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Hi The 820-3435 I've been repairing is mainly done now. Powers on ok, screen connector and cable replaced as well as bunch of passives and the clock chip . Two things are still awry . 1. The camera is not present . 2. The right arrow key of the keyboard is not recognised . Any thoughts...

Thanks John. Yes - not expecting modern magic! I was using the debug pads but nothing doing. Just in case I had the wrong pads, I reassembled the laptop but I'm still getting no spin-up. I'd be really grateful for advice on what next to check.

nope! Replaced the chip this morning, and some resistors that blew off the board during removal. I didn't have the right value replacement for R7271. It's rated at 86.6k (1%) and may effectively create a voltage divider from the internal resistance to the drain of the n-channel mosfet...

The en lines into u7200 were both at 3.3v. But the 5v outputs where at zero. I've taken it off the board for the time being. will test g2_en in the morning. Thanks.

12.56v on ppbus g3h and 0v on sv3_s5

I was trying to solder back a broken speaker/mic connector last night and after finishing that job I found that the board would no longer power up. It's been a faithful companion to me since I bought it in 2009 so I would rather not give up on this one ... All G3H rails are present save for...

Board is working now. Spins up and boots fine. the rtc chip was blown and a bunch of resistors and caps got lost with the air on too high when I replaced it. All 0201s but I was able to replace them all with 0402 from an older mac donor board thankfully. Last problem on this board is that...

I've looked at some images of the boards on google and they all have these components missing. Odd that they are denoted as critical in the schematic.

further to the "missing resistor" of yesterday I see that there are actually a bunch of other mystery absentees. U5440 (listed as a current sensing FET - INA212), R5440, C5440 and C1924 are all missing. Like the No Stuff resistor, all the pads are shiny (ish - nicely coated with a layer of 5...

Thank you John. I had seen that but, not being an entirely native English speaker, I had not put the proverbial 2 and 2 together and realised that meant what you said. Now that you write it, it's rather obvious!

top left is an ambiguous concept here John! but if there is confidence in the dot and confidence in the boardview pin 1 notation then I guess that it's my mind playing tricks on me and the chip is oriented correctly. It look jarringly wrong vis a vis my memory of when I removed it. As luck...

In hunting around a board I find that there is a resistor on the schematic and boardview (R1906) that seems to connect the 25MHz crystal pins (SYSCLK_CLK25M_X2_R and _L) serving U1900. It's rated at 1MOhm. The pads look clean and unused. and electrically the resistor doesn't look like it...

Hi can anyone share the orientation of the clock-chip on the 820-8435 board? Or a datasheet for the chip (SLG3NB148CV)? thanks Justin p.s. yes -- took the thing off, stopped for a cup of tea and then realised i didn't make a note. and matching the dot with pin 1 on the boardview just...

Thanks Duke parts ordered so I'll report back when they're on the board.

I took the clock chip off and checked before reflowing it. It looked fine. The original gunk went with the removal. Would absence of ppvrtc prevent power on?

thanks for the replies. Appreciate that I will need parts. Mouser supports my area of france adequately, if not rapidly. resistance to ground from PPVRTC_G3H is 161.5kOhms on U5110 the voltages are: pin 1 3.33v pin 2 0 pin 3 3.3v //PP3V42_G3H_SMC_SPV pin 4 1.8v...

first post ... please be gentle (my hair is already very grey). I am trying to repair a mac air mid 2013 with an 820-3435 B logic board. Wine spill on right hand side of keyboard. some noticeable corrosion gunk on the board but all looked rather old; so probably predated the recent spill...