Raspberry Pi 7" Touch Screen: Touch Not Working


#1

Hi all!

I recently purchased a 7" Touchscreen for the Raspberry Pi, and after connecting everything up, I had no problems - everything just worked. Now, I recently needed to switch out the Raspberry Pi, so I took off the female-female cables going from 5V, GND, SDA, SCL on the controller to the Pi. I then took out the ribbon cable from the Pi, inserted the new pi, and re-attached everything. All of my connections seem to be correct, and the display works fine, however, the touch does not. Sometimes the mouse flickers around, occasionally clicking on random icons, otherwise staying still. I looked at some other posts on the net of people with similar issues, and they usually found it to be a power problem. I highly doubt this to be the case, as my PSU is the approved Rpi one, and I was using it with the screen before the touch function ceased to work. Any advice/help would be greatly appreciated! The screens aren’t cheap so I’d really rather not have to buy a new one!

Thanks for the help!


#2

What Model(s) PI? You only need to use the SDA SCL pins with the early Model A and B Pi’s. Not needed if its an A+, B+, 2B, 3B.
The small ribbon cable going from the display to the display card is the one for touch. I’d double check it to make sure it didn’t come lose. Maybe even reseat / reconnect it.


#3

Ah ok - seems I don’t need SDA and SCL.
I’ll try reseating it tonight.
Thanks for the help!


#4

Having those 4 pins there confuses a lot of people. Plus having the 4 jumpers in the box. I don’t think hooking them up hurts anything, not 100% sure though. I never used any of the jumpers. Mine was wired to a 2b, and now a 3B.


#5

I took out the touchscreen connector, and replugged it in. Below is a photo of the connection. Is it not properly in?

Unfortunately, the problem persisted. Could anything else be wrong? Or did I simply not plug it in correctly?
Thanks anyway


#6

Looks OK too me. I’m guessing you took the DSI cable out to do that so its not that either. You would have reconnected it during reassembly. Do you have the display in a case / frame? I ask because some of the early ones had issues with the bezel moving or coming off. That should be fixed by now though. My Bezel slid down slowly over time.


#7

I haven’t added a frame to the screen, but there is the standard black casing.


#8

Ok, the glass front with the black edge is what slid down on mine. I had no case or frame around it. I now have brackets holding it in place.
When you swapped Pi’s did you also swap the SD cards? Putting the original working (sd card) install in the replacement Pi?
What model PI came out and what model went in?


#9

I have already tried putting the old pi back in, and tried swapping sd cards. They’re both pi 3’s


#10

That begs the question, why did you swap out the original Pi 3B?


#11

It sounds like a hardware issue, something happened during the Pi swap, electro static discharge maybe?
As one last test I would make up a new SD card with a fresh download of Raspbian. If it still doesn’t work its a hardware issue. I would then reseat all the cables one last time, being very careful to get them all in nice and tight and straight. How long have you had it?


#12

I’ve now tried a fresh SD card, but to no avail. I guess it must be a hardware problem. I’ve only had it for maybe a month or so.


#13

One was given to me for this project, and had slightly different colorings on the clips for cables, so the difference was noticeable. I was supposed to use that one for this project, and thus needed to change them out.


#14

Most suppliers have a 30 day return policy etc. If you’ve had it less than 30 days you may be able to return it and or get a free replacement.
Ok, no issues with the original Pi. I’ve swapped Pi’s on mine a couple of times. Upgrades to a newer faster model, 2B to a 3B etc. Still working fine, other than my bezel issue. I’ve had mine for a couple of years. It see’s fairly regular use in the summer months. Occasional use in the winter.
Bummer yours quit. I don’t have any other suggestions other than giving everything a really close look. Maybe one last complete disassembly and reassembly.