跳转到主内容

Model A1312 / Mid 2011 / 2.7 & 3.1 GHz Core i5 or 3.4 GHz Core i7 Processor, ID iMac12,2

708 个问题 查看全部

No diagnostic led #2

My iMac won’t power on no fans no or anything all I get is LED #1 when I plug it in and when I press power button LED #2 does not turn on. Any recommendations would help.Thanks!

Power supply is good I’m guessing logic board? Also I have tested it and ran through Apples steps to solve this issue if anything I’m starting with replacing the logic board. Refuse to take it in cause it’s worth less than what it is to fix it through any company Apple or third party.

-Kyle

回答此问题 我也有这个问题

这是一个好问题吗?

得分 1
添加一条评论

1个答案

最有帮助的答案

@greezy91 it could still be a power supply issue. LED 2 will only turn on when it gets the power from the power supply. So start with that before you replace the logic board.

LED #1

• Indicates that the trickle voltage from power supply has been detected by main logic board.

This LED will turn ON when you connect the iMac to a working AC power source. The LED

will remain ON as long as the computer is ON or asleep.

• When computer has been correctly shutdown, the LED#1 behavior may differ:

• - If a startup event is scheduled in System Preferences/Energy saver, LED#1 will stay ON after

a correct shutdown,

• - If no startup event is scheduled in System Preferences/Energy saver, LED#1 will turn OFF

and will stay OFF as long as power cord is kept connected and AC power source is present.

Disconnecting the power cord and plugging it back will turn back this LED ON , even if

computer is still off.

• After disconnecting and reconnecting the AC power source, this LED could remain OFF if

the AC power source is missing or disconnected , if the logic board is disconnected from the

power supply or from the AC receptacle, or if the power supply board is faulty.

LED #2

• Indicates that computer is turned on. This LED will be ON as long as computer is turned on

(but is not asleep) and power supply and voltage regulators are working correctly.

LED #3

• Indicates that computer and video card are communicating. This LED will be ON when

computer is communicating properly with video card. If LEDs 1 and 2 are ON and you heard

the startup sound, but LED 3 is OFF, then the backup battery (on back of logic board) may

need to be reseated, or the video card might be installed incorrectly or needs replacement.

LED #4

• Indicates that computer and LCD panel are communicating. This LED will be ON when

computer is turned on and video signal is being generated. If LED#4 is ON and there is no

image on display, then the LCD panel, the LED backlight board, or the cables between LCD

and logic board or backlight board might be installed incorrectly, or need replacement.

这个答案有帮助吗?

得分 3

1条评论:

@oldturkey03 I took it to a 3rd party computer repai to get fixed and they replaced the power supply and it did not fix the issue and they said it would be 600-800 bucks to put a new-used logic board in so I decided to do this myself thank you for the reply and I’ll do my best to do some more test to find the issue

完成的

添加一条评论

添加你的答案

Kyle Greer 将永远感激不已
浏览统计数据:

过去 24 小时: 0

过去 7 天: 0

过去 30 天: 8

总计 1,267