haier 65uf2505 help with T-con problem diagnosis

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

OP needs to learn how to use test equipment properly first.
I do not know how far OP wants to go with this.
I wish I have the board in front of me so I can find out what actually failed just for my own knowledge. Right now I can only guide him since I do not have the board in front of me
I have been doing electronics for 45 years and still learning everyday too.

[yokoono]

Re: haier 65uf2505 help with T-con problem diagnosis

Yes, but it had to start with Ohm's law, the use of the meter, repairing pick-up, radio, an amplifier etc. When you measure a resistance with the TV plugged in, something is wrong. In addition, for such repairs you must have other equipment: hot air station, flux, microscope etc.
Sorry if I upset someone. I've been doing electronics for almost 60 years and I still don't know them all.

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

From reading his post #1, he said he wants to learn.

[yokoono]

Re: haier 65uf2505 help with T-con problem diagnosis

For what knowledge of electronics does this user have, I recommend replacing the t-cone and not repairing it.
After some wrong maneuvers, something else can fail. In addition, a t-con module is cheap.

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

VONE voltage is missing (in most cases it is over 15V). If the voltage is missing when both ribbons are disconnected the defect is in the T-con. Because I don't think you can fix it, I advise you to buy another one.

I suspect the T-CON too since those Boosted Voltage for VONE, AVDD's are generated by the RT6931.
I wonder if that section is getting the 12V for it to run, hopefully OP will do the resistance testing between test points I made him to test in post #22.

[yokoono]

Re: haier 65uf2505 help with T-con problem diagnosis

VONE voltage is missing (in most cases it is over 15V). If the voltage is missing when both ribbons are disconnected the defect is in the T-con. Because I don't think you can fix it, I advise you to buy another one.

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

OP.
BTW, this is the Samsung T-CON board (not exact for your TV) that you can use to understand the typical topology used in the TC-ON board.
As you can see, the AVDD power supply and the VONE power supply are boost converter circuits that step up 12VDC to higher Voltage, so if the RTxxx detects shorted load, the circuit will shutdown, if it is not switching then you will only see 12V at the output of boost converters, that is why I have you test those test points (but someone think it is crazy fools to suggest that) with Ohm meter to find out if there too much loads on those outputs or not or if the circuit in that LCD Bias section is getting the 12V to run or not, those outputs goes to the LCD panel which also have caps and IC's which they can go bad.

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

woow.. whom asked you to do such crazy fool test.. EINSTEIN suggest you??
forget please my last suggestion post.. good luck

Yep as useless as locating 3 Ohms reading on the T-CON Board, it has shorted loads somewhere.
https://www.badcaps.net/forum/attach...2&d=1597284325

https://www.badcaps.net/forum/showth...t=87313&page=3

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

Well, that's embarassing.
Anyway, here's the part number :
RT6931
GQW
3KT1E

See picture for reference.

Thanks for IC P/N.
BTW, I also need the Voltage of those test points in your post # 8 without BOTH ribbons cables connected to the LCD panel.
Also do not use Ohm mode to test resistance when the TV is plugged in and have power apply, always test resistance without power to the board or you can damage your meter.
Please also look at my post #22.

[Dontlikeusernames]

Re: haier 65uf2505 help with T-con problem diagnosis

I am looking for abnormal low Ohms reading on those test points.
P/N = Part number as printed on top of the IC.

Well, that's embarassing.
Anyway, here's the part number :
RT6931
GQW
3KT1E

See picture for reference.

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

1) Nothing connected to the T-CON board.

2) Check the resistance between point 'A' that I marked and point 'B', 'C', and 'D' using 200 Ohm scale. Basically you will be testing resistances between A and B, A and C, A and D.

3) Check the resistance between Point 'B' and 'C' using 200 Ohm scale.

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

OP, can I see good clear pictures of the whole bottom side of the T-CON?

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

insulate your probes so tip only showing

He was testing the resistance with TV on.

[petehall347]

Re: haier 65uf2505 help with T-con problem diagnosis

insulate your probes so tip only showing

[budm]

Re: haier 65uf2505 help with T-con problem diagnosis

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.

[budm]

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.

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

[Diah]

Re: haier 65uf2505 help with T-con problem diagnosis

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

[budm]

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.

I am looking for abnormal low Ohms reading on those test points.
P/N = Part number as printed on top of the IC.

[Dontlikeusernames]

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.

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.

[budm]

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 :/ .

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.