Haier L32F1120 Green but no go

[IanTV]

Hello! I hope to get some help with a Haier L32F1120. It has a green light but does nothing when the power button is pushed, just stays green and no picture or sound. I had a look at the power supply and no bulging caps or anything that looks like it got hot so I tested the voltages at the plug and they are all there as to what is printed on the board next to them so I'm kind of at a loss on what to check next.

[paulstef]

Re: Haier L32F1120 Green but no go

Do you mean when powered up the green LED turns on immediately and it stays lit?

When powering up the TV it should turn green then red. Then when pressing the button it should turn green.

[IanTV]

Re: Haier L32F1120 Green but no go

My mistake it's actually a blue light and turns on when I plug the set in and does nothing with power or any other buttons.

[paulstef]

Re: Haier L32F1120 Green but no go

In your picture of the control board, upper right corner there is a connector with two wires. Do they go to the inverter? Are they called something like DIM, BLK etc? If they are, what's the voltage on them?

Do you get a backlight if you press and hold the power button for about 10sec?

[IanTV]

Re: Haier L32F1120 Green but no go

Next to them on the board it says c251 and c119 and yes they go to inverter. No backlight while holding button in.

[paulstef]

Re: Haier L32F1120 Green but no go

Next to them on the board it says c251 and c119 and yes they go to inverter. No backlight while holding button in.

what does it say on the inverter board. what is the voltage measured on them?

[paulstef]

Re: Haier L32F1120 Green but no go

you can download the manual from here

[IanTV]

Re: Haier L32F1120 Green but no go

BK ADJ and no voltage.

[paulstef]

Re: Haier L32F1120 Green but no go

Ok, just to make sure:

- ALL voltages from the PSU are ok and the LED turns blue when powering on the unit and stays blue when pressing the power button.

Then the problem seems to be the main control board. It either does not recognize you pressing the button or there is something else wrong with it.

There is a schematic of this board in the link I posted.

[budm]

Re: Haier L32F1120 Green but no go

So no 24V on CON2? Can we see the whole back side of the unit so we can see how all the boards are connected together?

[IanTV]

Re: Haier L32F1120 Green but no go

Yes, as soon as plugged in the light comes on and stays blue. And I double checked the voltages and all seem ok from the PSU.

[IanTV]

Re: Haier L32F1120 Green but no go

Yes, I have 24v

[budm]

Re: Haier L32F1120 Green but no go

Per schematic, what DC voltage do you get at pin 5 (Power on/off, this signal is generated by the main board and it is sent to the power supply board to turn on the 24V AND 12V power supply section) of J15 of the main board when power switch is activated? It should toggle between <1V and >2V when power switch is toggle on and off.

[IanTV]

Re: Haier L32F1120 Green but no go

For some reason I can not download that manual. the pin marked ON/OFF i get 5.24v does not matter pressing button or not. I even disconnected it and same.

[budm]

Re: Haier L32F1120 Green but no go

Right now it stuck high, that is why you are getting the 12V and the 24V. The main board is the problem at this point. Have to look further on the main board, checking the voltages of the LDO (Low Drop Out) regulator ICs will be a start.

[IanTV]

Re: Haier L32F1120 Green but no go

Ok, how can I do that?

[budm]

Re: Haier L32F1120 Green but no go

Please read and report the reading in the format as instructed. I see 3 (the device with big tab on top and two legs on the bottom) of them on the board so far.
https://www.badcaps.net/forum/showth...999#post300999

[paulstef]

Re: Haier L32F1120 Green but no go

For some reason I can not download that manual.

schematic starts here: http://www.manualslib.com/manual/513...page=26#manual

[budm]

Re: Haier L32F1120 Green but no go

Here is the service manual.

[IanTV]

Re: Haier L32F1120 Green but no go

Thanks for the manual, the readings are in the pic.