I've started a petition urging Apple to acknowledge the M1 iMac display defect and provide free repairs for all affected devices. If your iMac is showing these symptoms, or if you believe Apple should stand behind their products, please consider signing and sharing: https://change.org/imac_m1_screen Together, we can help bring attention to this issue and push for a proper resolution. Every signature helps show Apple this isn't just an isolated problem.
I recently did a teardown to replace the home button on an iPhone 4. When I powered it back up and saw "No Service", my heart dropped. Fortunately, after reading this forum and others I went into field test mode (*3001#12345#*) where I noted that the statistics were last updated in 1969. After failing to change the date in iOS 7, I turned on WiFi and joined my home network. In seconds the date was updated and then the phone joined the GSM network with ease! Hope this helps others.