Hello. In my Experience, Inspection mode (if in Control panel, and car top swiches 'Insp/Norm' Set as Norm, but active inspection mode (on SPBC or TCBC, OR GECB pcb Led 'Ins' Active') perhaps can be if RS-14 on J-BOX (from car top) adr 19 was a badly (bad pcb RS-14 adr 19). Adr 19 used for inspection on car top. I have some elevators Otis, and that i caught on OTIS Gen2 controller MCS 220 RX2 with SPBC III & GECB, perhaps similar trouble on MCS 220 C, MCS 220, MCS 220 CX and etc. Check the Schemes, if that same as i say, check it. You can do the 'self-test' (with Service tool if you have it), but that not best way. Rsl line after test may show you wrong device. Best way, (if you doesn't have svt), that: swap the RS14 with other (19 adr, and 18). What it give you? If Rs for 19 adr (inspection) bad, and you swap it on 18 adr, you see that a Door inv can off or something be wrong in work door. Adr 18 used for Doors (Door inv, DCSS, Photocell, and ST1,ST2,ST3 Commands (inputs)). Best regards.