Working on an 820-2850 that might have a bad SMC...
- 820-2850 board that has pp5v_s0, but the fans don't spin. 3v3_s0, 5v_s0 present; 1v05_s0 is only .03v...which might be the reason why the board isn't powering on. Already replaced C9560 with poly-film cap.
- Pin 1 of C9560 is 1.5v.
- Fans will spin in SMC bypass mode, but no chime or boot.
- Unsure of clock signal--it seems to be called something other than ppvrtc_g3h? Is it the XOUT pin of U2700?
- Green light consistently takes several seconds (5-8) to turn on, but once it does, it stays on and is steady. Tried several known-good DC-in boards.
- CPU/GPU both get warm (normal-warm, not blazing hot), as if they're active, but vcore is not present (0v).
Any ideas? Since I have pp5v_s0 at the fan, but no fan spin, does this mean the SMC isn't communicating properly? Since it controls the fans, etc. No idea how pp5v_s0 and pp3v3_s0 can both be present, but no fan spin? SMC? Sort of a weird one, but it's a 2850, so I'm not surprised...probably a dead CPU or GPU.
- 820-2850 board that has pp5v_s0, but the fans don't spin. 3v3_s0, 5v_s0 present; 1v05_s0 is only .03v...which might be the reason why the board isn't powering on. Already replaced C9560 with poly-film cap.
- Pin 1 of C9560 is 1.5v.
- Fans will spin in SMC bypass mode, but no chime or boot.
- Unsure of clock signal--it seems to be called something other than ppvrtc_g3h? Is it the XOUT pin of U2700?
- Green light consistently takes several seconds (5-8) to turn on, but once it does, it stays on and is steady. Tried several known-good DC-in boards.
- CPU/GPU both get warm (normal-warm, not blazing hot), as if they're active, but vcore is not present (0v).
Any ideas? Since I have pp5v_s0 at the fan, but no fan spin, does this mean the SMC isn't communicating properly? Since it controls the fans, etc. No idea how pp5v_s0 and pp3v3_s0 can both be present, but no fan spin? SMC? Sort of a weird one, but it's a 2850, so I'm not surprised...probably a dead CPU or GPU.
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