hitachi 75hl16t64u - not responding to remote control

[lotas]

The two IR sensors have the same part number: 17LD186.

Now I understand that you did not change the sensor itself, but the entire board with the sensor, try disconnecting the board with the joystick (buttons) and check without it.

[dfear]

I have taken many voltage readings on both original and replacement main boards and IR sensor boards.

Here are the results:


Voltage results are in pin order (1-5).

Original main board.
====================
Original IR Sensor
------------------
STANDBY
--------------
Gnd
2.96
.223
.026 or .077
11.85

ON
---
Gnd
.0215
11.59
.0765
11.83


Replacement IR Sensor
---------------------
STANDBY
Gnd
2.84
.230
.078
11.85

ON
Gnd
.0215
11.59
.077
11.83

Replacement main board.
=======================
Original IR Sensor
------------------
STANDBY
-------
Gnd
2.97
.233
5.57
11.85

ON
--
Gnd
.0217
11.58
5.575
11.83

Replacement IR Sensor
---------------------
STANDBY
-------
Gnd
2.84
.239
5.56
11.85

ON
--
Gnd
.0214
11.58
5.56
11.84


The only significant difference in voltage in the pin 4 voltage reading. The difference in readings readings between the original main board and the the replacement main board is what the TV is doing. The original main board was only displaying the no input signal message and the replacement main board was displaying the first time setup wizard.

[dfear]

Now I understand that you did not change the sensor itself, but the entire board with the sensor, try disconnecting the board with the joystick (buttons) and check without it.

The joystick button is on the main board.

[nomoresonys]

It's hard to tell exactly what you have done as to the suggestions, so if you have not, do exactly this for my test. take batteries out of remote, hold on/off button on remote down for 1 whole minute let go, then push ALL the other buttons several times give them good pushes not just light, unplug tv from power, hold the power on/joystick whatever button the tv has down for 30 seconds, wait 2 minutes, plug tv back in, put batteries back in remote and try it. If still the same try a universal remote, just see if it will power on the tv, we just want to see if a remote can communicate with the tv.

[EazyBone]

Yea, I think you need a new remote. Good luck 🤞🤞

[nomoresonys]

I can not help if tests are not performed and reported, it just makes it too hard. Remote troubleshooting is pretty much working in the blind, so you need very precise communication and directions followed.

[yokoono]

1. The motherboard was replaced with another one from a different TV model with a different code for the remote control
2. A software was rewritten from another model of TV using another model of remote control
3. Use a programmable TV remote control (memorized codes).

[vinceroger69]

1. The motherboard was replaced with another one from a different TV model with a different code for the remote control
2. A software was rewritten from another model of TV using another model of remote control
3. Use a programmable TV remote control (memorized codes).

I was also thinking this too i wonder if the owner swapped the mainboard out themselves when that did not fix it , they took it to a repair shop now psu sorted now the tv is now having this issue as wrong mainboard

[EazyBone]

I was also thinking this too i wonder if the owner swapped the mainboard out themselves when that did not fix it , they took it to a repair shop now psu sorted now the tv is now having this issue as wrong mainboard

I've had this happen also on a Sony. Got the right board in and it was fixed.

[dfear]

I was also thinking this too i wonder if the owner swapped the mainboard out themselves when that did not fix it , they took it to a repair shop now psu sorted now the tv is now having this issue as wrong mainboard

Check here: https://www.badcaps.net/forum/troubl...52#post3342852

This TV was working until the issue with the power supply board occurred. The main board and the ir sensor board are (to the best of my knowledge) the one from the factory and are "paired" together. The replacement main board and sensor boards are quite possible not.

FYI: I am the repair shop.

[nomoresonys]

Any update?

[dfear]

Any update?

Yes, The IR receiver on both sensor boards have been confirmed faulty with an oscilloscope.

[nomoresonys]

Thanks, that's why I suggested testing those signals.