Centroid Community CNC Support Forum

Hi all,
I got an old Atrump mill with an Elrod M15 conversion. I've been cleaning up and going through the machine thoroughly, and one of the problems that I see is no backlight on the screen. I guess I should have wiggled the connectors while the cover was off, so I'll take it back off and do that. If it still doesn't work, do I need to call Centroid to get a replacement or is there a better route to fixing it?
The tag reads:
PRODUCT: CONTROL CONSOLE
MODEL NO. M15-10
SERIAL NO. 4818 Another thing that I noticed before removing the servos, is that they are very noisy when sitting still, and even noisier when moving. The DC servos on my mill with the CNC7 controller were very smooth and quiet. I'm wondering if these are tuned hotter than necessary, but haven't looked into that yet. Bearings on one motor are bad and being replaced, but that's not the noise.

Thanks for any input.

Kevin

Verify that you have high-voltage AC coming out of the backlight inverter (from white wire to gray wire).

I don't recall the correct value, but it is over 100VAC (maybe 195 or so? maybe higher?). Be careful with your test leads.

If you are getting a suitable AC voltage out of the backlight inverter, but no backlight, then you need a new fluorescent tube. If you are not getting a suitable voltage out of the inverter, you need a new inverter.

For backlight tube replacement, see also http://www.cncsnw.com/M400LCDBacklight.htm

You may be able to test for needing a new backlight bulb by putting a light on the screen.
With a light on it, if you can see the screen it is likely a bad backlight bulb.
If you do need a new backlight bulb we have some in stock, item # 2743.

Okay thanks. I unplugged the tube and get a spark from either live pin on the inverter when touching just one probe to it. My meter started beeping at me for some reason, like it was warning me that I was about the short out the inverter if I tried to touch two pins...I can try again if necessary.

I guess it works a little, because the screen is completely black when it's unplugged. The picture shows it plugged in.

Should I try to get a voltage measurement, or can i assume it's the bulb? Where would I get a replacement for either the bulb or inverter?

CentroidFrog wrote: ↑Mon Aug 11, 2025 3:36 pm You may be able to test for needing a new backlight bulb by putting a light on the screen.
With a light on it, if you can see the screen it is likely a bad backlight bulb.
If you do need a new backlight bulb we have some in stock, item # 2743.

I was replying when you did. I can still see it with a flashlight shining on the screen, if that's what you mean.

Since you have a visible image, and it is just kind of dark, it is likely that the inverter is fine, and just the tube needs to be replaced.

We do have the light tube/backlight bulb in stock.
It's item # 2743 and is $105.
If you'd like to order one please send us an email at support@centroidcnc.com and we'll be happy to get an order setup for you.

Email sent, thanks guys.
Kevin

I got the replacement, but is this the correct part? The old one is in back, and the new one is in front.

I don't want to plug this in and fry it if it's not the correct replacement. If this is the correct part, how is it secured? It's smaller, and I don't see way to secure it or keep it from rotating once inserted.
Thanks,
Kevin,