Hi. Have an A1466 820-00165 unit with no power / no fan / no chime. Magsafe light goes green / orange cycling. No liquid damage indicators, looks quite clean and not serviced by anyone (yet).
Found that there is no PPBUS_G3H rail. Then noted that 8A fuse @ F7140 is blown. Fuse Pin 1 @ 8v6; Pin 2 @ 0v. That fuse arrived yesterday (Belfuse Fast Blow @ 8A). Replaced with great excitement but now, the rail is about 0v5v and the fuse is still intact.
Have removed the wifi card; removed the SSD; removed the battery. Swapped out the DC / audio board with another - no difference.
Do feel some warmth around L7130 but do not (yet) own a thermal camera.
Any ideas?
Suspecting that something after the PPBUS_G3H is causing excessive current draw and this power supply (U7100) is shutting down.
Bad cap downstream?
Also, a bit confused on what is the expected power rail here. This chassis has 8v6 for PPBUS_G3H (thanks Piernov for the clarity - schematic is not accurate) - when the fuse was OPEN. Yet another tech posted for the same logic board, they have 12v6 on this rail. Can remove the fuse again to confirm that U7100 is still good.
With the new fuse (8A) installed, see 16.xx volts (from magsafe) @ R7005 and this is feeding into the buck converter for the 3v42 rail just fine. But R7006 is @ 0v5 (PPBUS_G3H).
Welcome suggestions. We did recently purchase the Sunshine voltage injector but honestly afraid to use it. Also brought in some of the 'smokey flux' they show in their demos.
Found that there is no PPBUS_G3H rail. Then noted that 8A fuse @ F7140 is blown. Fuse Pin 1 @ 8v6; Pin 2 @ 0v. That fuse arrived yesterday (Belfuse Fast Blow @ 8A). Replaced with great excitement but now, the rail is about 0v5v and the fuse is still intact.
Have removed the wifi card; removed the SSD; removed the battery. Swapped out the DC / audio board with another - no difference.
Do feel some warmth around L7130 but do not (yet) own a thermal camera.
Any ideas?
Suspecting that something after the PPBUS_G3H is causing excessive current draw and this power supply (U7100) is shutting down.
Bad cap downstream?
Also, a bit confused on what is the expected power rail here. This chassis has 8v6 for PPBUS_G3H (thanks Piernov for the clarity - schematic is not accurate) - when the fuse was OPEN. Yet another tech posted for the same logic board, they have 12v6 on this rail. Can remove the fuse again to confirm that U7100 is still good.
With the new fuse (8A) installed, see 16.xx volts (from magsafe) @ R7005 and this is feeding into the buck converter for the 3v42 rail just fine. But R7006 is @ 0v5 (PPBUS_G3H).
Welcome suggestions. We did recently purchase the Sunshine voltage injector but honestly afraid to use it. Also brought in some of the 'smokey flux' they show in their demos.
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