[SOLVED]IMAC 820-2494-A , This board don't turn ON!


New member
Hey guys,

This board don't turn on, only green light on the LED 1. I try to turn on by a short pad and no lucky .. Any some tips for this cancer issue ?

thank you


Staff member
Check Power Sequencing Block Diagram and post some voltage values there.
Don't forget to check L7920 voltage...


New member
PP1V1_S5_REG - 1.113V

PP3V3_S5_REG - 3.373V

PP5V_S5_LDO - 4.985V

PP12V_S5 - 12.05V

ALL S5 voltages ok! This is no first time i have this issue in imacs. usually this machines leave without a solution!! because i say this issue is a cancer! ty for reply!


New member
No shorts in rails.. And i call to costumer and he say the machine turn off and never turn on... You have any more idea ?? thank you


New member

PM_PWRBTN_L - 3.35 and when i toggling goes to 0.18V and don't turn on.. I think it must be a little problem..
Hi, please share how you fixed the problem, I have two board with exactly same issue, only first led is on, there isn't any visible damage under microscope


Same model, same symptoms.
Checked all the rails and got the same values as OP.
Did you manage to fix it or threw it away?