820-00244 Not powering on

[Shredplayer]

820-00244 Not powering on and i found out C3101 is shorted to ground so i replaced it and got a faint light on D6900 but still no boot no display and cpu not getting warm, i then tested PPBUS_LIO and got 14v and as far as i know this suppose to be a 20v, replace U3100 or Q3100?

 

[JohnB8812]

5 or 20 volts on DC-in? I will warn you all 12" MacBooks end in dead CPU at some point, so beware.

 

[2informaticos]

14V could be correct, depending of charger model.
Post exact voltage for PPDCIN_G3H and PPBUS_G3H.
Do you get 3V3_S5/SUS?
Be aware of CPU short life on these boards.

 

[Shredplayer]

PPDCIN_G3H = 14.8v
PPBUS_G3H = 8.7v
PP3V3_S5 = 3.3v
PP3V3_SUS = 0v

 

[2informaticos]

Check if PM_SLP_SUS_L misses too.
If not present, check all RTC signals (3).

 

[Shredplayer]

PM_SLP_SUS_L = 0v
RTC Signals = 3v

 

[2informaticos]

Can you post ALL RTC signals measured???
Also post PM_RSMRST_L, PM_PWRBTN_L, PM_BATLOW_L, PM_DSW_PWRGD.
Trigger SMC_ONOFF_L (R5225/26 pads) and check for drop pulse at PM_PWRBTN_L.

 

[Shredplayer]

PM_RSMRST_L = 0v
PM_PWRBTN_L = 0v
PM_BATLOW_L = 0v
PM_DSW_PWRGD = 1.2v
SMC_ONOFF_L = 3.3v
PPVRTC_G3H = 3.09v
SYSCLK_CLK32K_PCH = 0.5v
PCH_SRTCRST_L = 3.09v
PCH_RTCRST_L = 3.09v
PCH_INTRUDER_L = 2.78v

 

[2informaticos]

OK, RTC signals all good.

"PM_DSW_PWRGD = 1.2v"
This is bad; check S5_PWRGD.
Also check around U7800, PP3V3_PMICLDO, SMC_PM_G2_EN, PP5V_G3H.

 

[Shredplayer]

As i was testing S5_PWRGD which is 3.3v i notice the cpu is warm so put back the lcd and it booted but after i shut it down and turn it back on, no boot and display, a loose component maybe? reflow?

 

[2informaticos]

Many times CPU gets bent and this generates bad solders on the balls from the edges...

 

[JohnB8812]

Trash dead CPU