Was the computer running? There's quite a few different variables here, so it's hard to say which is at fault. The charger is limited to 1.5A, so the voltage will drop if the computer draws more than this. This is normal as the Portable is not designed to run off charger alone. It's possible the charger is bad as well and can't even provide that much current.
I've noticed the backlit Portable's display is much harder to see with the backlight off compared to the non-backlit version. Likely just the difference in screen reflectivity due to the addition of the backlight.
I set the bench power supply to 6.7V and the system, using the floppy disk, booted fine. It was this setup for which I took the pic. I also checked the battery level in the CP and it read full at this level. Adjusting it down to about 6.2V and the battery level in the CP showed a corresponding decrease in "charge".
I measured the battery terminals, unloaded, and they measured 6.26V.
With the battery out and the Portable power supply plugged in I measured the battery compartment "fingers" and read 5.22V.
Is the 5.22V read at the "fingers" the voltage I would expect to see in a properly functioning charge circuit?
I picked up an inexpensive bench power supply, set it for 6.7 volts and powered on the system. Unfortunately it appears the hard drive no longer functions so I am unable to boot it from there. My only option is the floppy which works fine but does not power on the backlight. I will have to work on obtaining a copy of the brightness control panel and somehow get it on the floppy. Or just wait until I stop by my friends place and pick up a copy there.
Can anyone confirm the 5.22V I measured at the battery compartment "fingers" is correct? If not is it too low? Too high?
