820-00426 Replaced three bad FETS with FDMF6708

[Outofwhack]

Customer brought in a dead A1398 with no visible corrosion.
Inspected it and found one FDMF6808N with a crater - see photo.
Replaced it with FDMF6708 but the other two FET were getting hot as well so replaced all three.
Noticed prior to changing them that their power rail PP5V_S0 was at 6.6v

After 3 x replacement the board still did not start and I noticed all_sys_pwrgd missing.
Tracked this to PP1V35_S3RS0_CPUDDR missing and I replaced U7400 and Q7430

Now the board appears to have retreated to S5 state yet I do see a very short pulse of voltage on FET outputs and all_sys_pwrgd.

I am beginning to wonder why I never get happy fan spinny endings like on the youtube videos! - am I cut out for this?
Where do I go next?

ppbus_g3h	3.3v
pp5v_s5	5v
p5vs4_en	0
s4_pwr_en	0
pm_slp_s5_l	0

 

[2informaticos]

Very likely damaged CPU; overvoltage occured through the burnt FDMF6808 chip.

 

[Outofwhack]

Is there any way to determine any life in the cpu?
Should I see 1.35volts on the output of these FETs at least? After all before I replaced the fets I was seeing 6.66volts on their supply (PP5V_S0) but now the board appears to be in an S5 state!

Could you explain a little about whether the cpu is involved in sending PM_SLP_S5_L high and progressing to lower S levels?

 

[2informaticos]

More than 6V on 5V_S0 could have damaged more things on the board.
That could be the reason board doesn't exit from S5 state now.
So you should check 5V_S3 related components around U7501.

Do you get 3V3_SUS?