Raspberry Pi 4 Display flashing on and off

I just bought a Raspberry Pi 4 a few days ago but im already having issues with it and im trying to ascertain whether its a hardware fault or something I might be doing wrong.

Current OS is Ubuntu 23.04 desktop

So currently the display output from the Pi is turning on and off and now its predominantly off, I manage to get ssh access whilst it was showing in the beginning but like I said there’s no display output most of the time.

I presumed it was the hdmi adapter or cabling issue so I purchased a Ugreen hdmi to micro hdmi cable but the issue persists.

for the cable im using an apple iPad usb-c to usb-c.
for the power supply ive tried an apple 20w and a 30w laptop power adapter which both support 5v 3amp
which results in the same situation on both power supplies, and I don’t think its a load issue because the cpus are going above 20% on all cores.

Any ideas?

I’d give Raspberry Pi OS a go. That should tell you if its a hardware or software issue.

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Ill give it a go now on another SD card and see how it goes

Question: the Pi4 when first issued had problems drawing the correct power when fed with a USB-C to USB-C cable from a power unit’s PD socket. Dunno if that fault still exists (it was missing resistors).

If you could try using a.n.other power unit or power bank with USB-A output and connect your Pi4 using a USB-A to USB-C cable - see if it is simply a power supply (connection) issue.

There was an issue with, I believe, the E marked USB C cables. If this issue had been posted on the Official Pi forum, you would have been inundated with “use the official power supply” replies.
The first release of the Pi 4 had the USB C ID resistors incorrectly wired up in a none standard way.

I managed to figure out what the issue was in the end.
It wasn’t the power supply because I’ve got the newer model of RP4B.
It was ironically the third-party case that I was using.
When I got the pi in the post, i put it straight into the case before I even powered it up, my error.

So, after you said to try a different operating system, I did and at first it had the exact same “fault”, but then it occurred to me, may be the case was bending the PCB, because it’s a passively cooled case and it was pretty tight when you sandwich it together.
So I popped the PCB out of the case, and as I did that it was still plugged into the HDMI and I noticed that it wasn’t pushed all the way in because of the thickness of the wall of the case.

Soon as I push the HDMI all the way in, solid signal, no issues since. It was probably protruding maybe 1mm but I guess that was enough.

So when I screwed the case back together, I pushed the board inside the case as far to the side as I could, and then clamped it with my hand, and tightened it so it would stay in place, so now when I plug it in, it has no problems.
The walls of the case are basically too thick in my opinion.

It’s this case if you’re curious.
Geekworm Raspberry Pi 3 B+/ 3B Case, Pi 3B+/ 3B Aluminum Alloy Passive Cooling Case Housing for Raspberry Pi 3 Model B+/Raspberry Pi 3 Model B (P252) https://amzn.eu/d/ahlXzdc

Hm, they also sell a Pi4 case. Or did you just post the wrong link?

Must be the wrong link, a Pi 3B case will not fit a 4B.

Yeah I just posted the wrong one, there’s a rp4 version also here https://amzn.eu/d/0Mt6xmV

Despite this small issue, it’s actually a great case for the price

I have the Red version of this one, and like it.
Aluminium Heatsink Case for Raspberry Pi 4 – Rhodolite Red (pimoroni.com)