Acer H243H Power Board

[Ipodder77]

Hello,

I have an Acer H243H that the backlighting went out on. After disassembly it was confirmed that the backlights are indeed bad. The plan now is to replace the ccfls with leds. The problem is that the led lights require a new/separate inverter board that has four wires that need soldered to the power circuit board. Many other power boards are labeled where the brightness, on/off, GND, and positive power are located. This board has none of that labeled. Does anyone know how to locate these four spots? Is it even possible?

1)GND
2)Postive power
3)Brightness
4)On/Off

Pictures of the board are attached.

Thanks

[budm]

Re: Acer H243H Power Board

Here is the service manual that shows the pin out.

[Ipodder77]

Re: Acer H243H Power Board

I found the brightness and on/off pin on page 47, though I'm having trouble finding the pin out for power.

If it helps, my goal is do something like this "http://www.ebay.com/itm/Monitor-CCFL-LED-Back-Light-Conversion-Strips19-20-21-22-23-24-inch-repair-A188-/231335684787?pt=LH_DefaultDomain_0&hash=item35dcae6ab3"

[budm]

Re: Acer H243H Power Board

What is the input Voltage requirement of the LED controller/driver board? The one in you loink can support up to 30V so the ACER should be able to do it easily, just have to tap off the Inverter power supply section, at the two legs of the 24VDC output filter cap C830 (around the top right section of the diagram).
You should also remove the two power MOSFETs that drive the Inverter transformers.

[Ipodder77]

Re: Acer H243H Power Board

The voltage requirement is 10-30V.

The MOSFETs in the attached picture?

Also, am I correct in the placement of the "brightness" and "on/off"?

I greatly appreciate your help!

[budm]

Re: Acer H243H Power Board

"The MOSFETs in the attached picture?" Yes.
"Also, am I correct in the placement of the "brightness" and "on/off"?" The brightness on this may be PWM (Variable pulse width 10%-90%, 90% = max brightness) instead or analog (0~+5VDC, +5 = MAX brightness). You will have to check that line to see when you make the brightness adjustment.
Same thing for the ON/OFF, you need to find out if ON = >2.5VDC (active HIGH) or 0V (<1v) = ON for active LOW.

[Ipodder77]

Re: Acer H243H Power Board

Great! Thanks very much. I couldn't have had all this figured out without your help! I'll get the parts ordered and report back how it all went.

[Vadrotan]

Re: Acer H243H Power Board

I have the same monitor, what symptoms did your monitor exhibit to lead you to open it up? If my issue is similar to yours I may try what you're doing, can't exactly hurt it at this point.

Mine makes a chirping/humming sound and the backlight has started to flicker.

Regardless, I am interested to find out how you eventually fair with this project.

[Ipodder77]

Re: Acer H243H Power Board

My initial symptoms were that a picture would show up for a split second and then disappear. With the use of a flashlight I could see that the picture was still there. I believe it did make a slight humming sound. I was initially hoping that the backlight problem was due to bad capacitors as it had been with previous monitors in the past (different models), but after I opened up the lcd panel I found that the backlighting ccfls were black where they had burned out and one was in fact broken.

My choices to fix this were either buy new ccfls or leds. I ultimately decided to order leds since they were cheaper and more readily available. I'm now waiting for the parts to come in.

[Ipodder77]

Re: Acer H243H Power Board

The parts came in and the project was a success!

I ordered the LEDs and inverter board from ebay very similar to my link above. An attached picture shows my board after the wiring. Though I purchased a less expensive item, the pictures in the following link helped me greatly.

http://www.ebay.com/itm/Monitor-CCFL...item35dcae6ab3

One thing I found out the hard way was that you should never just rely on the wire colors for the wire placement. It ended up every wire was opposite of what it should be. Black was actually wired positive and red was negative on the inverter. By the time I figured that out there was some resoldering to be done.

The On/Off is functional as well as the brightness. I had them switched as well initially, though out of the 14 pins in that location they are soldered onto pin 7 and 8. (I honestly forget right now which one was which, sorry)

I placed the inverter on the side as seen in another one of the pictures.

In all I now a great working monitor. I couldn't have completed this without the community here. Many thanks.

Vadrotan, if you have any questions or need more detail about anything I did I'd be glad to answer them. Unfortunately, I forgot to take pictures of the LCD panel apart when I put in the LED strips.

[budm]

Re: Acer H243H Power Board

Nice and bright picture on the screen!

[jeffbrown1966]

Re: Acer H243H Power Board

I am working on the same monitor and got ahead of myself and removed some caps before seeing what the are, I am trying to find out the rating on C819, C823, C820,C830 And C501 I have looked at several schematics but it is like the ratings are blurred out. do you or anyone else have a schematic that can I can read

Thank you

[selldoor]

Re: Acer H243H Power Board

Did you take any pictures of your board before you started?

[selldoor]

Re: Acer H243H Power Board

Sorry too late to edit - have you already bought your new caps?

[Ipodder77]

Re: Acer H243H Power Board

I got all my information from the service manual I found here

http://www.manualslib.com/manual/269446/Acer-H243.html

It was blurred for me as well but what I needed was slightly more in focus so I could make it out.

[temppy]

Re: Acer H243H Power Board

The parts came in and the project was a success!

I ordered the LEDs and inverter board from ebay very similar to my link above. An attached picture shows my board after the wiring. Though I purchased a less expensive item, the pictures in the following link helped me greatly.

http://www.ebay.com/itm/Monitor-CCFL...item35dcae6ab3

One thing I found out the hard way was that you should never just rely on the wire colors for the wire placement. It ended up every wire was opposite of what it should be. Black was actually wired positive and red was negative on the inverter. By the time I figured that out there was some resoldering to be done.

The On/Off is functional as well as the brightness. I had them switched as well initially, though out of the 14 pins in that location they are soldered onto pin 7 and 8. (I honestly forget right now which one was which, sorry)

I placed the inverter on the side as seen in another one of the pictures.

In all I now a great working monitor. I couldn't have completed this without the community here. Many thanks.

Vadrotan, if you have any questions or need more detail about anything I did I'd be glad to answer them. Unfortunately, I forgot to take pictures of the LCD panel apart when I put in the LED strips.

are the wires on the pic inverted

[Ipodder77]

Re: Acer H243H Power Board

The picture shows the correct position of the wires. The black wire was positive on my inverter and the red wire was negative.

[temppy]

Re: Acer H243H Power Board

Which pin is the blue wire on

[Ipodder77]

Re: Acer H243H Power Board

The blue is on pin 7 which is the on/off and the yellow is on pin 8 which is the brightness.

[temppy]

Re: Acer H243H Power Board

The blue is on pin 7 which is the on/off and the yellow is on pin 8 which is the brightness.

can you repost the pics bad caps dosnt show the pics