X22 motherboard in X20?

[GnatGoSplat]

I know there are physical differences, but is the X22 motherboard electrically compatible with the X20's LCD if I use the X20 LCD cable? How about keyboard?

[ajkula66]

First of all, there are different LCDs that came with X20. If yours is VGA (800x600) I wouldn't even bother with it. If it's XGA (1024x768) it should be compatible with X22.

Keyboards are the same between these two as far as I can recall.

Frames (bottoms) are different, though, and you may have some seious issues there.

[GnatGoSplat]

Thanks, I might give a mobo swap a try. I'm almost at the end of my rope trying to diagnose a non-functioning backlight after having replaced the inverter and trying different CCFL tubes. X22 mobos are cheaper than X20 ones on eBay for some reason or another.

Mine is XGA, btw.
The X22 mobos on eBay that I found also come with the case bottom.

[Noblunts]

It should work after different tubes and inverter boards. Did you stick a mulitmeter in the inverter output? Is it giving any voltage off?

[GnatGoSplat]

My "new" inverter from eBay won't work at all, but the fuse on it is not blown. I don't think it's putting out any voltage, but I don't know. I didn't think you can measure the output voltage of an inverter for 2 reasons: 1. It's in the kilovolt range. 2. Inverter will shutdown without a load. I could be wrong on both counts, that's just what I've picked up reading various forums and Google.

My original inverter has a blown fuse. If I bypass the fuse with a jumper, the backlight will work for about 1-second. It will work and stay lit if I bypass the fuse and feed it 10V from an external power supply (it normally gets 16V). The transistor on the inverter gets quite hot, but that could be normal for all I know. The only thing I could think of is maybe 16V is too much power causing the inverter to overload, so if that's the case, something must be blown on the motherboard. That could explain the new inverter not working too... perhaps the new inverter has better protection circuitry where it won't even turn on if it detects excess input voltage. However, I did try feeding it 10V also (and everything in-between 0 and 16V) and the most it will do is make the backlight flicker for a split second.

I don't know why my "new" inverter doesn't work at all though.

[Noblunts]

Check what the motherboard is putting out and if it fluctuates or overvolts and whatnot. You could probably pull spec sheets up on the inverters and see what they should be getting in/out. You're right you can't measure the voltage coming out because there is no load.

Your ebay inverter probably sucks for the same reason my 'brand new oem battery" is at 70% capacity after 9 charge cycles. Check solder around the long coil thing (on the inverter board) and make sure its not cracked and that there are no cold connections. If you have another cable I'd try that too and see if anything changes. Other than that you're probably SOL unless you can figure out what's wrong with the mainboard and replace whatever smd stuff broke.

[GnatGoSplat]

Yeah, part of the problem is I can't find any data sheets or pinouts anywhere to tell me what voltages the inverter should be getting. It's getting 16V, but I don't know if that's too much or okay.

I almost need another laptop just to compare voltages between the two.

I already checked everything that looks like a transistor or diode for shorts and found none. Nothing gets unusually hot, nothing charred on the motherboard, nothing has holes or weird lumps, and I even went over it with a magnifying glass.

It did cross my mind to fudge-fix it with some resistors in place of the blown fuse to drop voltage going to the inverter!