820-3481-a a1419 imac single led is blinking.

[Jeffotskie26]

hello it is my 1st time doing imac
when i recieved this imac totally no led is on. my 1st suspect is power supply
board. after i change it got led 1 is on then when i press the power button the led 2 is blinking.
so i just decided to removed the motherboard on the case and reconnects the small boards battery.
after this now only single light is blinking.
pp12v_acdc is pulsing from 12v-5v
also pp12_s0 is also pulsing from 1v-5v
what should i need to test again?

 

[2informaticos]

Use lab PSU for test.
12V, set amp limit to max.

 

[Jeffotskie26]

thanks @2informaticos i think can on already now got 2 lights on then when trigger power button 3 light shows on.
my psu that i bought is defective, is there a way to fix this?

 

[2informaticos]

So the iMac power supply is the problem?
Find working one.

Be aware about high voltage present on the power supply.
On Internet may find some tricks about classic issues with iMac power supplies.