External USB with dead SSD can't install OS updates w/o bricking USB drive

[emteek]

2013 Macbook Pro 13"
Coffee killed the native 256 gb SSD so converted over to an external 256 gb USB 3.0 flash drive. Runs great but boots a bit slow. Able to install fresh catalina 10.15.7 by creating a 24 gb extended journaled partition (bootvolume) containing catalina 10.15.7 install file (8 gb) from apple, and a 232 gb APFS partition that I named mymacos. I didn't want to clutter up this page with all the particulars. But I cobbled the overall process together from various geniuses on the interwebs.

The problems start with installing ANY OS updates from apple that pop up in system preferences, software update. I was running fine for about 6 months until I decided to go for Big Sur, upgrade failed, stuck on apple logo for 3 hours, and forcing shutdown ended up to macOS utilities eventually, seemingly it bricked the mymacos partition. Had to reinstall catalina from scratch.

Happy for about 12 hours until I decided to install the latest Catalina 10.15.7 security update, failed, again stuck on apple logo for an hour, again seeming to wreck the mymacos partition, maybe that is the wrong term, but in other words it won't run, boots to macOS utilities after a forced shutdown and PRAM reset after reboots just keep getting stuck weirdly. I can access the mymacos partition using terminal to recover files if needed, but the OS seems kaput. Have tried SMC resets, PRAM resets, booting to wifi recovery seems to run an older version of utilities that doesn't allow APFS formatting so I avoid it. Attempts to run first aid using disk utility don't find problems. The USB drive integrity seems unaffected, I can remove it and install it in another macbook without any trouble and run disk utility.

So now I don't dare install any OS updates. Is there a manual process for updates that is vetted?

 

[glenthompson]

The internal SSD isn’t that hard to replace on that model. Have you considered replacing it so you’re working from an internal drive? Have you tried installing MacOS on the external using a different Mac?

 

[emteek]

I considered replacing the internal SSD but opted for the somewhat less expensive and more thrilling option of booting externally. I hadn't considered installing the OS on another mac, seems like a good idea if there are some key firmware bits that need to be harvested from a native SSD. All my other macs are running big sur at the moment, not sure if that matters. IIRC I was running catalina during the initial development 6 months ago. Forgot to mention that restoring mymacos from time machine backup also failed. At this point I have a slight preference for replacing the SSD for a definitive fix.

 

[chrfr]

I considered replacing the internal SSD but opted for the somewhat less expensive and more thrilling option of booting externally. I hadn't considered installing the OS on another mac, seems like a good idea if there are some key firmware bits that need to be harvested from a native SSD. All my other macs are running big sur at the moment, not sure if that matters. IIRC I was running catalina during the initial development 6 months ago. Forgot to mention that restoring mymacos from time machine backup also failed. At this point I have a slight preference for replacing the SSD for a definitive fix.

I would not rule out that the coffee has caused more damage than just to the SSD.

 

[emteek]

I would not rule out that the coffee has caused more damage than just to the SSD.

Ok. So a SSD replacement is not a guaranteed fix. Coffee came in through the cooling vents into the right rear near the SSD. Was a miniscule amount but killed whatever it touched seemingly. Its still my favorite beverage.

 

[chrfr]

Ok. So a SSD replacement is not a guaranteed fix. Coffee came in through the cooling vents into the right rear near the SSD. Was a miniscule amount but killed whatever it touched seemingly. Its still my favorite beverage.

Coffee can be very destructive, especially so if it has dairy and/or sugar in it. Have you run any diagnostics on the Mac? I can't remember if it's built into the 2013 model, but try starting up while holding the d key, or option-d.

 

[emteek]

Strictly coffee with cream, no sugar ions for added conductivity. Hadn't tried diagnostics. Looks like Apple diagnostics is built into macs from June 2013. Holding the d key runs native diagnostics and gets me a message "there may be an issue with a storage device" and reference code VDH002. Then it offers to boot in macOS recovery for support and service options.

 

[emteek]

support and service options seems hung on this page. Kind of moot though. Not really looking for service haha.
file:///System/Installation/CDIS/macOS%20Utilities.app/Contents/Resources/en.lproj/AppleDiagnostics.html?serialno=xxxxxxxxxxxx&refcodes=VDH002&language=en&version=1.0.45v1