820-3476 fan spins for about 2 seconds then stops and repeats

[No-Clean]

820-3476 fan spins for about 2 seconds then stops and repeats for as long as it is connected.

This machine was liquid damaged and taken somewhere else were all they did was a ultrasonic run.

U 7100 was corroded a bit so I replaced it, but same thing still.

 

[No-Clean]

PPbus is 12.96 when the fan first starts to spin, pp3v42_g3h is a 3.42v steady even when the fan stops for a second.

 

[2informaticos]

12.96V w/ or w/o battery?

Check which big coils get voltage (or pulse at least) in the 2s.

First try starting in SMC bypass mode.
Next try complete NEW BIOS file; do NOT clean ME from original.

 

[JohnB8812]

If 12.96 on just the charger, that is a little high. Might be worth replacing Q7130 and Q7155 with the ISL6259 at the same time to see if any change. Also check resistance between pins 17/18 and 27/28 of the ISL6259 first.

 

[No-Clean]

2informaticos 12.96 no battery, SMC bypass board stays on, will try new BIOS soon

 

[No-Clean]

JohnB8812 Thanks for the tip, after checking diode mode on pins 17/18 and 27/28 pin 17 was 0.610 and not 0.140, the problem was pin 3 of R7150, to do it right I replaced R7150 after cleaning the pads well. Muchas gracias!

 

[JohnB8812]

Working now?

 

[No-Clean]

Yes working now, but I have a new issue, the battery charges really really slow, coconut battery is telling me that it is charing with 4watts, back to troubleshooting

 

[JohnB8812]

Try known good battery. Could be bad battery. Also do an SMC reset.

 

[No-Clean]

Known good battery and 2 SMC resets, same problem, could it be something I repaired/broke?

 

[No-Clean]

I will look for a video how to troubleshoot slow charging issued and see if I learn something.

 

[2informaticos]

What is now the exact value (ohm scale) between pins 17/18 of ILS6259?

 

[No-Clean]

17 0.135ohms red on gnd
18 0.133ohms red on gnd
Between the 2 pins 0.004ohms

 

[2informaticos]

I doubt you can measure 0.004 ohm (4 miliohm).
I suppose to be 4 ohm, which is OK.
In case 0.004 is diode mode reading, that could be wrong; aprox 8 ohm real value.
Some DMMs shows half value than ohm scale in diode mode!

Post PPBUS voltage and battery percentage reported by OSX.

 

[No-Clean]

I have to revive this post as this MacBook is charging super slow, I check what U7100 area and R7150 where I did some work but all looks well, how do I make sure sure the battery is receiving enough/proper current?

 

[2informaticos]

Try to reply the questions...

 

[No-Clean]

Yes that will be a good start.

PPBUS is 12.58v, Battery is 12%, it does charge but super slow, same with new battery and SMC resets.

V

alue (ohm scale) between pins 17/18 of ILS6259 is 3.9ohms​

 

[2informaticos]

Post Q7155 voltages with charger and battery, both connected.

 

[No-Clean]

Q7155: Pins 1--5 11.48v, Pin 4 3.94v

 

[2informaticos]

Looks like battery issue then.
Try known good one, even older; new chinese batteries are crappies.
Q7155 is ON and allows battery charging.

However, post SMC_DCIN/BMON_ISENSE levels.
ALso try PRAM reset.