Allegro CX Screen Replacement

About a year ago my Allegro CX screen died. I was in the middle of a time-sensitive project, so rather than explore repair options I bit the bullet and had a new Surveyor+ overnighted to me. I've been using the Surveyor+ ever since, but having the Allegro just sitting there kind of bothered me. I didn't think it was worth having Juniper Systems replace the screen (though I never did actually get a cost estimate), at least in part because I had heavily hacked the Allegro to accommodate a Parani radio. A couple of times I searched for a replacement screen, but came up empty. That puzzled me, because replacement screens for so many devices are readily available, on eBay if nowhere else.

Last week I decided to give it another go, but this time I opened the Allegro to see if I could find a part number. I was in luck, the screen was made by Sharp and had a part number of LQ038Q7DB03 on it. A search on eBay using that info turned up a replacement; apparently the same screen is used in the Motorola Symbol. The cost? A whopping $4.99 plus $3.65 shipping. I figured I didn't have much to lose, so I ordered it.

Here's a photo of the contents of the padded shipping envelope:

Opening the Allegro is pretty straightforward: lay the unit face down, remove the 10 machine screws around the perimeter, then carefully fold the back to the right so as not to strain the internal cable connections. The shot below shows the unit open. (I had already disconnected the cable from the screen to the motherboard.)

The connector cable pushes onto the motherboard, but the other end uses a tiny hinged connector to secure the flat screen connector. There are a couple of itsy-bitsy plastic clips on the hinged connector that broke when I detached them. We're talking really small, maybe half a millimeter. I was pretty gentle, so they may not be designed for reuse. It's not a big deal, as a piece of electrical tape serves just as well to keep the connector "door" from coming open. (I should have taken more pics, but I was kind of in a hurry.)

Getting the screen into its rubber surround and located in the housing is a little tricky, and more photos during disassembly would have been useful. It took me several tries to get it right, but I got there. Reassembling the Allegro is also kind of tedious, at least if you want to retain the strap rings that are located in the 4 corners. They used some little stainless steel brackets that have to sit loosely between the two halves of the case, and getting all 4 into place at the same time requires patience. I never used the strap clips and thought about just leaving them out, but decided to go ahead and take the time to retain them. Once they're in place, it's just a matter of tightening the machine screws.

Then the moment of truth, or so I thought: I installed the battery, hit the on button, and she lit up, running through the boot sequence and loading WindowsCE. That's when I found out that the moment of truth was only a partial truth: The screen worked fine from the keyboard, but the touch function was wonky. I tried calibrating the screen, which involved tapping on a cross as it moves to various places around the screen, but the most I could get was the first two taps, then it wouldn't respond.

I prefer to run SurvCE from the keypad, but I'm not sure I can access every needed function that way, so I'd like to get the touch function working. At worst, I'm out about 8 bucks and an hour or so of my time right now. But I'm so close to having a fully-functional backup data collector that if anyone has some tips about touchscreens, I'd love to learn about them.

Thanks!