Why does screen go black on MacBook Pro A1126 during start up?
On start up initially the Mac symbol appears on start up screen after a few seconds the screen turns black - power cable attached and on amber - battery seems to be taking a charge. Also on forced start up there is a long beep. the laptop recently does get very hot on prolonged use. Any ideas?
Connect to an external monitor. If that works you problem is in the internal display chain. You have to work through connectors, cables, controllers and display to figure out which is bad.
If the external doesn't work at all you have a GPU/logic board problem… the DIY fix would be to replace the logic board.
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