Chosen Solution
Yes, I know it’s 2021, but this is still my workhorse, with SSD and tons of RAM, cracks in plastic shell and some destruction aroung magsafe. Sorry if my story would be a bit too long. First, the cord near magsafe plug deteriorated, started to be hot and finallly plummeted. Since it is hard to buy original power adapter where I live I went to aftermarket and got a decent quality replica adapter that made my trackpad act erratically so I just cut the cords and soldered back the original adapter and a magsafe replica cord. It seems to have a chip in it since the machine recognises the adapter’s serial number and stuff. It shows all those green and amber lights and charges battery well. Now I can plug and unplug the magsafe cord normally, it works as designed, but when I move the plugged macbook around (being closed with a NoSleep app preventing it from hybernation) and accidentally pull the power cord slightly, the thing suddenly shuts off completely. No white light in front, no any light in magsafe. I unplug and place the magsafe back, still no light. I can boot from battery, but to make it work from the adapter I need to unplug the adapter from the wall socket and wait for some time and only then it brings back green or amber light again. Once again, sorry for a long explanation. Could anyone please give me some clues what’s going on ? Is it something wrong with an aftermarket magsafe plug, maybe it’s a magsafe board, or the original power adapter is malfunctioning ? How is it possible at all that macbook shuts off with a battery installed ? I taped the magsafe cord to the body to prevent it from moving in its place but hey, that’s inconvenient.
Sounds like you MagSafe connector has failed! MacBook Unibody A1342 MagSafe DC In-Board, Apple P/N 922-9176 and here’s the guide MacBook Unibody Model A1342 MagSafe Board Replacement
Your first mistake was using a clone charger, since they tend to fry the motherboard due to a lack of proper protection mechanism. More then likely, this did damage the DC-In board as they tend to arc them to death. However, the damage often extends to “hidden” logic board damage that gets worse over time and fatally kills the motherboard, or damages it enough you need to repair or replace it. I would start with a DC-In jack and see if that helps. If not, reset the SMC and NVRAM and see if that helps. If not, the motherboard was damaged by the charger. There is a bit of a catch with this unit, however: in many cases, the polycarb series tends to be a total loss when they break, due to the age and depreciation. In addition, a serious chipset limitation which was caused by the nVidia MCP79/89, so blame nVidia for this for hard limiting it and leaving out a SATA III FW upgrade path. Between the age of the unit, and MCP79/89 limitations and 10.13 hard stop, your money will go further on a Mid 2012 13" with new HD cable. Yes, you need to change the cable due to chassis wear and many having a SATA II cable with a SATA III chipset. If you do get the board repaired, make sure it’s significantly cheaper then a newer unit like the 2012 13”. The issue with the MCP79/89 chipset (9400M=MCP79, 2009/320M=MCP89, 2010) is BOTH UNITS have a fatal SATA limitation - they DO NOT SUPPORT SATA III, II max. What this means is Fixed III drives (which are becoming more common) means you need to check the specs if you keep this unit in service and install an SSD. In addition to the SSD issue, these can only run up to 10.13 comfortably. For these two reasons, it’s usually better to upgrade once they fail when possible. If you’re in a situation you have to repair it, keep the limitations in mind and pay for parts accordingly. As much as I like my rMBP… the LCDs are kind of expensive so you need to be prepared. It’s a nice unit (and the panel color rendition is amazing because it’s LG IPS), but you cannot your carry your HD to a Retina. Even still, I usually recommend anything else due to the cost of LCDs unless you’re prepared for the cost. Retina life isn’t for everyone, but those who can own a Retina tend to be much happier with them.
