I will mention that I am only going through the steps once you have disassembled the phone according to the various guides available on the Internet.Namely, the official HTC service manual or this Russian site here:http://www.pdacenter.ru/razborka/razbor-htc-touch-diamond/
There are plenty of guides on the net on how to disassemble the HTC Diamond, but little about replacing the LCD/Digitizer (hence my write up here!).
I apologise that I have not taken pictures at every stage of this process, but I will attempt to explain everything in as much detail as possible. Some pictures I have managed to take are a little blurry, but hopefully you get the drift.
Once you have managed to dismantle the phone to this point, please follow on with this article. At this point, the screen is still glued to the chassis (very tightly!).
To proceed, you will need to pry off the screen. People have recommended using credit cards, which will do the trick nicely once you have managed to find an opening to leverage from. Hopefully, if you have bought your replacement tool they have given you some sort of plastic tool to lever with. The tool on the left works best.
At this point, you will pretty much have to use the lever and a credit card to pry the glue loose. If done successfully, you will have something that looks like this.
Now at this point, you could try and separate the LCD from the digitizer if you only bought one or the other. I suggest that you replace both the LCD and digitizer as there is a high chance that you will not be able to separate them without breaking one or the other. This is just my opinion but there have been people who have successfully done this. If you manage to separate them both, you’ll need to desolder the connection between the LCD and digitizer (4 contact points on a ribbon cable – can be seen on the left in the image below).
The image below shows the silver foil and plastic insulation removed from the rear of the LCD/digitizer unit. Remember the order in which you peeled off the insulating tape and the silver foil! I will explain the problem I had a little later.
For me, I bought a new LCD and digitizer separately, so I had to solder the 4 contacts on the left myself (notice the arrow). This wasn’t too hard to do if you have ever soldered stuff before. Just make sure there is no shorts between the contacts. To avoid this work, you should buy the LCD/digitizer preassembled as one unit.Once you have put together the LCD and digitizer, you will need to remove any of the scratch protective plastic layers off them. Put them together as they’re suppose to be and then stick them back into the chassis. You will need some sort of glue to make the digitizer stick to the chassis. When I pulled mine apart, a lot of the glue stayed on the chassis so I simply popped the digitizer back in and pressed firmly to make it stick. This is not recommended though, as a drop of the phone will cause the digitizer to fall out!Assuming you have figured out some way to make the digitizer stick to the chassis, you’ll notice that the LCD screen also needs to be stuck to the digitizer in some manner. The way I achieved this was to tape the LCD to the chassis with thin strips of electric tape. This stopped the LCD from moving around.
Putting it all back together
You will need make all the ribbon stick to the back of the LCD for tidyness (as above). To do so, I peeled off the double-sided tape from my faulty unit and re-used it.
When putting the silver shielding tape back on, please remember that it is conductive and can cause shorts. I spent ages wondering why my digitizer wouldn’t work and finally realised I forgot to put the yellow insulating tape back on before I put the silver shielding tape back over the ribbon with the 4 contacts that I had to solder (see picture below)!
When you are putting it back together, there is a point where there are 2 sets of ribbon cable that need to make contact with a floating circuit board that sits on top. These two contacts need to be secured properly, and the best way to do it is to view it from side on and use a thin flat head screw driver to firmly press in those contacts. The image below shows the side on view I’m talking about.
The two parts I am referring to are these:
When putting it back together, follow the service manuals or just remember what you pulled apart.
I suggest that before you put everything back together entirely, that you slip the battery in and give it a quick test at this point.
With any luck, the phone turns on, the LCD screen lights up, and the digitizer works! I hope this article helps some people out there who are wondering how to change that screen.