Definitely looks like Lexicon Day today!!!!!!!! 😁 . After having repaired a PCM70 and an M480L, am I about to fix a third Lex unit in a row?... . So, I really hope this time it's the right one. Unfortunately, as I don't have a Multibus I/IEEE-796 extender board to correctly test the SBC PCB of @nautilustudio 's Lex 224's , I'm left with my own intuition and wild guesses... 🤔 . This 224 was also waiting for a solution to a strange, unpredictable behavior of the (suspected) main CPU board, where it would suddenly blank out the remote head displays and freeze the whole machine... even a cold reset (not to mention a hot one!) would not restart the unit correctly. Had to wait for some time before I could power it back on and resume normal work. . Suspected a fault in the reset circuitry, precisely in this PN2222 NPN transistor on the main CPU card, and whch is responsible for switching the RESET input of the CPU high at start-up then back off after a short while. Since I replaced it, the 224 has been on for hours without a glitch!!! 😊😊😊 . Will leave it on for some more time to see if the problem comes back or not. Just hoping it's not the D8224 CPU timer chip (that's driving the above mentioned transistor's base) that's at fault... 🤞 . #Lexicon #LexiconPro #Model224 #LexiconModel224 #M224 #LexiconM224 #VintageDigitalReverb #DigitalReverberator #M224DigitalReverberator #Fix #Repair #Restoration #VintageElectronics #Nautilustudio #StudioNautilus #StudioPiscineATokyo #PiscineATokyo #TheGoodDoctorPrager