[HTC Sensation] dfrau10:
Potential hardware fix

Hi, after two days of struggling with my phone (and months of badly responsing/behaving screen) I have found a solution to these ghosting, etc. problems.

DISCLAIMER: I am not liable for any damage you may inflict to your device by improper handling, disassembling, etc., neither am I liable for any lost warranties you may suffer. These are just my problems and solutions with my phone and its display.

Here I give you some background to my (and many others have it, too) issue:

I have a Doogee F5, and for already some months I have been having a ghosting/overall bad responsiveness of the screen. This was the original screen!

So I ordered a replacement screen from china, it arrived in about a month, and I have changed my screen, hoping that all the issues will be gone. Now I should point out that the original screen was attached using glue, not by using double-sided adhesives, etc.

Well, the ghost touches remained and they were even worse than before! I was searching on many forums for a solution, because in this state the phone was unusable, there was a permanent ghost touch in the lower right corner. I couldn't find a solution for my phone, but I have found some fixes for other phones. It consisted in avoiding bad ground connection between the screen and the ground of the phone.

According to that I went ahead and grounded the display directly to the phone ground, hoping it will be resolved after that. Well, it wasn't, I was only getting more frustrated with more time passing of me without a phone. The ghost touch was even worse - and that is when I knew it was DUE to the connection between the screen and the phone ground. I bought some insulating toluene-based protective coating varnish for finished PCBs, covered the back and the exposed metal parts of the new display with it, reassembled the phone, and the bad responsiveness and ghost touches were gone!

The fix:

The web is filled with people who have similar problems, many of them have the same phone as me, but there are also users of other phones with the same problems, so I came to a conclusion:

The producers of cheaper (chinese) phones often use glue instead of other better insulating adhesives to attach the display to the phone, so over time because of shocks, phone falling, wear, etc. the insulation between the display and phone ground gets weakened, thus allowing these kind of problems, even to devices with original displays.

So now there are two possibilities:

- either ensure the insulation between the display and the phone ground, if insulation is required,

- or ensure good connection of the display and the phone ground (in some phones there are grounding patches and pins, so these are to be checked first) if good grounding is required.

Another factor is the static electricity buildup discussed in this thread, above. That is yet another issue, other than the one I have experienced and am right now describing.

I hope this helps other people with this issue, because it was pretty hard trying to find a fix for this problem.

I should also point out that my display came without the polarizing layer, so the screen shows completely white to a naked human eye, but I was able to retrieve a piece of polarizing film from the old display, so I have to use the phone with self-made polarizing glasses to be able to see anything on there. It is however a nice feature, having a display that nobody except me can read :)