OMTech Laser Power Supply: How to Know It's Failing and What to Do About It

OMTech Laser Power Supply: How to Know It's Failing and What to Do About It

The laser tube gets most of the attention when CO2 laser owners talk about consumables. The power supply is the quieter failure — but in some ways it's the more disruptive one, because it tends to go without warning and its symptoms get misdiagnosed for days before the real cause is identified.

For the fundamentals of how a CO2 laser turns electricity into a cut in the first place, see our guide to how laser engraving works — useful background before diagnosing what's gone wrong.

We've replaced three power supplies on our older OMTech machine. Here's what we've learned.

What the power supply actually does

The laser power supply (often labelled MYJG or LPSF on OMTech machines) converts mains electricity into the high-voltage DC current the laser tube needs to fire. Without it, nothing cuts. It also regulates the power level your controller requests, which is why power supply problems often look like cutting problems.

How to tell it's the power supply and not the tube

This is the question everyone gets wrong first. The symptoms overlap — the machine isn't cutting through, power adjustments aren't helping — and the tube gets blamed because it's the more familiar consumable.

The key difference is in the pattern:

Dying tube: gradual fade. Cuts get weaker over days or weeks. You compensate by increasing power or slowing speed, it works for a while, then stops working again. A pattern of declining performance with temporary recoveries.

Failing power supply: more sudden. The machine is cutting normally one day and the next it isn't cutting through at all — even on materials and settings that worked fine yesterday. Changing power and speed settings makes no meaningful difference. There's no fade, no temporary recovery. It simply stops performing.

If you're experiencing the sudden version — fine yesterday, not fine today, settings changes doing nothing — test the power supply before you order a tube.

How to test it

Before you touch anything, switch the machine off and wait at least a minute. Laser power supplies hold a lethal charge after the machine is powered down. This is not a precaution to skip.

The simplest test: use LightBurn's laser pulse function to fire a brief test shot at low power onto a piece of scrap material. If the tube fires weakly or not at all, and the tube itself is relatively new, the power supply is the likely cause. You can also check whether the power supply's indicator light behaves normally on startup — a supply that's failing sometimes shows abnormal indicator behaviour.

If you have any doubt, contact a competent engineer rather than diagnosing blind. We can recommend a reliable freelance laser engineer if you need one — get in touch.

Where to buy a replacement

The power supply in most OMTech 80W machines is an 80W CO2 laser power supply — sometimes listed as MYJG80W. At around £150 it's relatively affordable as machine parts go.

As with tubes, the OMTech website is the first stop but may show out of stock. Phone the UK warehouse directly before looking elsewhere:

We've also had good results with Cloudray, who make quality compatible supplies and ship quickly to the UK. Their 80W supply is available on Amazon UK — see the Cloudray 80W laser power supply on Amazon. Check the wattage rating matches your machine before ordering, and buy from a seller with a clear return policy in case the replacement unit is faulty — it happens.

Replacing it yourself

A power supply swap is a wiring job, not a mechanical one. The supply sits in the machine's electronics compartment, held by a few screws. The connections are labelled and there aren't many of them — photograph everything before you disconnect anything and reconnect in reverse order.

Safety is not optional here. A laser power supply works at voltages that can kill. Always:

  • Switch the machine off at the wall and unplug it
  • Wait a full minute before touching anything inside the machine
  • Do not touch the large capacitors on the supply board
  • Follow OMTech's YouTube tutorials step by step

If you're not confident with basic electrical work, don't do this yourself. The part costs £150; a repair from a qualified engineer may cost less than you think and is considerably safer than a rushed DIY job on live high-voltage equipment. We can point you toward reliable help — just ask.

Prevention and planning

Power supplies don't have a defined service life the way tubes do, but in hard commercial use — 5 to 10 hours a day, five days a week — ours have lasted roughly 18 months to two years before needing replacement. A hobby user running a few hours a week should expect considerably longer.

The most useful thing you can do is keep a spare to hand once you're running commercially. A dead power supply with no spare in stock means a machine standing idle, orders delayed and an urgent delivery charge on top of the part cost. Buy the spare when the machine is working, not when it isn't.

For the full picture on running costs and reliability across both our machines, read the OMTech reliability post. And if you need to sort a tube at the same time, the UK laser tube buyer's guide covers sourcing, brands and fitting.

Not sure what you need?

Both machines are running at our showroom in Buckley, North Wales. If you haven't bought yet, our OMTech discount code saves you 4% at omtech.uk. And our training course covers maintenance as well as operation — in person or by video call.

Disclosure: Cherry Grove Craft is part of OMTech's official showroom and referral programme. Links to omtech.uk are affiliate links. The Amazon link in this post is also an affiliate link — we earn a small commission if you buy. All recommendations are based on genuine use.

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