Model numbers UN40EH5300F UN40EH5300F UN40EH5300FXZC
This TV would reboot on it’s own after a few minutes. Badcaps posts indicate possible failure of the wifi module. When I went into the network settings, it froze the firmware and it could only be reset by unplugging the TV, I had a WIDT20R BN 59-01148B module from a scrapped TV so I replaced it. The TV no longer rebooted but it couldn’t find any wireless networks when I ran the setup. Used modules on ebay are around $50-$60 USD but I was able to find compatible ones on Aliexpress for under $20. My parents UN46ES6100F has the same issue (can’t find networks) so I ordered two.
With a new module installed, the TV was able to find available networks. I did have an issue since it could connect to my router but couldn’t connect to the internet. It appeared that the IP Setting for DNS was set to manual, so once I changed it to automatic, it connected.
Update: The wifi module in my parents TV failed again and it can’t find any networks which was the original problem. Not sure if the fault is in the main board but not likely to replace it again.
Update 2: Had restart problems reported on model UN55F6800 UN55F6800AF and a little online research shows it uses the same wifi module.