[SOLVED] Chromecast - no signal

[Ketorax]

Hi,
Recently a customer at work returned their TV due to a lightning strike that blew the fuse in the TV. Instead of disposing the TV, I decided to replace the fuse and use it as an extra TV at home. The TV seems to be working fine, except for the issue I'm experiencing with the Chromecast I bought to use with this device.

Specifications:
Grundig 32 VLE 5730 BN
Chromecast 3rd gen.

Issue:
I connect the Chromecast to any of the 3 available HDMI ports and into the wall outlet. After that I turn on the TV and switch to the HDMI source the Chromecast is plugged in to. This is where the issue starts. The TV shows "No Source" even though the correct source is chosen. It seems like the TV is recognizing the Chromecast since it's visible under the "DigiLink (CEC)" settings on the TV, and the TV recognizes that an HDMI cable is connected.
Side note: The board where all the inputs are makes a "buzzing" noise as soon as an HDMI cable is connected when the TV is turned on (regardless of using laptop or CC).

What I've tried:

• Connect my laptop to any of the 3 HDMI ports to see if any of the ports took any damage from the lightning strike. Since this is working fine, I've ruled out that the ports are faulty.
• Connect the Chromecast to a different TV, this also works without any issues.
• Connect a different Chromecast (2nd gen.) to the TV, same issue.
• Plugged the USB powering the Chromecast into the TV USB port
• Followed the troubleshooting steps on Google's support page
• Reset the Chromecast
• Factory reset the TV
• Followed every step mentioned in this thread on Androidcentral (tl;dr: Connect CC USB first then HDMI after CC LED stays white, unplug TV from power while turned on and leave it for 10~ minutes)

I've also read through the entire user manual of the TV which mentions that the HDMI ports are HDCP compatible (read some posts on other forums suggesting HDCP could be an issue), and could not find any other instructions/troubleshooting steps related to my issue.
I've googled this issue for a few days now, and besides the lack of posts of users with the same issue, literally no suggested solution has worked.

I'm starting to run out of ideas and figured I'd ask here in case anyone has any suggestions.
Please let me know if my post is missing any information that might be necessary in order to continue the troubleshooting process.

Thank you in advance,
- Ketorax

 

[Ralston18]

Underlying premise being that the lightning strike only blew the fuse and caused no other damage.

Overall, your troubleshooting has been very thorough and methodical.

Regarding your side note:

"The board where all the inputs are makes a 'buzzing' noise as soon as an HDMI cable is connected when the TV is turned on (regardless of using laptop or CC)."

I would suspect deeper damage.

Is that board replaceable?