820-00165 Magsafe Blinking

[Instafixx]

Hello,
Namaste!

I have a Macbook A1466 820-00165 with No Power Issue.
PPBUS_G3H was at 8.15V. No Light on the charger.
We ahead and did a SMC Reball.
Now getting 8.6V on PPBUS_G3H. But the Magsafe light blinks. First Green then Orange. It blinks after 5-6 seconds.
Not getting any fan spin also.

Please help me out here.

[rookieme]

Re: 820-00165 Magsafe Blinking

CPU reball or SMC reball?

[Instafixx]

Re: 820-00165 Magsafe Blinking

CPU reball or SMC reball?

Apologies.

SMC Reball

[mon2]

Re: 820-00165 Magsafe Blinking

Blinks and then what? Sounds like it is power cycling?

Check /replace the DCin bridge cable between the magsafe board and the main logic board.

Check the voltage to ground of the SPI flash rom.

Received our 4th A1466 unit this week to repair.

[Instafixx]

Re: 820-00165 Magsafe Blinking

Blinks and then what? Sounds like it is power cycling?

Check the voltage to ground of the SPI flash rom.

Received our 4th A1466 unit this week to repair.

You mean U6100 ? Getting 0V on all Pins of the U6100

The Light just blinks on and off. Nothing else.

Another info - The machine is drawing 36mA. But no short on PPBUS or S5_HS line.

[Instafixx]

Re: 820-00165 Magsafe Blinking

Blinks and then what? Sounds like it is power cycling?

Check /replace the DCin bridge cable between the magsafe board and the main logic board.

Check the voltage to ground of the SPI flash rom.

Received our 4th A1466 unit this week to repair.

Replaced the Cable and the board too. Still the same.

[mon2]

Re: 820-00165 Magsafe Blinking

Remove the battery and test again.

What is the voltage of PPBUS_G3H? Is it stable or turns OFF / ON in a cycle?

Is PP3V42_G3H stable?

Voltage of each pin on D7005 ?

Tested with another known good power adapter?

Update:

From:

https://repair.wiki/w/A1466_2015-201...9D_MacBook_Air

[Instafixx]

Re: 820-00165 Magsafe Blinking

Remove the battery and test again.

What is the voltage of PPBUS_G3H? Is it stable or turns OFF / ON in a cycle?

Is PP3V42_G3H stable?

Voltage of each pin on D7005 ?

Tested with another known good power adapter?

All Voltages are without a Battery only.
PPBUS_G3H is stable
PP3v42 is stable

D7005

On Customer's Adapter

Pin1 PPBUS_G3h_R is 0v
Pin 2 PP18V5_DCIN_ISOL_R is 14.6 to 14.9V
Pin 3 PPVIN_G3H_P3V42G3H is at 14.7V

On a Known Good Adapter

Pin1 PPBUS_G3H_R is 8.6V
Pin 2 PP18V5_DCIN_ISOL_R is 15.1V
Pin 3 PPVIN_G3H_P3V42G3H is at 14.7V

Getting a stable Light on the charger now.
PPBUS_G3H and PP3v42 also stable.

But Still no Fan Spin. 0V on u6100

[UPDATE]

This blinking magsafe is also happening when using a Knock-off charger. Also the customer's adapter is also a Knock Off Adapter. Its looks like an Apple one. But its a copy adapter.

[Instafixx]

Re: 820-00165 Magsafe Blinking

Remove the battery and test again.

What is the voltage of PPBUS_G3H? Is it stable or turns OFF / ON in a cycle?

Is PP3V42_G3H stable?

Voltage of each pin on D7005 ?

Tested with another known good power adapter?

Update:

From:

https://repair.wiki/w/A1466_2015-201...9D_MacBook_Air

i went through this. PPBUS_G3H is a has reading .101 (Meter in 2k Mode).

[Instafixx]

Re: 820-00165 Magsafe Blinking

[UPDATE]
PM_BATLOW_L is always 3.3V Checked at R1410 without the Battery.

