Hisense TV 40K321UW no led does not turn on

kalesh

Member (✔)
Hello,
Sorry for asking on Christmas weekend.

I am looking at the main board of a Hisense TV. There is no Led Light with power plugged in and it does not turn on.

Theres 16V and 12V output. The 12V does get 12v when power is plugged in. But the 16V des not get power.

There is a pin labeled "sw" which I assume is switch. It seems as if it may be shorted to ground. As
1. There is continuity between ground and SW
2. There is 12V between SW and 12V pin.

So I have two questions:
1. Should the 16V pin get power with power plugged in or does it need to be turned on?
2. If it needs to be turned on What can I do to turn it on? short sw to 12V, gnd or something else maybe?
3. in your opinion does it seem that sw is shorted to ground?
4. If so what are the things I could check.

Thanks for the help
 

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Admin

desktops & Laptops
Support
Hello,
Sorry for asking on Christmas weekend.

I am looking at the main board of a Hisense TV. There is no Led Light with power plugged in and it does not turn on.

Theres 16V and 12V output. The 12V does get 12v when power is plugged in. But the 16V des not get power.

There is a pin labeled "sw" which I assume is switch. It seems as if it may be shorted to ground. As
1. There is continuity between ground and SW
2. There is 12V between SW and 12V pin.

So I have two questions:
1. Should the 16V pin get power with power plugged in or does it need to be turned on?
2. If it needs to be turned on What can I do to turn it on? short sw to 12V, gnd or something else maybe?
3. in your opinion does it seem that sw is shorted to ground?
4. If so what are the things I could check.

Thanks for the help
does STB exist or not !
 

kalesh

Member (✔)
Check if the eeprom on your motherboard PIN8 has 3.3 V OR NOT .
It has 3.3 V, I hope I have identified the eeprom correctly.
It has 3.3v input on one side and 3.3v output on the other.
I have attached the picture marked with the places it has 3.3V
but it does not have 3.3v where it is marked 3.3v on the motherboard.

I guess the issue may be somewhere within this area?
 

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Admin

desktops & Laptops
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It has 3.3 V, I hope I have identified the eeprom correctly.
It has 3.3v input on one side and 3.3v output on the other.
I have attached the picture marked with the places it has 3.3V
but it does not have 3.3v where it is marked 3.3v on the motherboard.

I guess the issue may be somewhere within this area?
This is not an eeprom.
 

Admin

desktops & Laptops
Support
Thank you for bearing with my noob questions
I managed to locate the eeprom.
It does not have 3.3v on pin 8
in fact it does not have any voltage on any of the pins.
Can you check R847= ohm !
 

kalesh

Member (✔)
1. There is continuity between ground and SW
Than it seem there's no short circuit between Ground and SW
Thank you for your help and answers.
So this is the situation now
1. the 12V output outputs 12V when power supply board? is not connected to the motherboard. And outputs 3.3V when it is connected to the motherboard.
2. The 3.3v goes to the motherboard and is seen in a few locations (as marked on the image posted before)
3. It does not get to the point marked 3.3v on the motherboard and it does not get to the eeprom as well.

Any ideas on what to test?

Thanks
 
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