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Taylor Finley
12-09-2014, 5:43 PM
Hello,


I have a shenhui 350 machine. Last week the laser's etching power decreased substantially. I noticed a squealing buzzing sound and saw the plasma in the tube was dancing around on the high-voltage supply side, opposite the side where the light exits the tube. The tube was the original from the factory, and had about 250 hours on it near 95% power, so I thought it had seen its useful life and ordered a new tube.


New tube gets here, same problem--can't etch through a thin layer of paint, just leaves burnt paint. I've re-done the alignment a hundred times now. The problem seems electrical.


When I fire the laser by pressing 'test' on the power supply, I get a steady beam. When the rdcl320-a controller fires either a pulse or continuously, there is a buzzing crackling noise and the laser puts out very little energy.


I switched over to the second laser output on the controller board and fired some tests that way. For about 10 minutes it seemed to work fine, except when vector cutting I noticed when the y axis was moving laser power was decreased, and then the buzzing and crackling returned for all modes (except power supply test button).


I am at a loss here... I don't know what component to replace, or where else this problem could be coming from. Is there anything simple I'm overlooking? I've removed and re-set all the wire connections. I've checked the continuity to ground on every grounding point.


I have so many orders piled up and am running out of time and money to throw at this machine, can anyone here help??


Thank you!

Dave Sheldrake
12-09-2014, 6:18 PM
Check the HT (High voltage) side of the wire (the fat red wire) it could well be leaking to earth resulting in both buzzing and loss of power

cheers

Dave

William Dillon
12-23-2014, 11:42 PM
Was there a follow up to this? My laser came from the factory making that noise, and its my first machine, so I thought it was normal. I couldn't increase the power above 4 mA, any more and the laser (or power supply) would cut out.

Then, yesterday, I was cutting and the noise stopped. Power went down a bit, but now I could use the potentiometer to increase current to 6 mA, and I have more power than ever.

I'm of course interested in whether I was arcing, but I guess now I won't know now. This is something that I'm going to be thinking about for some time without some closure