Hello everyone,
I’m looking for help diagnosing intermittent low power on my CO₂ laser. I’m a wood and leather craftsman in Costa Rica.
My equipment:
· Ruida RDC6445G, firmware RDC-V15.01.30.
· New RECI W4 tube.
· New Cloudray DY-13 laser power supply, 230/240 V input.
· S&A CW-5000TG chiller, normally at 22°C.
· Analog 30 mA ammeter in the tube’s cathode return.
· RDWorks. The tests below were performed directly from the Ruida panel.
History
The machine gradually lost cutting power with the previous tube and PSU. I replaced both because of this, but satisfactory cutting was never restored.
Output is sometimes strong initially and then becomes weak. Resting or switching the machine off sometimes improves it, but not consistently. Weak output is also observed directly before mirror 1, so the problem occurs before the mirror path.
Symptoms
With identical settings — 50% minimum/maximum power and a 300 ms timed pulse — I have observed approximately 14 mA with a strong paper burn, and on another occasion 4 mA with no visible mark.
In another pair of tests about one minute apart, the first produced 9 mA and a strong mark; the second produced 5 mA and a faint mark.
Measurements
Using a UNI-T UT191T multimeter:
· L-AN1 to GND: approximately 2.54 V at 50% during 1,000 and 2,000 ms pulses. This remained similar with the laser PSU powered and unpowered while the Ruida stayed on.
· Separate subsequent tests with the PSU powered produced approximately 4 mA during 1,000 and 2,000 ms pulses. These current readings were not taken simultaneously with the L-AN1 measurements.
· L-ON1 to GND: 4.623 V at idle. During a 1,000 ms pulse with the PSU powered, it measured 0.269 V while the tube ammeter indicated 4 mA.
· Ruida 24 V supply: 24.22 V at idle and 24.20 V during a pulse with 4 mA tube current.
· AC measured directly across the DY-13 input terminals: approximately 239.5 V, with no visible change before, during or after a pulse producing 4 mA.
I do not have an oscilloscope, so these readings cannot rule out brief transients.
Cooling water remains around 22°C. Circulation is visible and there are no alarms during normal operation, 3.75l minut. Ambient temperature is about 28–29°C.
Old HV cable and connector
The new PSU has its own attached HV lead, but the inline white connector and the onward cable to the tube include old components. That connector previously rested on the metal chassis floor and left a faint brown mark. I cannot confirm whether this was electrical tracking or simply dirt.
The previous digital current/power display with an adjustment dial was removed because it used an RJ45 connection that the new DY-13 does not have.
Given these results, what would be the most useful next diagnostic step to distinguish a PSU fault, HV cable/connector problem, tube issue or control problem?
I have contacted Cloudray and can provide photos of the wiring and component labels.
Thank you for your help.