The HDD WILL NOT allow the mod chip to work. In japan, this is an issue to this day. To boot backups you'll have to make sure the HDD doesn't get power. Also if you even try to boot an backup with the HDD on it will corrupt Navigator in japan so take heed.
JAP 60GB PS3 (release date)
37000 L V7 Ocean Blue Matrix Infinity BB Navi (.32)
30001-R V4R Magic ICE 91f3+ PS2 Linux (2.4.1)
10000 V0 No Mod, PSP-1000 1.0 FW 100K release model
PS2 Linux Kit (BB Navigator Installed)
Scph-5501 Stealth, All Sega Systems
Cube with Save, Xbox 1.0 Modded