> One is for the solenoid that lowers the pad onto the disk to allow > reads/writes. > > One is for the sensor to detect track 1 (LED and detector) > > One is for the sensor to detect sector pulse > > One is for the servo motor that moves the head in and out > > One is for the read/write head > > One is for the 110v power to the drive motor itself that spins the belt > and the disk via the center spindle. > > I did not move the 110v power wire because that is from a common harness > between the drives and it's pretty obvious the disk is spinning. :-) The > other five were switched between controller channel 0 and 1 (PD0: and PD1:) > > At this point I think I'm onto the sector pulse LED not working due to > 5v being applied to it. Will be working on that more this morning with a > better/more precise power supply.
Jumping in at this point... In a 'real' RX01, each sensor LED (track 0 and index) has the cathode grounded and the anode connected to +5V via a 68ohm series resistor. If you measure the voltage across the pins with the LED disconnected (or if the LED is open-circuit) with any reasonable meter, it'll read 5V. The meter will not draw enough current for the resistor to drop a noticeable voltage. Of course there is no reason why the resistor couldn't be between the cathode and ground (with the anode connected to +5V). It's a simple series circuit, the current is the same everywhere. The thing that puzzles me is why you read 5V across an LED that seems to work on the bench. I wonder if a connection is open somewhere. -tony
