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Old 08-12-2020, 06:37 PM   #1
Dontlikeusernames
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Default haier 65uf2505 help with T-con problem diagnosis

Hi!
A bit of a disclaimer right off the bat : I don't have much experience in electronic repair, but I'm more than willing to learn and spend time researching what has to be researched. However, I expect I'll have to ask for guidance on some of the advice you'll make me, as I might not exactly what you're asking for. As for equipment, I have a basic soldering iron, a multimeter and a very good electronic store nearby.

My problem : I was given a broken TV, model Haier 65uf2505. From my initial analysis, I believe the t-con is defective. Here's what I noticed :
- The TV turns on
- Screen turns to a glowing gray
- The backlight definitely works
- I have sound coming through the TV

Now, what I would like to do is try to repair the actual part that is defective (be it on the t-con or someplace else) rather than replace the whole board as I want to learn as much as possible and spend as little as possible. I don't need this tv to work, I would just like to give it a second life and prevent another usable electronic hiting the landfill.

I'm removed the t-con board from the tv (pictures below) and upon close visual inspection (I don't have a microscope, I use an high res picture and I zoomed in), I don't see anything highly suspicious. However, my eye is not well trained. Same can be said for the power board and the other board (I forgot the name).

My question is thus : where should I start? I recon from reading Budm basic troubleshooting guide that I should check if the t-con is getting proper power, is that correct? If so, I would need help to know what to measure exactly.

Pictures :
t-con board (removed from TV)


back of tv (t-con board missing because removed)






Thank you for your time and help.
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Old 08-12-2020, 07:56 PM   #2
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Default Re: haier 65uf2505 help with T-con problem diagnosis

1) Check the resistance of the Fuse F1 (small white body with 7A printed on top), it should show the same resistance when you touch your two meter probes together, if it does, the put all the board back in place with all the mounting screws and cables all connected backup.
2) Plug the TV in and turn it on then check the DC Voltage between each end of the fuse against chassis GND, it should be 12VDC.
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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
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Old 08-12-2020, 08:47 PM   #3
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Hey! Thanks for getting back to me so quickly.
I tested the resistance and it gives me the same reading as when I touch both prongs together.
I can’t quite test the dc voltage now, I’ll get to it tomorrow, but just to be clear (English isn’t my mother tongue), chassis GND refers to chassis ground right? And that chassis ground would be which part of the board? Would the metallic part (bronze color) near the screw holes be a good spot? I’m guessing it’s not all that different then when I’m boosting a car in the sense that the black prong of my meter goes on the chassis GRN and the red prong goes on each side of the fuse.


Quote:
Originally Posted by budm View Post
1) Check the resistance of the Fuse F1 (small white body with 7A printed on top), it should show the same resistance when you touch your two meter probes together, if it does, the put all the board back in place with all the mounting screws and cables all connected backup.
2) Plug the TV in and turn it on then check the DC Voltage between each end of the fuse against chassis GND, it should be 12VDC.

Last edited by Dontlikeusernames; 08-12-2020 at 08:55 PM..
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Old 08-12-2020, 09:23 PM   #4
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Quote:
Originally Posted by Dontlikeusernames View Post
Hey! Thanks for getting back to me so quickly.
I tested the resistance and it gives me the same reading as when I touch both prongs together.
I can’t quite test the dc voltage now, I’ll get to it tomorrow, but just to be clear (English isn’t my mother tongue), chassis GND refers to chassis ground right? And that chassis ground would be which part of the board? Would the metallic part (bronze color) near the screw holes be a good spot? I’m guessing it’s not all that different then when I’m boosting a car in the sense that the black prong of my meter goes on the chassis GRN and the red prong goes on each side of the fuse.
Chassis is connected to the cold side circuit ground when boards are mounted to the chassis with the screws so the chassis become cold side circuit ground that you can use for ground ref. when making Voltage reading in the cold side, that is why it is important that all the board mounting screws are in place and properly tightened so all the boards will be properly grounded together.
So black probe on the metal chassis, Red to the end of the fuse, just like you said.
English is also my second language, so my comprehension and the way I word things may not look right.

Last edited by budm; 08-12-2020 at 09:25 PM..
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Old 08-13-2020, 09:54 AM   #5
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Some update :

I screwed the t-con board back in place, plugged all the cables and turned on the tv.
I checked the DC voltage of the Fuse F1 and it gives me the expected 12V on both sides.
What should I test next?

