Power glitch causing my controller to reset

I’ve had this second hand laser for about 2 weeks and I’ve realised there are a few mechanical things that need to be sorted. This is just one of them.

One thing I noticed is that when I use the manual Z adjustment switch on the front panel, or the switch to turn on/off the exhaust fan, sometimes, very intermittently, there is a power glitch.

When this happens, it is indicated by the back-light blinking ever so quickly, and then the controller resets, and the machine goes back to the home position. This is a real pain when setting the focus point manually.

I’ve plugged it into a different power outlets on the other side of the house, but it still happens. I’ve checked that the earth connection is valid - all good. Today I purchased a test plug socket to check for any faults and none were indicated.

So, I spoke to my brother today who is more into electronics than I am, and we came to the conclusion that perhaps it’s a failing capacitor - a “smoothing” capacitor?

This capacitor is at the back of the machine:

I haven’t ran back the wiring to check what it is it’s connected to yet. But it does seem like it’s an important component. There is no bulging or physical damage that I can see.

I guess there is no harm in replacing it just to test. I hope it’s not a power supply issue.

What do you guys think?


Power glitch I’m assuming you mean low voltage? I will have to assume that the back light is some kind of an led strip back there.?

I think you have isolated the problem area with the Z or exhaust fan switch. I’d start my visual/mechanical inspections there.

There are a few options. If it was 100% when you did one of those things I’d say you have some type of mis wire leading to a short. The other option is an open circuit to the supplies, but that seems unlikely.

Since neither of these are the case, it sounds like something that is intermittently ‘shorting’ or lowering of the power supply.

My ‘led’ lights actually go to the mains and not the dc supply as I had thought, so identify if it’s the mains (doubtful) or if they are feed via the low voltage supply. That supply is failing to make the ‘lights’ dim.

These things don’t have the best switches either…

Good luck


I’ve wiggled the switches to see if I can reproduce the issue - but it doesn’t. So I figure that it’s not the switch itself. There are two switches that do the same thing - therefore an unlikely random situation.

Maybe it’s just a loose wire somewhere - shorting - not getting a good connection under load.

This is becoming a “splinter in the back of my mind” situation - slowly and annoyingly pushing itself forward until it’s ultimate end.

If I showed you the condition of the glass laser tube itself - you would be shocked that I’ve managed to produce anything at all.

Stuck mirrors that can’t be adjusted or disassembled, etc. etc. etc… I’ve got it all. !!! :slight_smile:

All good though.

No this is symptoms of the problem and are probably related. I would assume that until proven otherwise. You don’t have another option at this point except what you have stated.

You need to follow the symptoms and see where they lead. Maybe something has a problem in the drag chains where all these wires run and move about…

There is something common, wiring, switches whatever, since these are the only thing that causes it and your only lead to fix it…

I’ve fixed this type of equipment all of my life you have to work with what you got.

You can try isolating each of the ‘switched’ circuits and see if that helps you locate a common problem.

If you run on 110v instead of the EU 220 it could be drawing too much current for the switch itself. Mine were at or over the specified limits when I received it. Fine for 220v mains.

Good luck


Thanks Jack. I’m in Australia so 240v.

The drag chains are not active when this issue occurs. There is no movement in the X/Y axis.

Maybe it is a loose wire somewhere? That’s going to be hard to track down

So no point replacing the Cap?

What is the cap for? I don’t recommend replacing stuff randomly.

Generally these are for something with a motor, like a starting cap, such as ventilation. If it shorts, it usually ‘blows up’ if it opens the motor will start poorly. Neither should cause the issues you report.

Might want to just ‘fiddle’ with the low voltage connections. This kind of operation doesn’t require the lps so it’s pretty safe to stick you paws in the electronics cabinet. Most of the stuff that’s loosing power is probably 24 or 5v…

If you can isolate the supply 24v/5v that may help you identify the culprit, keeping you away from the mains until it’s resolution is more definitive.

It has to be related to the two problems you mentioned. I would think it would have to be an open, if it ‘shorted’ the mains you’d know it.

That’s better, I assume 50 Hz?

Heed the mains, almost 80% of all electrocutions, at least in the US, are from the mains… :crazy_face:


I thought 60Hz in Australia.?

I’m not that clever to isolate and identify this issue, but clever enough to understand there is an issue that i do not understand.

I know there are things I don’t know, I know there are things that are unknown. Known Unknowns? (Rumsfeld, circa late 90’s).

I just want to get on with using this machine, in a purpose that is justified for me having it.

Likely a loose wire somewhere?

Beats me that’s why I asked… Most of EU is 50Hz. Nicolas pick was 220@60Hz.

Good luck.