iMac 27 2011 No power

[javier_herart]

Hello!

can you provide some guidance on how to check the PSU (614-0446)?

Thanks

 

[2informaticos]

Do you get any voltage?

 

[javier_herart]

With the board disconnected I get 1.2V in one pin and 1V in another pin.

With the board connected nothing.

 

[2informaticos]

Can we know where???
Use MLB schematic for the power connector.

 

[javier_herart]

I was able to get another PSU, now different issue:

MB: 820-2828-A
With graphics card installed:
LED501: ON
LED502: JUST A LITTLE "SPARKLE" (DA UN DESTELLO Y SE APAGA)
PP12V_S0_MXM: 0.440V (DIODE MODE)
PP3V3_S0: 0.310V (DIODE MODE)
PP5V_S0: 0.353V (DIODE MODE)


With graphics card NOT installed:
LED501: ON
LED502: ON
LED503: OFF
PP12V_S0_MXM: 0.450 (DIODE MODE)
PP3V3_S0: 0.314V (DIODE MODE)
PP5V_S0: 0.357V (DIODE MODE)
FANS KEEP ON

 

[2informaticos]

Check starting in SMC bypass mode, with graphics card installed.

Should be good to test with known good MXM card.

 

[javier_herart]

SMC Bypass same issue:
LED501: ON
LED502: JUST A LITTLE "SPARKLE" (DA UN DESTELLO Y SE APAGA)

I will try to get anotherd card to test, in the meantime, is there anything else I could check?