That is what I expected…
This may be futile but can you take some close-up photos’ of the C3D board in the area of the laserfire.
I am looking to see if I can find out how an optocoupler is wired to the laserfire. The optocouple should be a four-legged chip like an 817.
@Dkwells try this:
Plug the L pin back in on both ends of the LV connector.
You will still have a gnd and L connection in that connector between the LPS and the C3D.
Unplug the wire to the K+ connector (it comes from the control panel).
Turn on power … does laser fire???
So you want:
-
LV connected to C3D and LPS
-
L and G connected to both ends
-
24v and 5v not connected to C3D
-
K+ not plugged in
Correct?
So you want:
- LV connected to C3D and LPS THIS IS THE CABLE RIGHT?
- L and G connected to both ends
- 24v and 5v not connected to C3D
- K+ not plugged in
Correct?
[/quote]
Yup!
Yes, laser fires at power on with those conditions met.
Chip # L217 E13
That’s the opto.
Will trace it out when I get home.
This one. I cut 24V and ground wires(both were blue also) then realized I needed GND from there and soldered the black wire which goes to a gnd pin on the controller board. Blue 5V and L are still connected but I only connect my controller to L.
The FETS on the controller pulls to ground so I too was surprised to see 22.6V on L and expected 5V since I thought I remembered seeing that section of the schematic from when my 10K POT was causing jumping power levels and had to go to a 1K POT.
On the problem system, we saw 5V on L(on the LPS) with nothing connected so we can figure it is as the schematic shows, ie 5V pullup through a resistor on the Anode(+) of the LED of the photo diode so the C3D should not have a pullup enabled on the laser PWM output. If it does, it would be pulling up to 3.3V so it will be applying 3.3V to the Cathode(-) of the LED in the photodiode and possibly biasing it enough to emit.
The C3D laser output pin should be high impedance(no pullup and no pull down) so that way L will float when not being driven and pulled to ground if the pin drive setting is correct(active Low). The M2Nano can be pulled up since it is a 5V device…
Here is what I came up with as my best guesses from photos
See if you agree???
Pretty much what I expected …
We need to verify that A [laserfire] is not connected to anything else like a resistor and then to a power supply somewhere.
There is a through hole that looks like it might go to the other side of the board just above the Laserfire land.
I cannot see anything on the other side as the connector is on top of it.
Try taking an ohm meter and see if there is continuity between the Laserfire pin and any other component.
Edit: added data sheet
boy it should be working… open collector of a photo diode pulling down the L signal on the LPS should do the trick. But why was 3.x volts on it previously and then 5V when L is disconnected from C3D?
optocoupler not turning on all the way?
You two are certainly more qualified to break down that drawing, I’d be guessing if I tried to add any insight.
I did test for continuity between laser fire and anything else on the board, didn’t find anything.
There is continuity between the 2 red circles and also between the 2 yellow circles. Laser fire and ground. There is resistance between the laser fire pin and ground on the opto - not sure if that is helpful or not. ~17 ohms
Where’s Ray with that schematic, eh?
Acts like the opto is partially on?
that transistor in the photo diode should not have 1.3V across it when at any time. But Dylan measured 3.? volts on L when the C3D was connected to the LPS. I wouldn’t think it would never be at that voltage.
I made a post in the hardware section as well as the software section of the cohesion3d forums in addition to filling out a ticket on their website. If I hear anything I’ll update here.
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Not sure if it’s worth doing all of this given that the laser fires at power on regardless if the c3d board is even powered on or connected to the computer BUT figured I would get your opinions as well.