Haier L32F1120 Green but no go

[paulstef]

Re: Haier L32F1120 Green but no go

- R270
- drain of Q56
- C425

[IanTV]

Re: Haier L32F1120 Green but no go

Found U25 on the under side of the board. looking for R218 now.

[IanTV]

Re: Haier L32F1120 Green but no go

You need to locate R218 (0 Ohm) and then measure the DC voltage between the Ground (chassis) and the leg of R218, it should have 1.1VDC.

Locate R270. U25 may be an option circuit that may not be used in your TV.

Hard to find for these old eyes. It measures 1.08v on one side and 1.09 on the other.

[paulstef]

Re: Haier L32F1120 Green but no go

Still wondering why you don't get a signal back from your power button while having 5VSTB.

[IanTV]

Re: Haier L32F1120 Green but no go

Would there be something I can try and jumper to get it to start????

[paulstef]

Re: Haier L32F1120 Green but no go

There are always several points from where you can start. Budm recommended checking all voltages. They all seem to be ok.
You can't verify if the uC is running since you don't have scope.

I would then start from the power button. You need to find out how exactly it is connected to the mainboard. Does its signal get to the board? First step.

Once you found that out you can maybe make a jumper somewhere. We are not there yet.

[budm]

Re: Haier L32F1120 Green but no go

I do not see the wiring diagram of the switch assembly to tell us how it works.
The Key pad assembly where power switch is located (connector J7 page 32) has 3 wires, Gnd, KS0, KS1, not sure what J12 where KEY_STBY signal is for.
The manual does not show J12 signals.
Page 9, 10 shows the connectors signals.

[budm]

Re: Haier L32F1120 Green but no go

I see two more sub power supplies (U16, U21) page 40.
Also MCU reset IC U4 page 42 and the Y1 Crystal. I wonder if the MCU is running or not.
So far there are 7 ICs for the power supply:
U12, U13, U16, U18, U19, U21, U25.

[IanTV]

Re: Haier L32F1120 Green but no go

So any other thoughts on this one?

[budm]

Re: Haier L32F1120 Green but no go

I do not have any more suggestion to locate the bad components on the main board.

[paulstef]

Re: Haier L32F1120 Green but no go

So any other thoughts on this one?

You need an oscilloscope for troubleshooting.

[yyzkevin]

Re: Haier L32F1120 Green but no go

I have the same TV with basically the same symptoms. If I connect the power supply to the mains and disconnect all other connections I see only the +5V on the the +5VSTB pin (pin6 i believe on the power supply connector).

When I power it up with the mainboard connected, I can then measure all the correct voltages on all the pins of the power supply. Pin 5 on the power supply is 3.3V which is coming from the mainboard.

The system just sits in this state, the power led is solid blue, and periodically blinks red for a very short time.

I do have a scope and I will check to see if I can identify any life on the mcu. I also have a logic analyzer however I doubt it is fast enough to capture on this.

one thing I keep asking myself, in the service manual on page 59 section 9-2, what exactly do they mean "is power LCD normal?" , are they referring to a solid blue light?

If I follow this to yes, next question is to check voltage on pin5 is high, which it is 3.3V, so it ends there says there is a power supply problem. in this case I am not sure what the issue would be, the voltages certainly all read correct although it does not sound healthy to me, but really I know very little about power supplies.

what gets confusing to me is if I consider that the answer is no to "is power lcd normal?" going down that path first question is to check for +5V on pin6, which is there of course, so the last step on that path is to "check if the oscillate circuit for U8 works normally", which I have not checked.

it is also funny, if you go the other way there, it says if U13 is damaged you should replace U11.... ?

if there is anything specific you want me to check let me know, otherwise I will report back if i find anything.

[sureshbobby]

Re: Haier L32F1120 Green but no go

Hi same issue with my haier same model, i have bad caps , replace them, but same problem, led turns red to solid blue, reading the replaced caps am getting 53v current instead of 35 v reading

[sureshbobby]

Re: Haier L32F1120 Green but no go

Hope i can get some help from you pals

[libyantiger]

Re: Haier L32F1120 Green but no go

this sets have common failure of bad flash ic data you can reprogramm the flash

the problem i am refering to is set have red light of standby but pressing the power button does not reveal any thing and the sets does not seems to "notice " that you reallyy pressed the power button >>>flash is usually 25q32bsig it is chinese flash ic very commonly found in these sets ....google your main board model looking for flash data once found reporgam ur ic and it should be ok