IQ SMART TV 22" weird problem

[rippergr]

Hello all,
I have a very strange problem with a TV. It works fine for several days and one day without any notification it just doesnt turn on. It shows a red light which is standby light and it doesnt turn on. I hear a strang wisssssss sound from the board.
If I unplug it from power and leave it several hours some times it works again and some times it shutdown even the red standby light.
I am attaching an image of the board

[jazzie366]

Re: IQ SMART TV 22" weird problem

Hello all,
I have a very strange problem with a TV. It works fine for several days and one day without any notification it just doesnt turn on. It shows a red light which is standby light and it doesnt turn on. I hear a strang wisssssss sound from the board.
If I unplug it from power and leave it several hours some times it works again and some times it shutdown even the red standby light.
I am attaching an image of the board

Well, I see a CapXon GF series in the top. That's a series known for failing when being run hard. If it's being run within spec it should be fine, however I'd consider it suspect due to the fact I've seen it fail in Dell PSUs.

Also, check caps on other boards as well, doesn't always have to be the power board that's the problem.

Could you upload pics of the other boards as well please?

Also, the cap above the two brown ones on the right side of the picture, what brand is that? The printing on it looks extremely low quality, could be a crap cap.

One more thing, please upload some pictures of under the heatsinks on the board, would love to see what's under. Could be a cap hidden under one of those that's bulged.

Also, be careful of the high voltage caps, that shit is no joke.

[rippergr]

Re: IQ SMART TV 22" weird problem

The other board seems ok, I hear the weird sound from the power board and louder near the power cable which comes from power outlet.
I attach the other side board and the second board. I also attached the capacitor above two browns. I dont know how it is called.
Also in the rear view of the board I marked the components that I have changed so far.

[petehall347]

Re: IQ SMART TV 22" weird problem

Hello all,
I have a very strange problem with a TV. It works fine for several days and one day without any notification it just doesnt turn on. It shows a red light which is standby light and it doesnt turn on. I hear a strang wisssssss sound from the board.
If I unplug it from power and leave it several hours some times it works again and some times it shutdown even the red standby light.
I am attaching an image of the board

the white plug con1 looks wonky to me

[rippergr]

Re: IQ SMART TV 22" weird problem

the white plug con1 looks wonky to me

The back of the TV just pulls down the plug. It's quite sturdy.

[rippergr]

Re: IQ SMART TV 22" weird problem

Can you tell me what is that yellow box component above thermal fuse?
The noise comes from there or from around there

[petehall347]

Re: IQ SMART TV 22" weird problem

safety capacitor by looks of it

[dskall]

Re: IQ SMART TV 22" weird problem

Might pull con1 and see if any arcing in connector or bad solder joints

[rippergr]

Re: IQ SMART TV 22" weird problem

Might pull con1 and see if any arcing in connector or bad solder joints

That was a good idea. I removed the con1 and solder a cable directly on board but still the same noise and cannot power on the TV altough it has the standby led when I push the on button nothing happens or just shut down the led.

[dskall]

Re: IQ SMART TV 22" weird problem

I would carefully inspect board for bad connections. Heat or cool board to see if it will turn on.

[rippergr]

Re: IQ SMART TV 22" weird problem

I would carefully inspect board for bad connections. Heat or cool board to see if it will turn on.

I resolder most of the components . I cool the board and I heat it but it still does the same.
Is there any change that it's problem from the thermal fuse (I changed it because it was burned) or the yellow square capacitor?

[dskall]

Re: IQ SMART TV 22" weird problem

Need good clear straight on pictures of back of tv with cover off and each board.

Need voltages from connector that goes from power supply board to main board. Will need pin#- PIN DESCRIPTION -Pin voltage in standby-Pin voltage when pushing power button and picture of connector on power supply board.
Format:
Pin# - Pin Description - Pin Voltage standby - Pin voltage power on
1 - XXXXXXX - XXv - XXXv
2 - XXXXXXX - XXXv - XXXv
3 - XXXXXXX - XXXv - XXXv
4 - etc.

[rippergr]

Re: IQ SMART TV 22" weird problem

Ok the pins are

Descr. Standby Volt Power On Voltage
1)+12V 12.05 12.05
2)+12V 12.05 12.05
3)on/off 0.03 0.03
4)ADJ 5.03 5.03
5)GND
6)GND

I hope the pictures are clear

[rippergr]

Re: IQ SMART TV 22" weird problem

Anyone has any idea what to look/change?

[dick_barton]

Re: IQ SMART TV 22" weird problem

With the main board disconnected what voltages do you have on pins 1-6 when you switch on?

[rippergr]

Re: IQ SMART TV 22" weird problem

If I unplug the logic board I cannot power on the TV, it has no lights.
The voltages on the pins are on 12V rails 12.05V and in all other 0V

[dskall]

Re: IQ SMART TV 22" weird problem

Your not getting any change on on/off pin? Need to check voltages on main at regulators

[rippergr]

Re: IQ SMART TV 22" weird problem

What do you mean regulators? you mean transistors?

[attainteddragon]

Re: IQ SMART TV 22" weird problem

these are your voltage regulators.
i cant make out what the output voltage should be from the pics.

measure them from left to right. center pin is the same as the tab pin.
list what is written on the top line of each ic.

[rippergr]

Re: IQ SMART TV 22" weird problem

all of them are 1117 B 33 632K
and all of them have 0v on all pins except the top one which has 3.3V on midle pin and 5V on right pin and 0V on left pin