T23 will not show anything on LCD

[RealBlackStuff]

Got a T23 with a problem.
It works perfectly on an external monitor. I have swapped the inverter and LCD-cable with known good ones. Same result.
Tried a known working LCD from another T23, still no picture on the LCD.
Even swapped the mobo, still no dice.
Checked the micro switch on the I/O board, seems OK.
Is there something else on the I/O board that could prevent an LCD from working?
I don't have a spare I/O board.

[graya25]

Sounds like your backlight went out in the LCD. This can be fixed with a little soldering and the CCFL (don't know if this is right) backlights should be fairly cheap. The motherboard is fine, and if the inverter has been tested to be good, it has to be the backlight.

[RealBlackStuff]

I replaced the whole lot, except the I/O board, hence my question.

[tfflivemb2]

I'm sure that you tried this already, but it isn't very clear from your post....did you replace the LCD cable?

I am not aware of anything on the I/O board that would prevent the LCD from showing something...which leads me to my next question. Do you have a dim image, or no image at all? If there is no image can you tell if the screen is bing lit up? (ie. power to the inverter)

[RealBlackStuff]

Yes I did replace the LCD cable, and even the whole LCD unit.
I took another T23 apart and tried that mobo in it, it worked fine.
So I need to replace the I/O board in the original T23 to get it sorted.
It could still be the micro-switch on the I/O board, but I can't find how to test that, let alone find another micro-switch

[vanaya]

I don't have an I/O board from the T23 but I do for T20/1/2. Is there more usb ports, any differences?

For T20, T21, and T22 I/O Card P/N 26P8023
I/O Card with Conformal Coating P/N 08K3373

For T23 I/O Card Assembly for T23 P/N 26P8006

I would be glad to send you one for shipping only of it helps you.

[RealBlackStuff]

Thanks, that's very kind of you, but I ordered one from fleabay already.
Those T20/21/22 boards are not compatible anyway: 1 instead of 2 USB ports, different openings in the back, etc.

[jronald]

Not directly related but here it is
http://kihwal.fayoly.net/proj/t23_bl.html

Ron

[RealBlackStuff]

Thanks Ron, I've done CCFL replacements already. The Hitachi screens are the worst, because you have to fold them open to get at the CCFL. The Samsung or the LG/Philips are much easier (compared to Hitachi).
But I deviate. The CCFL (or even the whole LCD assembly) was not the problem, the I/O board is/was. They sent me a wrong T20 board, and I'm still waiting for the T23 board (hopefully tomorrow).

[T23FUN]

Here's a shot in the dark.
It looks like the hardware has all been swapped out. So could it be a setting in the control panel for the monitors that resides on the hard drive? Maybe the LCD panel is turned off or not selected?
Good luck!

I donate my time to a local middle school where the teachers bought a few T23's. Now I know enough to be dangerous. ;-))

[A_senki]

Upper side on the mobo, near to the LCD cable's seat there is a small smd fuse (it has only one letter: "N").

elektronika.megasix.eu/wp-content/uploads/2007/11/dscf1026.JPG

If that fuse went wrong, LCD's circuit not got power and entire screen black (not very dim, when no backlight).

You can replace it with a 100mA, 0805 sized smd fuse.

[RealBlackStuff]

I just realized I never finished posting...
It worked fine after I got another I/O board and put that in.

@A_senki: thanks for mentioning that, didn't know that also was a fuse.