# Raspberry Pi 4 Display flashing on and off **URL:** \ **Category:** Support\ **Created:** [July 9, 2023, 1:13pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476 "2023-07-09T13:13:15Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Rivers](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/rivers/32/9942_2.png) [@Rivers](https://forums.pimoroni.com/u/Rivers)\ **Post date:** [July 9, 2023, 1:13pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/1 "2023-07-09T13:13:15Z")
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? ---
**Author:** ![alphanumeric](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/alphanumeric/32/2729_2.png) [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)\ **Post date:** [July 9, 2023, 1:45pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/2 "2023-07-09T13:45:54Z")
I’d give Raspberry Pi OS a go. That should tell you if its a hardware or software issue. ---
**Author:** ![Rivers](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/rivers/32/9942_2.png) [@Rivers](https://forums.pimoroni.com/u/Rivers)\ **Post date:** [July 9, 2023, 1:51pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/3 "2023-07-09T13:51:06Z")
Ill give it a go now on another SD card and see how it goes ---
**Author:** ![neilman](https://avatars.discourse-cdn.com/v4/letter/n/6de8d8/32.png) [@neilman](https://forums.pimoroni.com/u/neilman)\ **Post date:** [July 9, 2023, 8:56pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/4 "2023-07-09T20:56:45Z")
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. ---
**Author:** ![alphanumeric](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/alphanumeric/32/2729_2.png) [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)\ **Post date:** [July 9, 2023, 9:16pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/5 "2023-07-09T21:16:36Z")
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. ---
**Author:** ![Rivers](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/rivers/32/9942_2.png) [@Rivers](https://forums.pimoroni.com/u/Rivers)\ **Post date:** [July 9, 2023, 9:39pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/6 "2023-07-09T21:39:44Z")
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](https://amzn.eu/d/ahlXzdc) ---
**Author:** ![bablokb](https://avatars.discourse-cdn.com/v4/letter/b/ee59a6/32.png) [@bablokb](https://forums.pimoroni.com/u/bablokb)\ **Post date:** [July 10, 2023, 5:43pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/7 "2023-07-10T17:43:06Z")
Hm, they also sell a Pi4 case. Or did you just post the wrong link? ---
**Author:** ![alphanumeric](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/alphanumeric/32/2729_2.png) [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)\ **Post date:** [July 10, 2023, 6:08pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/8 "2023-07-10T18:08:56Z")
Must be the wrong link, a Pi 3B case will not fit a 4B. ---
**Author:** ![Rivers](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/rivers/32/9942_2.png) [@Rivers](https://forums.pimoroni.com/u/Rivers)\ **Post date:** [July 10, 2023, 10:09pm UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/9 "2023-07-10T22:09:36Z")
Yeah I just posted the wrong one, there’s a rp4 version also here [https://amzn.eu/d/0Mt6xmV](https://amzn.eu/d/0Mt6xmV) Despite this small issue, it’s actually a great case for the price ---
**Author:** ![alphanumeric](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.pimoroni.com/alphanumeric/32/2729_2.png) [@alphanumeric](https://forums.pimoroni.com/u/alphanumeric)\ **Post date:** [July 11, 2023, 8:12am UTC](https://forums.pimoroni.com/t/raspberry-pi-4-display-flashing-on-and-off/22476/10 "2023-07-11T08:12:36Z")
I have the Red version of this one, and like it. [Aluminium Heatsink Case for Raspberry Pi 4 – Rhodolite Red (pimoroni.com)](https://shop.pimoroni.com/products/aluminium-heatsink-case-for-raspberry-pi-4?variant=30924235997267)