Hey there,
getting in line of the "giving making a DIY-Cintiq a try"-ers.
A little
background: Actually I got a drawing monitor some time ago, the UGee 2150. Maybe someone is shaking their head, going "why would that idiot want a DIY-Cintiq then??" Well, it is a mixed bag.
The
screen/hardware itself is very good, as far as I can judge, screen is very crisp, great colors, little heat, pen pressure works ok, little lag, but - and here I am looking at the other half - the
driver is quite special.
Not many options - that I could live with. Calibration is...tricky. I can't get it right, for example I started to fudge on the height after a lot of tries, clicking the pen about five mm below the calibration marks, so the cursor would line up a bit better with the pen tip, as usually it would hover 5mm above it after a finished calibration.
Then, sometimes there is a loss of function - I have to open the driver panel by using the mouse, do a pressure test there, and then the pen would work again for some time. And some other things that were just a bit off, so I found myself more fiddling with tuning than actually drawing, which started to irritate me. Enough that I considered other options, and having used a Graphire and Intuos 2 A5 earlier I did really like the Wacom driver setup.
Now I found an Intuos4 used on ebay for a steal, only had to buy a new pen (got the classic, not the grip pen) and that made me think of trying to convert it into a monitor tablet, so I pounced.
Got a used screen for another 50€, disassembled it, and here I am.
The hard stuff:
Tablet:
Intuos4 XL (PTK-1240) - that thing is huge!
Monitor/Panel:
LG IPS 22MP55HQ, with Panel LM215WF3 (SL)(K1). 21,5", IPS, LED-Backlight, external power source - took some time to find that combination without shelling out too much money. Now I hope it isn't one of the hopeless cases that will always play jitterbells.
Additional stuff: Got a roll of copper tape and alumium tape each, will try both for shielding. Also several sheets of plastic foil for insulation.
I did the usual first, place the stripped screen onto the tablet enclosure to check if the pen signal connects - sadly, not at all.
So I removed the top cover of the intuos, put a sheet of plastic foil onto the digitizer and the screen on top of it - better, pen is recognized, but reading height is very low, I'd say only about 2-3mm above the screen. So possibilities of putting a protective sheet on it are "slim" .. haha. Maybe that will improve with shielding.

on tablet2.jpg (400.65 KB. 1342x1116 - viewed 335 times.)
So, all in all right now: The good - it works, mostly.
Issues:
Jitter: There is some. Very very little in the middle of the screen and towards the top, quite some more towards the bottom (where the long panel-circuirty is) and to the right, where the LED-strip is placed. Which brings me to:
Heat: The LED strip is getting very hot, to a degree where I only left it on for a minute or so, as I started to smell something, likely something being gassed or melting from a plastic by the heat. I had glued the strip(using the remaining glue on its backside) onto the thin black plastic bezel(which I use to keep the panels layers together) that came with the monitor. Originally it was attached to the side lip of the metal backside, but as that had to go of course, now there is no means of getting rid of the heat. I guess I will have to find another way to help with heat dissipation, maybe glueing it to an aluminum sheet angleded outwards?
A minor issue: The LED-strip is not powered by a flat cable, but by some bundled-up wires, which stick out from unter screen (and thereby lifting it up a bit at that corner) due to the angle of the connector. As I can't drill a hole into the digitizer to make room for them, I guess I will try to put the strip at the other side of the screen, so the connector points upwards, there should be more space.
I will take some more pictures and add the next steps planned.
****** Later this day:I re-positioned the led-strip to let the wires go up instead of down. But this does not solve the problem as expected - the top two layers of the screen are a bit wider than the lower ones, which I failed to notice before. To place the LED-strip directly against the diffuser-layer, I will either have to
a) displace the upper/lower layers against each other so there is no "step", diverging from how they were inside the original screen
b) exchange the wires against a flat cable - I found where to order them, but unsure what kind of connector I need to look for.
Also I gave shielding a first try: A piece of copper tape (insulated of course) between the panels circuits and the digitizer. Then I noticed (which may have something to do with it or just me not paying proper attention before): The jitter happens(now?) only to the sides of the screen, but there in almost equal strength. So: Middle of the screen (complete top to bottom) is almost jitter-free(I guess 1-2 pixels at most), at the sides (1-2cm) there is some jitter. Placing another strip of copper tape next to one side gave no change.
Random clicks also only appear in those small side-zones occasionally.
Right now, the tip of the pen doesn't seem to click - the cursor is moving, but no input if I touch the surface... but maybe I only changed something in the driver settings - will try again tomorrow.