21.5” iMac A1418 the onboard diagnostic LED's not lit
My 21.5” iMac a1418 is dead.
The 5 diagnostic LED's on the main board are all off but the power supply has been replaced.
Any ideas what the problem might be?
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I would first check the outlet and line cord to make sure you have power getting to the system. Then check the system socket for damage.
With the cord disconnected from the AC outlet I would trace the cord contacts to the socket lines from within the case where it connects to the power supply using a continuity tester (not power).
Then carefully test the power output at the logic board header you should measure the DC voltages per the schematics and board view. Are the present?
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I don't have a schematic of the logic board but I can measure +12Vdc on three of the pins on the logic board "header".
@noname35512 - Not good😫 Your logic board has a problem. You’ll need to get the schematics and board view drawings to trace things out.
You’ll need to help us a bit here as there are too many versions of the A1418 system and many use very different internal architecture! Review this listing to find yours A1418 iMacs
由 Dan 完成的
sorry about the lack of pertinent information.
EMC is 2638
serial # D25LJ2X6F8J3
由 no name 完成的
@noname35512 - I’ve corrected your system info.
由 Dan 完成的