Denford Software & Machines

Hi. The machine has power but the 7 segment LED doesn't light up at all during or after powering up. It seems there is no power going to the board.

I've had the machine a long time and can work around most issues but don't even know where to begin with this one. I think the fuses are okay but at a total loss.

Please help!

Can you check the Next-Step logic voltage on TB 11 pins 4 & 5. You should have 24 Volts AC as in drawing RC-1C.

Hi Martin. Thanks for getting back to me so quickly. I have no background in electronics so please bear with me!

I found TB11 and the 24v pins, attached a multimeter and got a resistance reading of 168.6 (see pic)

I have not got a clue if I'm reading it correctly or if it's good or bad. I'm hoping you might walk me through it in baby steps. Many thanks in advance.

Martin asked you to check the voltage on those pins not the resistance. turn the dial on your meter to 200v~.
It isn't wise to connect a meter on the resistance setting to a powered circuit.

Pete

Thanks Pete. You're right. I was sure to isolate the machine.

I've rechecked and, with the meter set at 200v~, I get no reading. Zero, zip, Nada, 0.0.

What's my next move? I really hope the board isn't finished. They've stopped making them haven't they?

Thanks again,
Pete

Hi Pete,

It could be as simple as the low voltage light pulling down the 24 volts .

If not check you have 240 volts ac going in to the transformer, Violet & Grey wires.

If that is ok remove fuse F3 & check the output for 24 volts ac.

All fixed!

Turns out one of the 6.3amp 20mm fuses was blowing due to the Z brake.

Disconnected the brake diode on terminal 15, replaced the fuses and got power back to the board.

This locked the Z brake on so cut the wires to it, removed the outer casing and removed the Z brake altogether.

She's now running like a virgin on prom night.

Massive thanks to Martin who talked me through the whole thing. Where would we be without him? All hail to our cnc overlord!