-2021 at 02:18 PM..
budm is offline   Reply With Quote
Old 05-01-2021, 02:21 PM   #13
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

Quote:
Originally Posted by budm View Post
So UR13V, AC_DET, PS-ON, PNL_POW all show 0V?

If AC_DET is 0V then that will lock out the other control Voltages, AC_DET should be about 3V for normal operation.
Sorry, the measurements were incorrect since I didn't connect PD.

UR13V - 12.5 to 0

AC_DET - 0

PS-ON - 2 to 0

PNL-POW - 0.09 to 0.12

Last edited by xoicorez; 05-01-2021 at 02:22 PM..
xoicorez is offline   Reply With Quote
Old 05-01-2021, 02:42 PM   #14
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

I am now reading the old thread and understanding it more. I think I need to replace the optocouplers, PC7703?

Would this work?

They are PC817C but the optocouplers on my board are Cosmo PC817H. They have different CTR based on this PDF?

xoicorez is offline   Reply With Quote
Old 05-01-2021, 02:47 PM   #15
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,204
Default Re: Sharp LC-40LE810UN Zero Power

Quote:
Originally Posted by xoicorez View Post
Sorry, the measurements were incorrect since I didn't connect PD.

UR13V - 12.5 to 0

AC_DET - 0

PS-ON - 2 to 0

PNL-POW - 0.09 to 0.12
I do not understand the reading of XX to YY.
Are you saying when TV is off but plugged into the AC outlet is, I.E. UR13V is 0V when TV is OFF, when TV is on it goes to 12.5V?
Are you also 1005 sure that AC_DET is always at 0V?
budm is offline   Reply With Quote
Old 05-01-2021, 02:57 PM   #16
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

Quote:
Originally Posted by budm View Post
I do not understand the reading of XX to YY.
Are you saying when TV is off but plugged into the AC outlet is, I.E. UR13V is 0V when TV is OFF, when TV is on it goes to 12.5V?
Are you also 1005 sure that AC_DET is always at 0V?
Yes, that is correct. When I press the power button when it is plugged into the AC outlet, UR13V jumps to 12.5 but drops to 0. PNL-POW maintains 0.12 then drops to 0.09 when power button is pressed, but goes back to 0.12.

I measured AC_DET again and it is always at 0.
xoicorez is offline   Reply With Quote
Old 05-01-2021, 08:05 PM   #17
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,204
Default Re: Sharp LC-40LE810UN Zero Power

Quote:
Originally Posted by xoicorez View Post
I am now reading the old thread and understanding it more. I think I need to replace the optocouplers, PC7703?

Would this work?

They are PC817C but the optocouplers on my board are Cosmo PC817H. They have different CTR based on this PDF?

Is there CTR marking on the OPTO on your board?
budm is offline   Reply With Quote
Old 05-01-2021, 08:07 PM   #18
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,204
Default Re: Sharp LC-40LE810UN Zero Power

And what DCV do you get when measure between pin 3 and 4 of the OPTO?
budm is offline   Reply With Quote
Old 05-01-2021, 08:32 PM   #19
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

Quote:
Originally Posted by budm View Post
Is there CTR marking on the OPTO on your board?
The CTR marking on the opto is H, I believe. It's the bottom letter.

Do you suspect the opto is the issue with those readings on PD?
xoicorez is offline   Reply With Quote
Old 05-01-2021, 08:46 PM   #20
xoicorez
New Member
 
Join Date: Apr 2021
City & State: Toronto
My Country: Canada
I'm a: Knowledge Seeker
Posts: 18
Default Re: Sharp LC-40LE810UN Zero Power

The CTR marking on my board isn't on the PDF for some reason.



xoicorez is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2021
Powered by vBulletin ®
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 03:15 AM.
Did you find this forum helpful?