820-2850 1/4 fan spin

[Chuck60]

Hi I have a question. I’m getting a fan spin for about 4 seconds I test

PPBUS_G3H 12.55
PP5V_S5=5v
PP3v3_S5 = 3.3v
PP3v3_S3= pulses 0-3.3v
PP5v_S3=pulses 0-5v
PP5VS3_ENTRIP = pulsing 0-5v
PP5VS3_EN= 0-5v

U7000
Pins 28,27 = 20.4 ohms
Pins 17,18 = 3.2ohms

RTC
PCH_CLK32K_RTCX1 =0v
PCH_CLK32K_RTCX2=0v
RTC_RESET_L=3.42v
PCH_SRTCRST_L =3.42v
PPVOUT_G3H_PCH_DCRTC= 1.6v
SMC_CLK32K = 1.6v
PM_CLK32K_SUSCLK = 1.6v

u5388
1 0v Ground
2 0v Ground
3 3.42v
4 12.55
5 12.54
6= 0v Output
I replaced U5388 just in case and same problem there’s No short on CPUVCORE_HISIDE_IOUT .489v in diode mode to ground

thanks for your help

 

[2informaticos]

Any history available?
Did you try SMC bypass mode?

"PP3v3_S3= pulses 0-3.3v
PP5v_S3=pulses 0-5v"
I don't see any note about other S3, or S0 voltage...

 

[Chuck60]

The only visible work done on here is FaceTime area where they ran a trace to the connector. All other s3 and S0 as I remember are pulsing I will test them. I will also retry the bypass mode and it has the same behavior with battery connected. It does charge the battery and the light turns orange

 

[Chuck60]

my apologies it was a cap c8942. That was bringing it down now it chimes but fans spin up full speed immediately.Checked the sensor that are usually knocked off Or damaged but they are intact. I have no keyboard connected as I can’t find one at this moment. I will find one and get back to you

 

[2informaticos]

Run corresponding ASD EFI version and check for errors.
Try known good trackpad and flex.
Also try disconnecting webcam.

 

[Chuck60]

the fan spinning high was keyboard I Have replaced Broken WiFi and lvds Connectors and I’m going to redo iSight traces/connector. The only issue I haven’t dealt with is a “no Bluetooth“ I’m looking at the schematics now to resolve this
But it’s booting fine and Bluetooth and FaceTime are the only thinks left
Thank you for your help

 

[Chuck60]

Camera issues resolved

still no Bluetooth


continuity between u3700
U3700 Pin 1 to 23 of j3401 0.00V
U3700 Pin 2 to 21 Of j3401 0.00v
resistance to ground on j3401
Pin 23 .649v
Pin 21 . 642v

 

[2informaticos]

Did you check L3406?

 

[Chuck60]

Yes it also has continuity I was wondering if I should check it under load but I can get under the connector. Any ideas?

 

[2informaticos]

If you suspect that coil, just solder tiny wire instead...

 

[Chuck60]

Ok the wire didn’t work

 

[2informaticos]

Try another airport card, and flex...

 

[Chuck60]

Resolved damaged trace and pad under choke :/