820-01041 - killing CD3215

[Palhano]

The Mac had its logic board replaced in another service with a board that came from China! It arrived to me without working. All CD3215 chips were shorting the PP3V3_UPC, the U3200 had a burn mark.

I replaced the four chips and the Mac turned on again, I tested all the ports, and the battery charged normally. From one day to the next, without use, it stopped turning on and all the chips burned out. Again the U3200 with a burn mark.

Any tips on what could be causing all the chips to burn?

 

[2informaticos]

Do you still have short on 3V3_UPC after removing U3200?
Don't remove all CD3215 chips at same time.

 

[Palhano]

I ended up removing them all. On each chip, the 3V3_UPC line was shorted, when removing the chip, the short ended. I didn't say it, but the U3100 was causing a short on the PP3V3_G3H_RTC line.

Since I already made the mistake of removing them all, any tips?

 

[2informaticos]

Using original Apple chager?
Any corrosion sign on 3V3_G3H_RTC power supply area?

 

[Palhano]

Yes, original charger.

It stayed on charge for around 1 hour. Then I turned it off, took out the charger. Today I went back to test, everything had toasted.

The board is perfect. no oxidation.

Do I put the new chips in and test?

 

[2informaticos]

Check Q3100/200 and the correspondent MOSFETs from the other channels.
You may consider to replace them directly.

 

[Palhano]

I changed what you suggested and put in new chips (C3215). Board turned on again.

Anything to pay attention to in testing?

 

[Palhano]

Board still working. But, WiFi stopped. I found that PP3V3_G3S_WLAN shorted (diode mode 0.008).

When I put it on the charger, the U3730 gets very hot. Is it worth changing?

 

[2informaticos]

You need to change U3710/50 too...