Quote:
Originally Posted by budm View Post
1) Check the resistance of the Fuse F1 (small white body with 7A printed on top), it should show the same resistance when you touch your two meter probes together, if it does, the put all the board back in place with all the mounting screws and cables all connected backup.
2) Plug the TV in and turn it on then check the DC Voltage between each end of the fuse against chassis GND, it should be 12VDC.
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Old 08-13-2020, 10:08 AM   #6
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Default Re: haier 65uf2505 help with T-con problem diagnosis

try this test and report back the result.
1-the tv most have signal and you can hear the sound of the signal
2 - remove one ribbon cable once at time ( ribbon cable you have 2 between the t-con and the panel ) and see if you half screen displayed ( do it for both left and right )
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Old 08-13-2020, 10:18 AM   #7
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Default Re: haier 65uf2505 help with T-con problem diagnosis

2 - remove one ribbon cable once at time ( ribbon cable you have 2 between the t-con and the panel ) and see if you half screen displayed ( do it for both left and right )
3 - Measure the voltages at the points marked in red and see if there are any differences when connecting the ribbons. Especially the VONE voltage.
Attached Images
File Type: jpg RjgJzkk.jpg (750.7 KB, 10 views)
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Old 08-13-2020, 12:39 PM   #8
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Ok! After much effort, I did what you asked for :
I turned on the tv and check DC voltage on the marked spot. I tried to double and triple check all results, but don't hesitate to ask me to measure another time some spots if something doesn't make sense.
The results are written on the attached image itself (might need to zoom in a little to see) in red, in the following format :
x / x / x -->*both ribbons / left ribbons / right ribbons

Thank you for your help!


Quote:
Originally Posted by yokoono View Post
2 - remove one ribbon cable once at time ( ribbon cable you have 2 between the t-con and the panel ) and see if you half screen displayed ( do it for both left and right )
3 - Measure the voltages at the points marked in red and see if there are any differences when connecting the ribbons. Especially the VONE voltage.
Attached Images
File Type: jpg RjgJzkk.jpg (756.4 KB, 15 views)
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Old 08-13-2020, 12:39 PM   #9
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Thank you for your help! I tried and got no partial image.

Quote:
Originally Posted by Diah View Post
try this test and report back the result.
1-the tv most have signal and you can hear the sound of the signal
2 - remove one ribbon cable once at time ( ribbon cable you have 2 between the t-con and the panel ) and see if you half screen displayed ( do it for both left and right )
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Old 08-13-2020, 01:13 PM   #10
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Quote:
Originally Posted by Dontlikeusernames View Post
Ok! After much effort, I did what you asked for :
I turned on the tv and check DC voltage on the marked spot. I tried to double and triple check all results, but don't hesitate to ask me to measure another time some spots if something doesn't make sense.
The results are written on the attached image itself (might need to zoom in a little to see) in red, in the following format :
x / x / x -->*both ribbons / left ribbons / right ribbons

Thank you for your help!
Check the resistance of those test points in the LEFT side of the board where IC01 is with ref to GND, same on VONE test points.
What is the P/N of that IC01 in that section?

Last edited by budm; 08-13-2020 at 01:16 PM..
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Old 08-13-2020, 01:51 PM   #11
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Ok, here's what I understand from what you're asking me :

I think you want me to check the resistance to ground of the test points that are on the left side of the boards (the side where most of the DC results were 0), meaning I will place my multimeter on resistance mode, place the black prong on the chassis and the red on the different spots.
However, where exactly should I place the red prong? I'm currently trying to place it on the super small metal spot near the circles I was given, but should I also place it on the different parts beside, like the different resistors/transistors/diodes nearby? For instance, to the right of VONE there is a small metal dot and then three resistors, should I just touch the metal spot, or am I to measure the resistance to GND of the three resistors?

I can't find IC01 :/ .


Quote:
Originally Posted by budm View Post
Check the resistance of those test points in the LEFT side of the board where IC01 is with ref to GND, same on VONE test points.
What is the P/N of that IC01 in that section?
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Old 08-13-2020, 02:02 PM   #12
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Default Re: haier 65uf2505 help with T-con problem diagnosis

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Originally Posted by Dontlikeusernames View Post
Thank you for your help! I tried and got no partial image.
as this test nothing show on the screen and other test of VCC you have on T-CON, i would suggest you to make visual inspection to the screen before you go forward to spend money..

just take out the rand cover of the panel to have access visually to inspect the screen glass at the end ..specially the 2 corner left and right if there are any damage to the thin film which found downside the glass.
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Old 08-13-2020, 02:14 PM   #13
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Quote:
Originally Posted by Dontlikeusernames View Post
Ok, here's what I understand from what you're asking me :

I think you want me to check the resistance to ground of the test points that are on the left side of the boards (the side where most of the DC results were 0), meaning I will place my multimeter on resistance mode, place the black prong on the chassis and the red on the different spots.
However, where exactly should I place the red prong?
I'm currently trying to place it on the super small metal spot near the circles I was given, but should I also place it on the different parts beside, like the different resistors/transistors/diodes nearby? For instance, to the right of VONE there is a small metal dot and then three resistors, should I just touch the metal spot, or am I to measure the resistance to GND of the three resistors?

