Root password for fresh 5.1 install on 43p-140?

I've installed AIX 5.1 on a 43p-140, but am unable to log in. At no point in the install did it ask me for a root password. When it boots to the console prompt, I enter "root" as a username, and then after 1 second it cycles right back to another root prompt.

I am accessing the 43p-140 workstation via Minicom under Linux connected via a serial cable.

How do I set the root password?

Thank you kindly for your responses.

After install there is no root password, after (root) login you will be prompted to set the password.
I have seen this problem before with a few terminal setups.
Try a different console / serial cable / terminal emulator.
9600, 8, n, 1, hardware hand shake / Xon/Xoff
The serial cable needs to be both software and hardware wired, I'll go look for the pinouts.

Can't do a pretty picture of the cable pinouts so here goes in text for a DB9 to DB9 cable:
3 - 2
2 - 3
7 - 8
8 - 7
4 - 6 and 1
6 and 1 - 4
5- 5
9 - 9

I've had a lot of experience with AIX consoles and nothing else will work for all the senarios, i.e. service processor menu, SMS, AIX, diagnostic boot, diagnostic CD boot.

Even if your cable is correct you can still have problems with various terminals / terminal emulators.

Win2k hyperterm had a similar problem, as far as I know there is no fix, so your terminal emulator may have the same problem.
Try another (few more) emulators.

was it an mksysb nim or tape install? if so, then the root password may be set from the machine the mksysb was made from

Thank you Duke - I have examined my cable and see that cable pinouts are my issue. I will see about getting a proper cable.

Thank you,
Akbar.