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[SOLVED]820-3330, no trackpad/keyboard/bluetooth.

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SMMRepair

Member
Working on another 820-3330 that has a few issues. It has no trackpad or keyboard, and is also missing Bluetooth ("no information" in system profiler). I checked all associated resistors, and they all check out fine. This isn't a liquid-damaged board. PP3v3_s4 is present at pin 22 of J5800 and pin 30 of J5713. SMC_LID is 3.36v.

U2700 measurements:

pin 1: 0v
2: 0v
3: 3.3v
4: 0v
5: 3.3v
6: 0v
7: 3.125v
8: .55v
9: .375v

Surrounding resistors all seem to measure fine. BIOS chip looks untouched. SMC area looks good as well.

Any ideas?
 
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dukefawks

Administrator
All USB for trackpad/keyboard/BT go to the U2700 USB hub. IR port also goes there so probably also dead. Check power to U2700 and the Xtal, U2700 may also be dead.
 
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SMMRepair

Member
Hey Duke, yeah I actually replaced U2700 as the first step (I've seen it fail on several before, and that was the fix). I replaced it and no change, but will try another chip just to be sure.

Will update once I try another one--will be tomorrow morning, about the head out. Thanks for the help so far, duke, really appreciate your insights. Will update tomorrow!
 
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dukefawks

Administrator
Check power to the chip and also the Xtal and it's caps. If you have the chip off you can bridge the incoming USB from the PCH to the keyboard chip to see if the PCH USB port is working.
 
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SMMRepair

Member
Hey Duke, it looks like the U2700 I used to replace the original bad one was also bad after all. What are the odds? Never actually had that happen before (heard about it a few times though). Whew. I was beginning to think this may be an SMC/PCH issue. Thanks, Duke! I appreciate it.

Mark this one "solved"!
 
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