Mac black screen on startup 2017 upgrade#

Mac black screen on startup 2017 upgrade#

Jefferson said a friend’s iMac had a similar problem due to an imperfect upgrade by a previous owner.

It might cost $100 or more to have someone qualified crack the case and look for signs of failure, at which point unless they’re handy with a soldering iron and it’s something that can be fixed with molten tin and lead, it won’t be worth repairing. I suspect the repair shop only ran hardware diagnostics via software, which wouldn’t reveal this, and didn’t open it up. In movement, it might have been jarred, or the repair facility might be heavily air conditioned or not at all, while Cecil’s home is the opposite. With modern manufacture, that sort of nonsense is much less likely, but given that moving the iMac into a different location made the problem impossible to replicate lends credence. Banging the set jarred the discontinuity in the solid-state circuit that did color decoding. (As a child, my family had a color TV set, but when it heated up, it shifted to black and white. While I haven’t seen this recently, in my youth-when I was more hands on with soldering irons and circuits-it was relatively common to have faults that only materialized under certain circumstances in which heating or cooling caused expansion or contraction that caused a temporary gap in whatever conductive material was passing electricity.

Without laying hands on the computer, my guess is this is an electrical fault that has a thermal component.