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Board chimes, fan spins no display L8304 black and cracked in half replaced it..still no display now 3.3V for 1-2 seconds measured at pin 2 after power applied R8364 look a little worn so replaced it lvds J8300 connector looks good no water damage usb mouse lights up 1.8V at cpu inductors

Working on it. REFLOWED U1950 again Fan spins...4 sec..stop...spin...stop U1950 1: ALL_SYS_PWRGD: 3.33V steady 2: 3.33V and steady PIN 3: 0.25-0.30,1.60,0.25 -----> 2.5V diode mode to ground pin 3 Flip board over onto CPU side. Fan now spins and stays spinning only to return to the...

Yes: 1.66V when fan spins

u1950 area is ugly on this board bare pcb ground plane to the right on the pin 1/8 side of chip exposed i think i have soldered and resoldered that chip 5 times

Voltage pulse on then off: Board now only fan spins once then stops If I plug the magsafe in and out it does it again: Cannot start in SMC bypass mode. Tested the board alone on the desk, without any flex connected; nor LIO flex, just DCIN 5 pins cable. L7630: 1.05 V --> 0 L7620: 5.09 V...

OK sorry informaticos. That was a stupid post. Swapped Q7630. PPBUS_G3H: 8.59V DIODE MODE PPBUS_G3H: 2.86 V to GROUND OHM MODE: 1.59 MOhm to ground Checked all prior solder work Plug in nothing, plug in again...nothing..plug in gain...fan spin... Intermittent fan spin Fan spin..stop..Fan...

swapped Q7630, no change going to look at U7600 now could the inductor itself be bad? also C7630 or R7630 to check

why is resistance so low on cpu inductors ?

DIODE MODE to ground RED GROUND=R BLACK GROUND=B PPBUS_G3H --- 0.121 0.218 -----------R----B L7130 0.121...

L7130 voltage back 8.59V (PIN 1&2) with F7140 removed Short is on the system side U7100 is outputting PPBUS_G3H U5450 PIN 3: 2.5 kO PIN 4&5: 100OHM in diode mode to ground PIN 6: 19 kO Diode mode voltage drop to ground on pins 1&2 of L7310 and L7320 is 0 V Noted Q5510 case cracked open...

done fuse is good: RESISTANCE is 0.7 ohms AS A TEST: removed f7140 0.2V diode to ground pin 1 open on pin 2 THEN OUT BACK F7140 give up on this board? Changed C1212 as it looked bad and was heating to touch C1214 VERY WARM but looks OK

U7100 voltages Resoldered new chip and inspected solders They all look good 1:0 2: 14.63 3:3.95 5:.92 6:0 7:1.22 8: .327 9: .1 10: 3.42 11: 3.43 12: 3.43 13: 3.40 14: 3.40 15 : .05 16: 1.97 17: 1.97 18: 1.97 19: 5.05 20: 5.01 21: 4.07V 22: 23: 1.98 24: 2.59 25: 6.55 26:14.18 27: 15.03 28...

OK I will post voltages I may change the chip I had used a Chinese chip from Alibaba I have a US supplier. Maybe the chip is bad

L7130. ----> 0.117V to Ground pin 1 & 2

L7130. ----> 0.117V to Ground pin 1 & 2 https://boards.rossmanngroup.com/threads/820-3435-ppbus-1-7v.48210/ i should have measured resistance to ground with u7100 removed i used a brand new U7100 ISL chip too When you have a PPBUS_G3H low voltage how the hell do you tell if this is a load...

did it no change PPBUS_G3H is NOT 0V It remains 1.96 V it is being dragged down CPU IS WARM My thought: D7105 Q7180 but I am getting 14V at pin 2 R7120

ok my f up 1.97V 215 O to ground R7120= .1 OHMS 14 V on Pin 1 WENT BACK TO U7100 PIN 24 2.57 V and 103 OHM to ground On a working refernce board: PIN 24 is 10.5 V and 2 MOhm to ground

No water damage per customer Amber light on charger PPBUS_G3H at 1.94V CPU WARM Obvious;y no fan spin U7100: 1: 0V 2: 14.59 3: 3.94 7: 1.17V 8: .326 9: .1 10: 3.43 12: 3.43 13: 3.40 14: 3.40 15: 0.06 16: 1.95 17: 1.95 18: 1.95 19: 5.01 20: 5.0 23: 1.97 24: 2.57 25: 6.52 26: 14.19 27: 14.41...

informaticos: So lets put back R8166 with Q8150 off the board? -----> FAN stops spinning I tried putting back: R8164 R8165 R8166 R8168 The fan, as I said above, goes away. ALL_SYS_PWRGD....goes to 0

Maybe I explained wrong SEQUENCE Remove R8166 ----> NO FAN SPIN Remove R8165 ----> NO FAN SPIN Remove R8164 ----> NO FAN SPIN Remove R8168 ----> NO FAN SPIN At this point all of the above resistors are off this board Remove Q8150 -------> FAN SPIN The only thing that makes the...