7" Screen Flashing White then constant- after upgrade

I have had the screen I bought from Pimoroni attached the the Rpi2 for a month working fine. Although the touch screen fails to respond to touch when the PI is not touched for an hour or longer the only way I have found to bring back the touch input is to restart.

When I do a sudo apt-get install update then upgrade after reboot screen flashes on and off every second or so then stops flashing with a white screen.
I can communicate via ssh and I am running jessie.

I tried many things, eventually I wiped the SD card and put on a working image.
A week later I thought I would try again to upgrade, just in case it was something random. Now the white screen is back.

Anyone else have this problem or know the cause, because I am a bit worried about doing this all over again.

Many thanks

This is something you should probably bring up on the official Pi forums too, with any luck it’ll come to the attention of someone who knows what they’re doing :D

Right now I’ve neither had it, or know the cause, but I’ve got a few SD cards I could try upgrading to see if I can replicate when I find the time.