Measuring regulator values on H745

Wolfe, Julian ISC277 at CLCILLINOIS.EDU
Tue Jan 10 15:02:42 CST 2006

Okay, I was trying to find out if my H745 is shady, so I busted out the
DVM and put the probes on the blue wire and a ground wire. (blue is
supposed to be -15v) Nothing.  Okay, so just to check my logic, I hooked
the probe to what is supposed to be a +5v line and a ground on the same
connector, and the light on the 7441 regulator goes out.  Nothing on the

The DVM is set to "20" in the "DC volts" area (it's one of those yellow
dial type DVMs)

Deposits work, but exams cause a bus error.  My power supply isn't shot
in all areas, so how am I measuring this wrong?  I'm measuring at the
power control board, where the backplane connectors are plugged in, and
I'm using the BA11-K manual and prints as a reference for the wire

What am I doing wrong?

More information about the cctalk mailing list