A1502 820-3476-A rebooting

[hgoncalves]

Hi,

I have an A1502 820-3476-A that keeps rebooting when loading OSX. The client told me that first, the cam stopped working, and them it just starts to rebooting.
Already replace the disk, but with the same results. I've notice a bit of corrosion on the U1900 and I've lift it up and soldered back again , but with the same result.

Booting without the cam doesn't solved the problem.

Can you help?

 

[piernov]

Check R2042. Try without R2030.

 

[2informaticos]

Did you try USB macOS?
Also try in safe mode and SMC bypass.
Worth to try known good BIOS too.

 

[hgoncalves]

Removing R2030 seams to have worked.
It boots again! Thanks!
Do I need to leave it without the resistor, or can I check some components to make sure if the cam can be saved?

 

[piernov]

Did you check R2042 first? You can also try to replace U1900.
If there are some instabilities on the clock it can cause the camera IC to crash, and in turn crash the camera driver and cause macOS to reboot when it tries to load it.
By removing R2030, the camera IC is turned off so camera won't work but at least it doesn't crash.

 

[hgoncalves]

Yes, I checked R2042 and it was OK. 3.3v goes through it to the U1900.
I'll replace U1900 and see what happens.

Thanks!