501 0D error, and My macbook pro sudennly super slow.

What do mean by the AHT "and got the 501 0D error."? That is not an error code that I am familiar with the AHT.

Have you recently installed new hardware or software?

Check these two troubleshooting articles:

https://discussions.apple.com/docs/DOC-3521

https://discussions.apple.com/docs/DOC-3353

Ciao.

If possible, these steps should be taken while booted in “normal” mode, not in safe mode. If you’re now running in safe mode, reboot as usual before continuing. If you can only boot in safe mode, you can still use this procedure, but not all of it will work. Be sure to mention that in your reply, if you haven't already done so.

Note: If you have more than one user account, Step 2 must be taken as an administrator. Ordinarily that would be the user created automatically when you booted the system for the first time. Step 1 should be taken as the user who has the problem, if different. Most personal Macs have only one user, and in that case this paragraph doesn’t apply.

Triple-click anywhere in the line of text below on this page to select it:

PB=/usr/libexec/PlistBuddy; PR () { [[ "$o" ]] && printf '\n%s:\n%s\n' "$1" "$o"; }; PF () { o=$($PB -c Print "$2" | awk -F'= ' \/$3'/{print $2}'); PR "$1"; }; { o=$(kextstat -kl | grep -v com\\.apple | cut -c53- | cut -d\< -f1); PR "Loaded extrinsic kernel extensions"; o=$(launchctl list | sed 1d | awk '!/0x|com\.apple|org\.(x|openbsd)|\.[0-9]+$/{print $3}'); PR "Loaded extrinsic user agents"; o=$(launchctl getenv DYLD_INSERT_LIBRARIES); PR "Inserted libraries"; o=$(crontab -l); PR "User cron tasks"; o=$(cat /e*/lau*); PR "Global launchd configuration"; o=$(cat ~/.lau*); PR "Per-user launchd configuration"; PF "Global login items" /L*/P*/loginw* Path; PF "Per-user login items" L*/P*/*loginit* Name; PF "Safari extensions" L*/Saf*/*/E*.plist Bundle | sed 's/\..*$//;s/-[1-9]$//'; o=$(find ~ $TMPDIR.. \( -flags +sappnd,schg,uappnd,uchg -o ! -user $UID -o ! -perm -600 \) | wc -l); [[ $o -eq 0 ]] || printf "\nRestricted user files: %s\n" $o; cd; o=$(find -L /S*/L*/E* {,/}L*/{A*d,Compon,Ex,In,Keyb,Mail/Bu,P*P,Qu,Scripti,Servi,Spo}* -type d -name Contents -prune | while read d; do ID=$($PB -c 'Print :CFBundleIdentifier' "$d/Info.plist"); ID=${ID:-No bundle ID}; egrep -qv "^com\.apple\.[^x]|Accusys|ArcMSR|ATTO|HDPro|HighPoint|driver\.stex|hp-fax|JMicron|microsoft\.MDI|print|SoftRAID" <<< $ID && printf '%s (%s)\n' "${d%/Contents}" "$ID"; done); PR "Extrinsic loadable bundles"; o=$(find /u*/{,*/}lib -type f -exec sh -c 'file -b "$1" | grep -qw shared && ! codesign -v "$1"' {} {} \; -print); PR "Unsigned shared libraries"; for d in {,/}L*/{La,Priv,Sta}* L*/Fonts; do o=$(ls -A "$d"); PR "$d"; done; } 2> /dev/null | pbcopy; echo $'\nStep 1 done'

Remember that you must be logged in as an administrator for this step. Do as in Step 1 with this line:

PR () { [[ "$o" ]] && printf '\n%s:\n%s\n' "$1" "$o"; }; { o=$(sudo launchctl list | sed 1d | awk '!/0x|com\.(apple|openssh|vix\.cron)|org\.(amav|apac|calendarse|cups|dove|isc|ntp|post[fg]|x)/{print $3}'); PR "Loaded extrinsic daemons"; o=$(sudo defaults read com.apple.loginwindow LoginHook); PR "Login hook"; o=$(sudo crontab -l); PR "Root cron tasks"; o=$(syslog -k Sender kernel -k Message CReq 'GPU |hfs: Ru|I/O e|find tok|n Cause: -|NVDA\(|pagin|timed? ?o' | tail | awk '/:/{$4=""; print}'); PR "Log check"; } 2> /dev/null | pbcopy; echo $'\nStep 2 done'

You can then quit Terminal.

Note: If you don’t have a login password, set one before taking Step 2. If that’s not possible, skip the step.

Remember, Steps 1 and 2 are all copy-and-paste — type only your password. Also remember to post the output.

This doesn't look like a software issue.

Make a "Genius" appointment at an Apple Store, or go to another authorized service provider.

Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional — ask if you need guidance.

If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.

Keeping your confidential data secure during hardware repair

*An SSD doesn't need to be zeroed.

Hi insarjuss!

I also have a mid 2012 MacBook Pro with the same issues that you describe. Did you manage to solve the problem that you had with yours? If so, how did you do? Would appreciate any advice over here.