It seems that you are right, I start successfully the Memorex 102 with
the PSU without flickering, this HDD uses the same voltages as the
Mitsubishi M2894-63D 8" disk drive (24VDC - 5VDC).
It remains me to find out which components are faulty
http://www.zeltrax.com/classiccmp_forum/uts40/M2894-63_board01.jpg
http://www.zeltrax.com/classiccmp_forum/uts40/M2894-63_board02.jpg
I did not know this type of case for capacitors
http://www.zeltrax.com/classiccmp_forum/uts40/M2894-63_board03.jpg
On 12/08/2017 14:30, Dominique Carlier via cctalk wrote:
Note that this produces the same result with either of the two disk
drive connected however your suggestion is interesting.
These two drives have the same age and some capacitors may become
faulty simultaneously. I will analyze the hypothesis, thanks!
I have an old hard drive (MEMOREX 102) with the same connector for the
supply, i'm going to test the PSU with this other device.
On 11/08/2017 16:13, Al Kossow via cctalk wrote:
On 8/11/17 5:40 AM, Dominique Carlier via cctalk wrote:
I continued my investigations about the power supply if the 8406 subsystem.
Here is what I observe:
With the PSU in charge, I mean with a disk drive connected but without the +24V
:
+5V -5V +12V -12V: OK
If I connect the +24V to the drive this is at this moment than the power supply
goes mad and sends erratic alternating
voltages to the + & - 5V and + & - 12v.
It sounds like something is wrong with the disk drives, probably a shorted
capacitor on the drive.
If you apply a resistive load on the 24v does the supply still go crazy?
