On 5 November 2024 at 06:51 michael27 Said:

Hi

i I have the above lathe which has suddenly stop working.I have change both fuses, and the green/ red on/off button still not working unless you hold the green button in
my guess that the printed circuit board as blown?

As anybody come a cross this before or can suggest where to look next.

Thanks for any help

Hi Michael,

Sounds very much like the NVR / Emergency Stop switch has failed. The board is OK if holding Green down spins the motor.

NVR switches contain a relay and contact that bypasses the Green button which is momentary.

Pressing the green button starts the lathe and bypasses itself by powering on the relay.    The arrangement creates a No Volt Release (NVR), needed to stop the machine mangling the operator by unexpectedly turning back on after a power-cut.  They’re often combined with the RED mushroom emergency off.

Do a search on Amazon for NVR to identify a replacement.  (Other sources available, and Chester may hold it as a spare),  Cost under £10, and they look like:

OR same thing with a RED mushroom Emergency STOP on top:

OR, maybe the Emergency Off is a separate switch, which might be what your DB10 does. (Two red mushrooms!).

The circuit is much the same.   The NVR relay is, I believe, always inside the RED/GREEN button.

Replacing is usually easy because they are wired in with pull off and push on spade connectors – no soldering.  Before replacing check that these connections are in place.  Not unknown for the crimps to fail or a carelessly fitted spade to vibrate loose.

Replace like-with-like a step at a time.  Don’t rip several wires off and expect to remember where they came from!

Hope that makes sense, I’m poorly this morning and am going back to bed.

Another recent thread discussed the same problem in more detail.  Perhaps another kind member will find it for you.

Dave

Check interlock switches on covers, chuck guard etc. There needs to be continuity through all of these before the green button power relay will latch ON.

That is indeed how to check it. Best not to use it like that, though.