Pimoroni 7" Touchscreen Flashing Test Pattern


#1

I have a new Pimoroni 7" Touchscreen connected to a Raspberry Pi 3 Model B V1.2.
I know the Pi3 works - it has been tested and updated using HDMI and a separate monitor. However, when I plug it into the independently powered 7" touchscreen all I get is a flashing, fading test pattern. See the attached pictures. Any suggestions?


Thanks in advance.
Andrew
I’m only allowed one image. However, the test pattern flashes and fades in and out when seen live.


#2

Here is another picture:


#3

And one more:


#4

This suggests that there’s no video signal reaching the display. Are you sure that the ribbon cable is the right way round? Try flipping it the other way round, i.e. so that the copper contacts are inserted into the connector the other way round. Let us know if that works…


#5

Sandy,
Thanks for the timely help. I’ve flipped the ribbon around which gives the same result. If I flip the ribbon over, the screen is blank. Do you think the ribbon might be faulty?
Andrew


#6

Here’s a link to a video of the screen in action:


#7

Could you take a couple of photos of the ribbon cables connected to both the driver board and the Pi, just so that we can sure they’re properly seated in the connectors, please?


#8

Here they are:


#9


#10

They look fine. What power supply are you using?


#11

Two standard UK(220V) plug to Micro-USB connectors. I have the Y connector Pimoroni sold me - and I think it works properly - but I stopped using it while troubleshooting. The RPi and the Screen are powered separately.


#12

Any other suggestions? I suspect the unit is broken and its time to send it back.


#13

I might be barking the wrong tree but it looks like the Pi is going through a perpetual power cycle loop in your vid. What is the LED activity on the board like when this is occurring?

… Try with the ribbon cable link and without to compare the LED pattern, not sure it will tell a story but perhaps it will.


#14

Rogue,
I can’t believe it, but it is suddenly working. I disconnected the ribbon to compare the LED patterns and then reconnected it and suddenly its working. Amazing. You have a Midas touch.
I suspect the ribbon - despite numerous reseatings - is suddenly in the correct position,
Thanks Rogue and Sandy for your help.


#15

Follow on. Regrettably, the LED is back to doing the same thing. I can’t figure out what is causing it. I’ve given up and order another one. Better luck with this one I hope.


#16

If you believe it’s faulty, and you purchased it from us, then contact support@pimoroni.com and they should be able to sort out a return and refund on the new one that you bought. It’ll be interesting for us to test the faulty one.


#17

I’ve got the new one. It works really well. No problems at all. Since the old one did work at one point, I’ll hang on to it and try to figure out the problem. Its the linux hacker spirit.