iPad Pro 11 A2230 won't boot up - stuck at logo

[mon2]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

Post the details of these parts with their values, size, voltage.

Chinaphonefix is a good vendor we have used for ipad parts.

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

D8710 Finally found it on Mouser.com https://cdn.badcaps-static.com/pdfs/...2c4536cde1.pdf
C8073 - 1uF / 35V (0402)

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

This is real hell to dissasembly this PCB.

[mon2]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

Yes, it will be. Find a good youtube video and take your time in the disassembly.

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

So, I finally disassembled PCB. Changed broken diode (I found donor - iphone XSMAX - same value). Removed C8073.

But with no effect. Still the same.

[mon2]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

What is the current draw?

I think your case will be similar to this iphone:

https://blog.rewa.tech/detail/how-to...-on-apple-logo

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

With or without battery connected?
Should I disconnect everything except USB-C?

[mon2]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

Disconnect the battery and using only the USB-C as a power source, does the ipad boot to the same stuck logo?

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

So, now battery is disconnected, there is only USB-C connected.

Still stuck at logo. Current draw is about 120mA.

[fallenapples]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

unplug all flex apart from charge port and screen.

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

Like I said, there is nothing connected except USB-C port and LCD.

[mon2]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

There appears to be very little on this model and topic on the internet.

Remove the USB-C port cable so there is no power to the logic board. Meter in resistance mode.

Measure the resistance to ground of each coil you can probe. Review the coil(s) against the schematic to confirm if they are linked to a local switching power supply rail.

If the resistance is low, there may be a shorted capacitor on that power rail.

Other suggestions are to review the I2C bus devices. It is possible that the OS is stuck waiting on some I2C bus slave device to respond and there may be a disconnect.

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

Well, I think this is impossible, beacause there is no visible pads. See photo.

[mon2]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

Understood. Trick is to find a nearby capacitor that can be probed and is on the same power rail. Since power is removed, all safe to check each such coil.

You are sure the ipad was not dropped? This will result in fractured coils or caps.

[elecsoluces]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

C8073 and D8710 shorted, those 2 components have connection to U8000.
This IC has I2C bus you should check this IC and components around.

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

There is no short. Already checked it.

[elecsoluces]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

Ok no short around U8000 but the IC itself can be the problem

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

Maybe, but I don't have spare parts. So it's better be sure what really cause this behaviour before I'll order it.

[martyjelen]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

There appears to be very little on this model and topic on the internet.

Remove the USB-C port cable so there is no power to the logic board. Meter in resistance mode.

Measure the resistance to ground of each coil you can probe. Review the coil(s) against the schematic to confirm if they are linked to a local switching power supply rail.

If the resistance is low, there may be a shorted capacitor on that power rail.

Other suggestions are to review the I2C bus devices. It is possible that the OS is stuck waiting on some I2C bus slave device to respond and there may be a disconnect.

I started measuring and found that on C812F (PPVDD_S1_SOC) is only 30ohm to ground.

[elecsoluces]

Re: iPad Pro 11 A2230 won't boot up - stuck at logo

You have an image SOC power rails should be good.