I can't find IC01 :/ .
The same test points that you were testing the Voltages earlier, we are just repeating the same test points but set meter to Ohm mode instead.
I still need the P/N of the IC i request, it is black square IC to the right of RSB1. See picture.
Attached Images
File Type: jpg LCD bias IC.jpg (2.17 MB, 12 views)

Last edited by budm; 08-13-2020 at 02:27 PM..
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Old 08-13-2020, 03:21 PM   #14
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Default Re: haier 65uf2505 help with T-con problem diagnosis

I didn't have much success trying to get the resistance of the check points on the left side of the board. Every spot I tried to check didn't make the meter react, or if so, value would bounce around and go back to default ("1"). I tried cheching the resistance of some resistors by placing both probes on each end and it was showing "normal" values. So I'm not sure why I'm not getting anything on the other spots.
Tv was turned on, meter was set to Ohm, black probe on the chassis and red probe going around the different marked spots on the picture.
See the attached picture to see what my meter gives me as a result for each of the spots.

As for the P/N (which I assume stands for positive/negative) of the IC you requested, I don't know how to measure that, can you give me some pointers?Thank you for the picture, I located the proper part.



Quote:
Originally Posted by budm View Post
The same test points that you were testing the Voltages earlier, we are just repeating the same test points but set meter to Ohm mode instead.
I still need the P/N of the IC i request, it is black square IC to the right of RSB1. See picture.
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Old 08-13-2020, 03:27 PM   #15
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Quote:
Originally Posted by Dontlikeusernames View Post
I didn't have much success trying to get the resistance of the check points on the left side of the board. Every spot I tried to check didn't make the meter react, or if so, value would bounce around and go back to default ("1"). I tried cheching the resistance of some resistors by placing both probes on each end and it was showing "normal" values. So I'm not sure why I'm not getting anything on the other spots.
Tv was turned on, meter was set to Ohm, black probe on the chassis and red probe going around the different marked spots on the picture.
See the attached picture to see what my meter gives me as a result for each of the spots.

As for the P/N (which I assume stands for positive/negative) of the IC you requested, I don't know how to measure that, can you give me some pointers?Thank you for the picture, I located the proper part.

I am looking for abnormal low Ohms reading on those test points.
P/N = Part number as printed on top of the IC.
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Old 08-13-2020, 03:36 PM   #16
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Default Re: haier 65uf2505 help with T-con problem diagnosis

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Originally Posted by Dontlikeusernames View Post
Tv was turned on, meter was set to Ohm, black probe on the chassis and red probe going around the different marked spots on the picture.
See the attached picture to see what my meter gives me as a result for each of
woow.. whom asked you to do such crazy fool test.. EINSTEIN suggest you??
forget please my last suggestion post.. good luck
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Old 08-13-2020, 03:59 PM   #17
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Default Re: haier 65uf2505 help with T-con problem diagnosis

Quote:
Originally Posted by Dontlikeusernames View Post
I didn't have much success trying to get the resistance of the check points on the left side of the board. Every spot I tried to check didn't make the meter react, or if so, value would bounce around and go back to default ("1"). I tried cheching the resistance of some resistors by placing both probes on each end and it was showing "normal" values. So I'm not sure why I'm not getting anything on the other spots.
Tv was turned on, meter was set to Ohm, black probe on the chassis and red probe going around the different marked spots on the picture.
See the attached picture to see what my meter gives me as a result for each of the spots.

As for the P/N (which I assume stands for positive/negative) of the IC you requested, I don't know how to measure that, can you give me some pointers?Thank you for the picture, I located the proper part.

BTW, you do not test the resistance when device are powered.

Last edited by budm; 08-13-2020 at 04:14 PM..
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Old 08-13-2020, 04:06 PM   #18
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Default Re: haier 65uf2505 help with T-con problem diagnosis

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Originally Posted by Diah View Post
woow.. whom asked you to do such crazy fool test.. EINSTEIN suggest you??
forget please my last suggestion post.. good luck
Hey fools, if testing the resistance of the output of each power supplies for low resistance or shorts is crazy fool test, then you have no idea what you are talking about or how to go about troubleshooting.
Stop making fools of yourself.
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Old 08-13-2020, 04:19 PM   #19
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Default Re: haier 65uf2505 help with T-con problem diagnosis

insulate your probes so tip only showing
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Old 08-13-2020, 04:38 PM   #20
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insulate your probes so tip only showing
He was testing the resistance with TV on.
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