Replaced R1410 but still the same. Is the Q3000 Mosfet that is causing this issue?

[mon2]

Re: 820-00165 Magsafe Blinking

PPBUS_G3H is a has reading .101 (Meter in 2k Mode).

101 ohms to ground resistance? That is too low.

Remove the fuse on this rail and check this resistance to ground again on BOTH sides of the removed fuse PCB pads.

Post the measurements.

[Instafixx]

Re: 820-00165 Magsafe Blinking

101 ohms to ground resistance? That is too low.

Remove the fuse on this rail and check this resistance to ground again on BOTH sides of the removed fuse PCB pads.

Post the measurements.

Yes you are right.
After removing the fuse.

Meter Reading to Ground
PPBUS_G3H is 409 ohms
PPVBAT_G3H_CHGR_REG is 104 Ohms.

[Meter is 2k Mode and Red to ground]

[mon2]

Re: 820-00165 Magsafe Blinking

These are still low readings for both measurements.

Suggest to verify the measurements with another meter and be sure the meter is in resistance mode, use black on ground.

If the values remain about the same, then check for any liquid damage in this area. Clean and remove with alcohol on a cotton swab. Confirm again the fuse is removed as this will isolate this rail.

Do you have a thermal camera? If yes, power up and check on who heats up in this area. Is it a cap before the fuse?

The downstream after the fuse (consumer side) is also a low resistance but study the up stream, producer side of this power rail for the root cause.

[Instafixx]

Re: 820-00165 Magsafe Blinking

These are still low readings for both measurements.

Suggest to verify the measurements with another meter and be sure the meter is in resistance mode, use black on ground.

If the values remain about the same, then check for any liquid damage in this area. Clean and remove with alcohol on a cotton swab. Confirm again the fuse is removed as this will isolate this rail.

Do you have a thermal camera? If yes, power up and check on who heats up in this area. Is it a cap before the fuse?

The downstream after the fuse (consumer side) is also a low resistance but study the up stream, producer side of this power rail for the root cause.

Have put back another fuse.

Checked with another meter

Getting 17M Ohms on both sides and it kept on reducing.
Black to Ground

Dont have a thermal camera. Should we just inject 1V on the PPVBAT line and see what is getting hot?

[mon2]

Re: 820-00165 Magsafe Blinking

These new measurements are drastically higher values than reported earlier. If accurate, these measurements are ok and are not of concern.

If you measure under 1k ohm readings on either side of the fuse, then you have a partial short to ground.

Confirm the voltage to ground on this fuse. Confirm if the voltage is stable or does it pulse / cycle on / off / on.

[Instafixx]

Re: 820-00165 Magsafe Blinking

These new measurements are drastically higher values than reported earlier. If accurate, these measurements are ok and are not of concern.

If you measure under 1k ohm readings on either side of the fuse, then you have a partial short to ground.

Confirm the voltage to ground on this fuse. Confirm if the voltage is stable or does it pulse / cycle on / off / on.

Voltage is stable at 8.6V.

[mon2]

Re: 820-00165 Magsafe Blinking

Measure the voltage to ground of ALL_SYS_PWRGD.

Is it stable?

[Instafixx]

Re: 820-00165 Magsafe Blinking

Measure the voltage to ground of ALL_SYS_PWRGD.

Is it stable?

ALL_SYS_PWRGD is at 0V.

[Instafixx]

Re: 820-00165 Magsafe Blinking

Measure the voltage to ground of ALL_SYS_PWRGD.

Is it stable?

So i checked the 11+1 Pre-requisites for this A1466 and found these 2 Missing.

PM_DSW_PWRGD
PP3V3_SUS

Tried replacing the U8020 but still the sane.

Any help ?

[mon2]

Re: 820-00165 Magsafe Blinking

From Rossman forums:

Lift U1950 and check for corrosion.
Also remove Q8150 and check again ALL_SYS_PWRGD.