Can a 5.1V/1A power supply run a B model + touchscreen?

Question

Hello,

I got a touchscreen for my RPI for Christmas. I haven't touched it in a long time, and didn't do much with it back then, but it booted.

I assembled the screen using one mount, and the incorrect instructions here:

https://www.youtube.com/watch?v=E1lua5mgrJs

Powered up, black screen, nothing bad. Looked at the comments, then the pin diagram, and corrected the jumpers.

Powered up again, black screen.

Thinking I had some kind of power deficit, I removed all jumpers and powered both the screen and the RPI via separate power supplies. Black screen.

Just for fun, I put all the wires back properly and powered both boards seperately. Black screen.

Any ideas?

I wish there was just one small PWR LED on the back of the touchscreen...

shabaz · Answer

Hi Kevin,

You didn't specify precisely which Pi model you have, and the difference impacts the current consumption.

If you're referring to the very first Pi model B, then you'll lack some functionality at the very least (see here https://forums.pimoroni.com/t/official-7-raspberry-pi-touch-screen-faq/959 ) and I wouldn't be surprised if not many people are running this combination (since that first Pi model B is so ancient) so there could be issues.

If you're referring to a Pi 3 model B, then it should work, but very unlikely with a 1A capable supply. A 2.5A capable supply is needed (and preferably the official Pi power supply, since that will have been tested by many people with the Pi 3 and the capacitive touch display).

There are several combinations that can be used to power the Pi boards with the capacitive display. I choose to use the method where the Pi is powered as usual, and the capacitive display is powered from the 40-way GPIO connector on the Pi.

The procedure I followed is documented here:

Raspberry Pi 7” Capacitive Touch Display: Assembly and Enclosure

It is as detailed as I could manage.

Other procedures will work too, but I only tried that procedure and it functions fine as far as I can tell.

There is a thread with hundreds of Q&A in the comments section, to help address virtually all known things that could go wrong during assembly. It is here: Raspberry Pi 7” Touchscreen Display scroll down to the comments section.