When I turn on my imac, it chimes and then stays on a gray screen. I have tried to use command r, shift, and cleared the pram several times. Any suggestions
We don't know what Mac model or OS it's using, and I guess you've read the Apple kb article? Mac OS X: Gray screen appears during startup https://support.apple.com/en-ca/HT204325
Have you got a compatible bootable drive you can use to test it??
Have you tried with any and all not needed peripherals disconnected, or using a Safe Boot Mode??
Got an Apple shop or good Apple Authorized shop close by you could take it to???
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