Problem with Jensen A540 (turntable) bottom stop bar

[maybelateron]

I have had a Jensen A540 TT from new. It had just under 700 hours on it and is 11 years old. When the bottom trip bar is activated it stops the rollers as it should. When I press the green roller control switch, on either side of the hopper, the rollers will not turn. I have to turn the engine/ignition off, then restart and all is well until the next time it is tripper. Both green roller direction switches work fine (replaced one a few weeks ago), as do the red stop switches.

When the fault occurs there is nothing showing on the control panel to explain it, just the normal data.

Any thoughts/advice?

[Mike Hill]

Check the solenoid with a multimeter, make sure its working. You should have 12v there when it's running and nowt when it's stopped. If you have 12v there after the reset,and it's not turning the rollers the problem is right there. 

 

Then check for continuity in your green reset switch wires.

 

After that I don't know. But is there a separate electric box outside the main speed switch unit?

[maybelateron]

Thanks for the reply. When you say solenoid I am guessing you mean at the hydraulic valve block?

 

I am only aware of one electric box, that being the one on the side of the machine where you start the engine. I will take a look middle of the week when time permits. Thanks again.

[Mike Hill]

37 minutes ago, maybelateron said:

Thanks for the reply. When you say solenoid I am guessing you mean at the hydraulic valve block?

 

I am only aware of one electric box, that being the one on the side of the machine where you start the engine. I will take a look middle of the week when time permits. Thanks again.

Yes that's it.

 

You can take off the little box with the screw through it and check for voltage with the wires removed.

 

Earth it and run 12v to it from battery and you should hear it click open.

 

No click and the coil is not pulling  the plunger open.

 

I have replaced only one solenoid coil in 17 years .

 

There will be another box that holds the circuit board that runs the stress control. There is a way to bypass the reset buttons by bridge wiring on the circuit board or really the contact strip.