topic Re: EOS R8 not displaying through HDMI in EOS DSLR & Mirrorless Cameras

EOS R8 not displaying through HDMI

Ahmedalattar96 — Thu, 25 Dec 2025 17:06:22 GMT

Hi, i have Canon EOS R8 that was displaying it's screen through Video capture card and TV. However, one time i plugged the hdmi coming from camera to usb-powered hdmi splitter and after this moment the camera is not displaying through hdmi anymore and whenever i plug/unplug hdmi cable the screen blink like if it's recognise a signal but returning normal. Everything else is working greatly except this thing.

I upgraded the firmware to latest

Reset the system

Changed the cable

Still not displaying . I'm from iraq so we don't have canon service there

The camera repair shop says that when i plugged the usb power cable to hdmi splitter it returns a power to camera that fried one of the component or shorting it out and i have to replace the entire main board . When i opened it everything looks normal .

Could someone tell me if it's shorted out what is the component that is responsible for this issue so i can replace it to fix the issue

This is the type of main board of R8

Re: EOS R8 not displaying through HDMI

kvbarkley — Thu, 25 Dec 2025 17:54:59 GMT

We can’t troubleshoot remotely, but about the only other thing it could be is that the hdmi connection is loose on the board. You might try resoldering it. If that does not work you will need to get it repaired

Re: EOS R8 not displaying through HDMI

SignifDigits — Fri, 26 Dec 2025 01:56:54 GMT

Just agreeing my my colleague and letting you know that if you were to have burned out a integrated circuit with overcurrent it could very well be one of the integrated circuit chips on the board you would never see damage. The only way to diagnose that would be if you had electrical specifications on each of the connections to test.

Unless you see a cold or damaged solder joint which you can repair, and if your USB device is sending power over HDMI (likey NOT supported by the R8 port), I'm guessing the camera shop is correct and you will need a repair and ensure that any device that you use is fully compliant with the HDMI out-only feature of the R8.

So the specific answer to your question is "No". Nobody here or there, for that matter, can merely look at your board and tell you if you have shorted out that circuit unless there is a melted solder joint. And I expect you would be exceedingly lucky if it were that simple and none of the other components was damaged by an overload sufficient to melt a solder.

Additionally, nobody can tell from your scenario whether you have damaged the main circuit. We do not have the specifics of the USB powered splitter. A powered KVM from a reputable source should not damage your HDMI signal, nor should a passive HDMI splitter cable. But it's certainly possible that your repair shop there is wholly correct and that your device used power over HDMI and the R8 board does not support this.

You could diagnose the HDMI signal via HDMI testing equipment that would range from probably the cost of the repair to more than the cost of the camera itself to answer what is deficient in the signal from the R8. That seems an impractical course of action, however.

I am sorry that our response has likely not helped you in the way that you hoped that it would.

Please let us know how you fare moving forward on this so that we might learn more about this unusual situation.

Re: EOS R8 not displaying through HDMI

Ahmedalattar96 — Sat, 27 Dec 2025 07:58:25 GMT

thhank you very much for your suggestions and advices. since i don't have canon customer service in my country, i'm thinking of purchasing mainboard from a reliable store. how about AliExpress store since it has plenty of these boards are these sites guaranteed? thank you.

Re: EOS R8 not displaying through HDMI

Waddizzle — Sat, 27 Dec 2025 14:55:59 GMT

Aliexpress? Based upon examples that I have seen from customers who purchased far less costly items like toys and articles of clothing, I would say buyer beware.

Canon has multiple web sites that are dedicated nearly every part of the world. Some locations serve multiple countries. Try the link below.

https://global.canon/en/support/index.html

Re: EOS R8 not displaying through HDMI

Ahmedalattar96 — Sun, 28 Dec 2025 09:56:11 GMT

It was That big chipset suspect of being faulty but it's hard to replace so i have to replace the entire board. Thank you

Never use HDMI Splitter with USB Powered to not causing problem like mine.