If both of your consoles are from the same region (last two digits in SCPH-Productcode), I assume it is his PS2 or something is wrong with the MC/Install.
About the sound&looping.
I guess, you have a CRT-TV and it makes some noise, when it switches the V-Mode.
It seems it recognizes the MC and itīs uptate, but hangs on decrypting the KELF/osdmain.elf and then restarts the PS2-Browser (which lead into a loop, if you do not un-plug the MC).
That could be due to different reasons.
-your ps2 is not the same MG-Region as the other one (but still, it uses the same OSD-Update-Folder).
-your dummies have not been properly patched, so for example you have the un-patched dummy on MC, the OSD tries to load it as update and fails there...
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux