Recent content by ClerkenwellMacs

I have replaced all the components to the bottom and right of the Wifi chip, traces are all fine. Still nothing unfortunately.

That was the extent of the liquid on the board.

Have a liquid damaged 820-01700 No wifi hardware detected within OS, liquid damage around U3730. Are there some base requirements for the Wifi to be detected, nothing looked like it had gone. Thanks!

I am getting 2.2 ohms on PPBUS_G3H with all U7410/20/30 off. I removed them and re-applied individually with no change in ohms. So currently I have U7210/20 and U7410/20/30 off the board and still have the short.

I measured at PPBUS_HS_CPU the first time, have just measured PPBUS_G3H and its the same. Does that sound right or am I making a mistake?

Tried removing one at a time and then both, U7210 Only 1.7 ohm U7220 Only 1.7 ohm Both Off - 1.6 ohm

1.7 ohm ?

Have an 820-00850 A1989 13" Pro 4 Thunderbolt Port. Liquid damage to C7214 only, was totally burned out with burning electrical smell. Shorting to ground for sure. Getting 5.1v on USB No liquid to anything else. Fried CPU? Cheers

Thank you, I have made a few wrong assumptions. Pin 13 - 14 on U7710 was a mistake. I will go over the schematics a little more and work out what I need to measure to check if there is something up with U3900. Are there any technical docs re the T2 logic? I had better get a better...

Is it worth me pulling off the shield to have a look at U3900 and U7800?

All voltages on Page 78 concerning U7800 look good. And it looks as if U7710 is turned on by CPU_VCCEOPIOSENSE_P and CPU_VCCEOPIOSENSE_N so wouldn't expect anything on L7702.

PPVDDCPU_AWAKE 0.79v coming out of U3900 into U7800 Then nothing on big coils. U7710 is responsible for L7702 (I believe) Conclusive but maybe not that relevant. Pin - v 1 - 0 2 - 0 3 - 0 4 - 0 5 - 0 6 - 0 7 - 0 8 - 0 9 - 0 10 - 0 11 - 0 12 - 4.71 13 - 5.09 14 - 0 15 - 0 16 - 0

Getting 0.53v on PPVDDCPU_AWAKE which is below threshold of 0.625 for U7800, right track?

The T2 is involved with everything.. Great! By the looks of it the T2 Chip/U3900 must be powered on for me to have got it into DFU mode but any of the other chips it interfaces with could then kill it and prevent a boot.

Page 69 Values - These all look fine to me. PP3V3_G3H_RTC 3.29 PPVBAT_G3H_CONN 12.56 <-> 0.18 Fluctuates between the two (No battery connected) PMU_ONOFF_L 1.79 PMU_RSLOC_RST_L 3.25 CHGR_RST_IN 0 CHGR_COMP 1.56 UPC_PMU_RESET 0...