No Power to Control Board
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!
CNC Guru
CNC Guru
Re: No Power to Control Board
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.
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Re: No Power to Control Board
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.
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CNC Guru
CNC Guru
Re: No Power to Control Board
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
Re: No Power to Control Board
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
CNC Guru
CNC Guru
Re: No Power to Control Board
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.
Re: No Power to Control Board
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!
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