Haier LCD TV 40D3500M

[jazzman72]

Hello friends,

a friend of mine has this old TV. He told me that once the TV is off, needs time to turn it back on and one day just stopped working. I found the issue in the stby circuit and fixed it. Now I have stable output voltages and I am able to see a red LED lit on of the infrared board. Using a remote I can turn the TV on but once turns off I have to unplug the power cord maybe for 5/10 min to get the TV back on (sometimes this led on is not getting on) While checking the main board I found one of the small resistors close to the processor on the logic board out of the track, but I don't think that causing the issue. Any thoughts on this ? I will submit some photos later this afternoon.

[nomoresonys]

Re: Haier LCD TV 40D3500M

Can you show us a picture of this "resistor out of track"?

[jazzman72]

Re: Haier LCD TV 40D3500M

Can you show us a picture of this "resistor out of track"?

Sorry for the late response. Was out of the city. Let me repeat this again.

If the IR board is energized properly, the LED goes on and almost every time I can turn on the TV from the remote and it works fine. Once the TV turned off from the remote (I disconnected the control button board to simplify the test) I can't turn the TV back on. Sometimes works, sometimes doesn't work but most of the time does not. The resistor#115 (the once across pin 32 or 33 of the processor, not tested) was found out the trace. I removed it then put it back but nothing happened. I ordered a new microprocessor, since testing the logic board is above my knowledge. Also replaced a few caps but no luck. Original caps were found good.

[lotas]

Re: Haier LCD TV 40D3500M

Wait until you change the processor, if there is a programmer, then read the data, the firmware (dump) of this spi flash and write this dump into a new chip.

[jazzman72]

Re: Haier LCD TV 40D3500M

Wait until you change the processor, if there is a programmer, then read the data, the firmware (dump) of this spi flash and write this dump into a new chip.

it will be challenging

One thing I would like to add. When IR board takes a proper voltage, I have got 3.3v measured across the micro chip pins if not, 3.3v is not present on some pins.

[diif]

Re: Haier LCD TV 40D3500M

There looks to be some damage to the PCB above the spi flash.

[jazzman72]

Re: Haier LCD TV 40D3500M

yep. i see it now. the one near to the cap#154 and heat sink leg.

[jazzman72]

Re: Haier LCD TV 40D3500M

Good evening,

how should I call this board? It's like a junction box. The black cable is going to the main board, one of the small connector with ribbon cable is going to the button control board, and the second one to the IR board. I have noticed that not able to turn on the tv from the buttons, also while touching this board the TV starts automatically. It happened a few times.

Is the black semiconductor a schottky diode or transistor? I can read something like H1A, not sure if it's labeled as Q1 or D1. I have no reading from the central pin to the left one. Sorry, I have no microscope yet.

[jazzman72]

Re: Haier LCD TV 40D3500M

it's a transistor. I have reading from the base to the collector and base to emitter. All good with components on this board but still while touching it the TV starts automatically.