Help! noob in over his head with new ("used") Tenlog TL-D3-pro setup :-(

[minneapolis-matt]

The general shape of the EE-SX6 is consistent with an IR detection module. Consider to move the extruder assembly as far away as possible, then power up. As the mechanism begins to move, insert a piece of plastic or paper into the slot to trip the sensor.

The statement that there's nothing in the area to move into the slot is fairly useful in this discussion. If the tripping causes the carriage to zero, you know there should be something to move into the slot.

Thank you!

It seems that I spoke too soon.

The small black tab barely visible on the lower outside of the extruder in the second picture now triggers the e2 limit switch on the right when homing by moving directly into the indicated slot.

Nothing seems to be able to get the e1 limit switch on the left to trigger however. is it safe to assume a high chance of successful repair simply by replacing the limit switch on that side?

I found the optical limit switch on the tenlog web site and ordered 2 of them for a total of $17 with shipping.

[fred_dot_u]

The switches from one side to the other should be identical. You should be able to swap them to see if the problem follows the switch. If it does, replace the switch. If it stays on the original side, replace the entire printer. Oops. I mean there may be a mainboard problem.

[minneapolis-matt]

The switches from one side to the other should be identical. You should be able to swap them to see if the problem follows the switch. If it does, replace the switch. If it stays on the original side, replace the entire printer. Oops. I mean there may be a mainboard problem.

Ok, when homing, the printer seems to always position the right (E2) side before the left side. Help me see if I understand the implications of this correctly. This means that even if I find that I can't get the sensor that I removed from the currently non-working left side to work on the currently working right side (a relief since the "bad" left side sensor working fine on the "good" right side says bad mainboard) I'm not going to readily be able to directly test that the currently working right side sensor will function plugged into the left side because if the right side doesn't properly home first I need to power it off. it seems clear the collision is not good for the printer and I certainly don't need to invite more damage. Similarly, I'm not sure I can verify the functionality of the Z-axis sensors or the y axis limit switch because it looks like those homing movements only occur after the X-axis homing.

So, if I verify that the left side X-axis sensor doesn't seem to work, what else might I be able to do while I wait for my E1 extruder and my optical sensors to arrive on a slow boat from China to try to look for show-stopping issues or pre-emptively replace parts on this thing? Nothing I can safely do to check the other homing movements?

Basically when these parts finally get here, I don't think I am going to have much 30 day return time left to order and wait for any further parts so I think if I can troubleshoot any other parts even before they get here I had better do so. but of course, I m a nearly clueless 3d printer noob. Is there anything I should do with the heated bed? Some kind of inspection of the nozzle? Anything

Thank you again for all of the help!