rubber_jonnie wrote: Wed Feb 09, 2022 1:52 pm
Is that a crystal/oscillator hanging off the edge of the PCB? Looks a bit ropey!!
Yup, I think it's a factory mod too.
Good news is I resoldered the wire and now have comms with the drive. Bad news is that the spindle motor doesn't run, not sure yet if that's an electronics issue or the motor itself.
rubber_jonnie wrote: Wed Feb 09, 2022 1:52 pm
Is that a crystal/oscillator hanging off the edge of the PCB? Looks a bit ropey!!
Yup, I think it's a factory mod too.
Good news is I resoldered the wire and now have comms with the drive. Bad news is that the spindle motor doesn't run, not sure yet if that's an electronics issue or the motor itself.
Sounds like progress to me
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Been having a bit of a scope on the drive, the motor board (this is a direct drive motor) is getting +12v & +5v. I can also see that the motor activation line is getting driven high by the VIA chip when any activity is required, but the motor does not spin up.
A quick eyeball doesn't show anything obvious, but I'm going to check all the caps, diodes, resistors etc next. Fingers crossed it's not a motor winding - I'll figure out how to continuity check those later.
PXL_20220209_162716934.jpg (350.17 KiB) Viewed 2631 times
BennehBoy wrote: Wed Feb 09, 2022 4:31 pm
Been having a bit of a scope on the drive, the motor board (this is a direct drive motor) is getting +12v & +5v. I can also see that the motor activation line is getting driven high by the VIA chip when any activity is required, but the motor does not spin up.
A quick eyeball doesn't show anything obvious, but I'm going to check all the caps, diodes, resistors etc next. Fingers crossed it's not a motor winding - I'll figure out how to continuity check those later.
PXL_20220209_162716934.jpg
I assume the whole shebang is run by that controller IC, could be something to do with that. Do you have a working one you could probe?
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Afraid I don't have a spare to test, and yes I guess it is controlled by that IC. None of the passive stuff seems b0rked, and the motor coils have continuity. Without any schematic I'm a bit at a loss tbh.
BennehBoy wrote: Wed Feb 09, 2022 6:08 pm
Afraid I don't have a spare to test, and yes I guess it is controlled by that IC. None of the passive stuff seems b0rked, and the motor coils have continuity. Without any schematic I'm a bit at a loss tbh.
Bugger then!!
I know the feeling with my Seltron Apple ][ drive. Zero info or schematics, so I'm winging it!!
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Pin 2 seems to be what should initiate the motor starting or stopping, low=start, high=stop. So an inversion of what's coming from the CIA control line, tracing that line it looks to run through a transistor of some sort, and I never see the line be anything other than low at the motor IC (which you'd think would mean it would spin constantly?). I'll see if I can pull that transistor and test it.
Pin 2 seems to be what should initiate the motor starting or stopping, low=start, high=stop. So an inversion of what's coming from the CIA control line, tracing that line it looks to run through a transistor of some sort, and I never see the line be anything other than low at the motor IC (which you'd think would mean it would spin constantly?). I'll see if I can pull that transistor and test it.
Sounds like that transistor is a reasonable suspect right now.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
