820-01700 no power

[Kyle93]

This arrived with no power. When plugged in you get the low battery symbol but nothing else. No liquid damage. PPBUS_G3H is 12.80V. PPDCIN_G3H is not shorted.

Read on another post battery is not required for this board. When battery is disconnected the board only goes up to 0.20amps and drops down to 0.02. No backlight on screen like when battery is connected.

Tried DFU restore which completely successfully since data was backed up prior to failure but no changes.

What should be checked next?

 

[2informaticos]

Try 96/140W charger...

 

[Kyle93]

Already using a brand new original 96 watt charger

 

[Kyle93]

Would a 140w charger make a difference in this case?

 

[2informaticos]

Without battery, all USB-C ports have the same behavior?

140W is the charger recommended by Apple for this model, but even 87W must charge the battery.

 

[Kyle93]

Yes, all ports have same behavior. They all go up to 0.40amp before dropping to 0.02amp

 

[Kyle93]

When battery is plugged in it will go up to 2.50amps before dropping to 0.02 when low battery icon appears on the screen

 

[2informaticos]

With battery connected, CPU voltage (VCORE) goes off, once battery logo disappears?

 

[Kyle93]

Yes. Starts at 0.790V drops to 0.260v goes up to 0.395v then drops to 0v

 

[2informaticos]

Check ohm resistance over C7020/23.

 

[Kyle93]

2.1ohm after replacing all of them.

 

[2informaticos]

Is the battery charging?

 

[Kyle93]

No, same problem. No change

 

[2informaticos]

test the board alone on the desk, only charger connected.
Check if VCORE still goes off, or remains around 0.5-0.6V aprox.

Use 96/140W charger...

 

[Kyle93]

Board alone on desk with only charger connected VCORE remains at 0v

If battery is connected, vcore is 0.780V before dropping to 0v in a few seconds

Using 96W apple charger

 

[2informaticos]

Check some SMC sensors output level, page 53; VD0R, VP0R, ID0R, IPBR.

 

[Kyle93]

Solved after replacing the battery. The other post with similar issue that claims this board boots without a battery is incorrect.

 

[tcampbell34]

I have worked on a few on these 820-01700, and have found that some will boot without the battery (it will be slow and have high fan spin) and some do not boot at all without a battery, and only shows a low battery symbol. I have no idea why this is though. I actually have one of these now that boots without a battery.

 

[2informaticos]

Thanks both for feedback.
I hope more members read the thread and take notes...

 

[rvanpruissen]

I have worked on a few on these 820-01700, and have found that some will boot without the battery (it will be slow and have high fan spin) and some do not boot at all without a battery, and only shows a low battery symbol. I have no idea why this is though. I actually have one of these now that boots without a battery.

Can confirm. I have one in front of me that does nothing on the bench (20v, 0.07A), but when connected to a battery just boots.