Laser begins firing on startup after C3D install

Lasers
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142

Thank you for finding some. I was specifically looking for the lite-on brand, must be why I missed seeing those.

I am going to try measuring the resistance again and will report the results.

143

Ok, remember I don’t know the quality of what comes from Amazon.

It looks like the 817 may work, hard for me to tell without knowing how the photodiode is being driven.

144

When I place negative lead on G positive lead on laser fire I get ~17ohms resistance.

I measured in the following ways (negative lead always on G and positive lead always on laser fire):

Laser ground stud to opto laser fire: 17ohms
Laser fire stud to opto ground: 17 ohms

Helpful?

145

So I’ve been watching this thread the past few days and it’s amazing the dedication I see with Don and Doug helping you through this going into such minute detail. My hat is off to you guys. One thing though, is the board new, and if so, I would press Cohesion to supply you a new one. Especially after the depth of troubleshooting you guys have gone through. If they were to give you any flak, I would link this thread to them.

146

Yes, water pump and K40 are plugged into an outlet with nothing else connected to it.

LaserBoard supply is a 2 prong.

LaserBoard supply currently plugged into the GFI and has not tripped since that one and only time.

147

Basically it reads 17 ohms no matter which way you connect the meters leads right?

148

I agree. I have been absolutely astounded by the dedication on Don and Doug, especially Don! The fact that you go to such lengths to help a stranger on the internet is so greatly appreciated.

Seriously @donkjr and @dougl thank you.

And yes I agree that C3D needs to step in to provide SOME level of support. There is no way to get in contact with them and they direct all support needs over to the forums, which at this point in time, seem to be ignored. Very frustrating.

149

No, if I switch them and have positive lead on G and negative on laser fire my meter reads “1” - so no continuity

150

I don’t have a C3D board but wondering if it possible to trace back the 2 circuits to see if the Fire LED is driven by the same processor pin as the Fire Optocouple.

if the circuits are tied then I would start troubleshooting back to the processor pin to the Fire LED circuit to see if held high or low on power up and then send a M3 S1.0 command via the LightBurn console to see if the LED turns on and/or the pin voltage changes.

If it’s the optocoupler transistor/output failing, then we should still see the optocouple LED drive side changing state and being in the proper state on power up.

If the startup state of the drive circuit is not right then the output pin on the LPC1768 could have failed or for some reason the firmware code not right.

151

I generally agree. However, an argument can be made (the GFI event) that something blew the opto not that it was defective at manufacture.

I have known Ray for a long time and he provides good support. I am guessing they are struggling for some reason over at C3D as its unusually quiet.

My approach is to keep plugging at a problem machine until help arrives…:slight_smile:

152

Unfortunately we have no way to truly confirm this either as I did not have material in the bed right after putting the board in and heard the hissing sound. So it’s anyone’s guess as to what was truly happening right out of the gate.

153

@dougl do you think it would be worth trying to run a job and see if we even get the red fire LED? In the other thread Ray had him check for that first and run some commands, then once he confirmed he had the fire LED moved on.

Could help go down the path you mentioned?

154

That said any additional information is useful when we are looking for clues…

155

Whoa … whoops have to noodle this change in info.

156

I just powered on the machine and pressed test fire. Since the issue with the C3D happens when not even plugged into power or the computer, I did not see a need to press the Nano further and try to run a job…

Changing the PWM from 200 to 400 in the config file did not make a difference.

157

If it come on it will confirm that the Led is wired like we expect and we can believe that the processor is not holding laserfire on.

If it does not come on then … my head will hurt even more that it is … :crazy_face:

158

And I should do this test under the following conditions, correct?

  • K40 NOT powered on
  • C3D plugged into supplied power supply
  • C3D wired to X and Y and endstop ribbon cable
  • LV connector plugged into LPS and C3D?
159

Okay here’s a test I just ran. Conditions were as follows:

  • K40 NOT powered on (I subsequently performed these same tests with the K40 on and got the same results and measurements)
  • C3D powered on by supplied power supply
  • LV connector NOT plugged into C3D board

Ran command in Lightburn: G1 X10 S0.6 F600

Results: Red LED fire status lights up

I then drew a simple square and ran the job under the same conditions as above. Red LED laser fire status lights up and the laser moves.

I am able to send to home, engage (lock the gantry), and disengage (unlocks the gantry).

I then used my meter to measure on the pins G and Laserfire on the C3D board when running the above command and got the following results:

~15 ohms between G and Laserfire pins at resting state. Nothing powered on, no job running, no commands sent.

Goes down to 2.5 then back up to ~15 ohms between G and Laserfire pins when running the above command. Again, K40 was off, C3D board powered on, LV connector not plugged into C3D

160

I would leave everything as normal but the LV cable.

  • K40 powered on
  • C3D plugged into supplied power supply
  • C3D wired to X and Y and endstop ribbon cable
  • LV connector unplugged from LPS and C3D? (so the laser does not fire while you are setting it up and running job)

Note: that the led may only flash as the command is being executed.

161

Got it, let me run that test again, this time with the K40 on.