|Re: 9114A woes|
Message #2 Posted by Tony Duell on 9 May 2007, 6:01 a.m.,
in response to message #1 by PeterP
Firstly, the battery must be good for the 9114A to pass the self-test. During the self test, the unit spins the disk and moves the head about (which are the operations that take the most power from the battery, of course), so if the battery is bad, it'll not manage to do that. The charger will NOT be enough on its own.
You can get my schematics for the 9114A from the Australian site. I would start by looking at pages 1 and 2 of the controller PCB schematic, which are the PSU section. There are 3 power rails in a 9114A -- Vc, which is 5V all the time the unit is switched on (it powers the RAM chip, etc), +5V, which powers the rest of the logic and which is turned off when the unit goes into powersave mode, and +12V, which is only turned on to the drive power connector when the unit needs to operate the disk drive motors.
Check the output of the battery pack when the unit is turned on and performing the self-test. A convenient way to do this is to connect the -ve side of your meter to the drive chassis (this is connected to the unit's ground rail) and the +ve side to one of the wires on the back of the power switch. You should get 6V here, it should not drop during the test.
Then measure Vc on TP8. Then check 5V on TP10 (this should be present during the self-test). And finally check the +12V line on TP9 (TP11 is the common ground connection for the -ve side of your voltmeter).
If all that checks out, then I think you're going to have to get into the controller board logic circuitry. Do you have a logic probe, logic analyser or oscilloscope?