820-2936 No Hard Drive

[Puevig reven]

I have a 820-2936 that does not recognize the hard drive. The drive has power but I still get flashing folder. Tried new cable, etc. Everything seems to measure correctly. Any ideas?

 

[XooP]

Had the same issue a couple of days ago, tried a new cable still nothing. What finally woke the drive "recognition" was SMC reset.

 

[RavetcoFX]

Just to rule out the basics, I'm assuming you've tried another hard drive, or made sure that one isn't dead. Try an SMC reset like suggested above, if that doesn't work, Check U4510 to see if it's getting voltage and SATARDRVR_EN

 

[larossmann]

I would suspect the replacement cable since so many bad ones are out there. Once that is ruled out, I would check between J4501 and U4510 where there are a bunch of resistors and capacitors. that's the first place I'd look. The only two times this has ever been an issue for me in the past it was something there.

 

[larossmann]

btw, when I say check, I mean replace... how a capacitor passes the stupid signal your multimeter puts out is different from how it will pass a high speed data line signal.

 

[Puevig reven]

Thanks guys! I have that one at home and I will check tonight!

 

[RavetcoFX]

larossmann what do you think goes wrong with the cables, I have quite a few bad ones as well that were nowhere near any damage

 

[dukefawks]

Copper trace in the bends break. Traces are stretched when they bend the cable. Not 100% sure about the cause but I would say stress corrosion cracking is happening. Very common on copper/bronze that is cold deformed.

 

[Sykulski]

Why are they not breaking in the 15 inch models? Here they are also bended but I don't remember changing one. In 13 inch I change them every day.

 

[XooP]

I have replaced in many 15" MacBook Pros as well, so they do break.

 

[jorge]

They sold a lot more 13" than 15" mbps