Mitsubishi uses different combinations to get into TV service mode, depending on the TV. I have two Mitsu TVs and can only get into one of them -- the other one (a Mitsu CS-2724R, Aug 1990) remains a mystery.
Try any of these.
MENU 1 2 5 7 service menu (WS-xxx05 2000 models) MENU 1 2 5 9 convergence / geometry MENU 1 2 7 0 scary menu (2000 models -- set HDTV input port; master resets, etc) MENU 1 3 7 0 scary menu (1999 models, i.e. xxx03) MENU 2 3 5 6 TV Guide Plus diagnostic MENU 2 3 5 7 service menu -- older Mitsu sets, including xxx03 1999 models MENU 2 3 5 8 features menu MENU 2 3 5 9 convergence / geometry MENU 2 5 7 8 MENU 8 2 5 7 service menu (WS-xxx07 2001 models) MENU 8 2 5 8 features menu MENU 8 2 5 9 convergence / geometry
If you find other combinations, or want to report which codes work for your set, let me know and I'll add them here.
Reminder that while some of these codes may help you get into service mode, the main Mitsubishi TV Service Modes page may not apply to your TV. Two others that I know of are service menus for the CT21AM2(A) and the xxxx7 (2001 models).