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Does yours have VCORE cycling or just the rest?

Not another one only good for the parts drawer ? Ill try another bios tomorrow just to see and possibly flux and reflow the entire left side of the board either side in case it’s something with a bad connection that might be impossible to spot. Maybe chuck it in the oven before totally giving...

Might be a dumb ass question but what is it saying by pulsing? Is it simply trying and seeing a fault, so shuts off and has another go again and again or is it missing something that causes everything after that to also pulse?

Is there a way to narrow it down? Split it up a bit to see if it’s before or after something or is it just a case of look until your eyes bleed? should I have a go at sticking 3.3v into PP3v3_S4 to see if anything warms up?

Not bent too bad, no enough to break the screen even. Possibly bent enough to break a connection under the SMC, which I have replaced but still get the same symptoms. CPU VCORE from Pin 1 of C1031 to ground is 10.4ohms

Yeah, probably J9500 connector, 821-1722-A ribbon joining it to the DC board or the DC board itself

Yet another 820-00165 and this one came from a bent mac air. Looks like its only bent down the SMC end so hopefully not another dead CPU PPBUS_G3H = sits at 8.59v and drops to 8.3v every 2 seconds PP3v42_G3H = 3.42v stable PP5V_S5 = 5v pulses PP3v3_S5 = 3.3v pulses SMC_PM_G2_EN = 3.3v pulses...

Yeah figured as much. I’ve got a few more 00165’s to do anyway so at least now I have extra spares.

I don’t suppose there’s a way of confirming a dead cpu is there? Like a certain output or whatever. or is 8.6v up it enough of a confirmation

No point in trying to get S4 going then. I’ll use it for parts if there’s no chance with this one.

00165 board with liquid damage MagSafe but no fan F7140 had 8.6v on pin 1 and 0.2v on pin2 but it wasn't blown Stuck 5v onto pin 2 to see if anything warmed up. U7310 was getting warm so swapped that, then I noticed Q7310 on the other side was also getting warm. Swapped it and now PPBUS is...

I gave up checking around and took another U7400 from another board just on the off chance it was also bad. F'ing thing started straight up. No idea why the first swap was bad as it came of a nearly working board that just glitched every time you touched a ram stick of slot. Anyway, thank you...

Checked all resistors around U7400 against another board and nothing seems bad. I took U7400 off a board with a RAM slot issue so I shouldn't have fitted a bad U7400.

CPU is actually getting hot without a heatsink, but I only get 1mV on VCORE

Hi Duke, thanks for replying. Yeah 181k and 150k now.. 12.57v getting to them and 12.29v for U7400 side of R7403 with the same at pin 1 of U7400 12.35v for U7400 side of R7402 with 12.34 getting to pin 48 on U7400. I'm getting no output on pin 24. I'm assuming there should be a voltage going...

U7400 I get: Pin 46, 29, 19 = 5.1v Pin 1 = 12.29v Pin 48 = 12.34v Pin 43 = 0v Pin 11 = 5.1v Pin 6 = 0v Pin 8 = 0v Pin 21,22,23 = 1v I'm stuck

U1800 is warm but still no vcore. On U2650, I get: Pin 1 = 3.3v Pin 2 = 0.04v Pin 3 = GND Pin 4 = 0v Pin 5 = 3.3v

Just found R7402 (CPUIMVP_TONA) was 1.5mohm rather than 150k so swapped that out. Swapped U7400 also. Still no change though

Duke.. Pin 16, 17 on U7200 looked like they had crap on them before I cleaned the board and swapped it so it possibly sent 12v into the 5v line there.

Forgive my ignorance but I'm not sure what secondary coils are. Here are some voltages from what I guess is what you need. As to a USB mouse.. it lights up. Q7950 gives 3.3v on All_sys_pwrgd I'm getting full fan now also. L7520 0v L7510 0v L7550 0v L7330 1.5v L7260 5.3v L7220 3.4v L7100...