Novamill will not connect - limit switch error

[Giles]

Hi, i've had my novamill about 4 years with no issues. Now when i turn the black box on it does not power up the mill (does open lock) and the seven segment display shows the limit switch open error, after about 30 seconds the display also dims to about half the brightness or goes off completely. I then have to wait a minute to turn it back on for the display to fire up at all...any ideas where I should start - i have no idea.

Thanks, Giles

[Steve]

I would start by unplugging all the connectors from the control card other than the power in. Then turn it on. It should load the flash and then sit lit up OK.

If so then start refitting connectors one at a time until you find which is causing the problem

Download the drawings for the machine

NVM-D4K.pdf shows the bottom of the unit and TB11 is the power input. NVM-D3H.pdf shows the top connectors to the card.

viewtopic.php?f=41&t=2628

[Giles]

Thanks for the reply,

So i have unplugged everything apart from the TB11 connector. Still the same. When I turn it on the display show '0' then straight to '.L' then a couple of seconds later it goes blank.

[Steve]

when you say it goes blank do all the LED's and the 7 segment display all go off?

If you plug in connector 10 and monitor the 5V and or the 12V DC and see if that also goes off when the led's do.

The control voltage is created by a regulator on the right hand edge of the card. There are 3 15 pin L298 stepper driver chips next to it.

The Regulator will shutdown if it goes over current or over temperature. I would also look at the regulator and see if its screwed tight to the heatsink.

[Giles]

Yes, the 7-segment display completely turns off. I get 5v between pins 1 and 2 on TB10 which goes off when the display dies. I cant find a 12v between any pins - i assume it should be between 3 and 4. The regulatir looks tight.

[Giles]

On TB10 i get:
5v between pins 1 and 2
4.3v between 3 and 4
-4v between 5 and 6

[Steve]

There must be a fault on the control card dragging down the supply. You may need a new card.
Where are you located?
You could remove the top card with the seven seg display. Power on and monitor the voltage. This would at least identify if the top or bottom is the fault.

[Giles]

Im in Sunbury on thames (near heathrow).

I'll have another look first thing in the morning as to if I can remove the top board.

I guess i need to find someone upgrading or converting to get a second hand board. Or look into the cost if upgrading to v5 - does that replace that board?

[Giles]

With the top board removed I get the 5v still. But I get a drop to +/-0.1v on the others.

[Steve]

It sounds like the top card is the problem though as we have removed most the load from the board it still does not rule out the bottom card having a fault.

The top card can be replaced with a USB card.

The part number is BI00434YY a complete card is a BI00435C

[Giles]

Ok, I cant afford to go that route - I believe the usb card set alone is £1500+. The whole machine cost me about a quarter of that.

I'll keep an eye on a few forums to see if anyone is converting to mach3 etc and hope to get a 2nd hand board.

thanks

[Steve]

£606 for a USB top card.
£950 for the complete unit.

[Giles]

So I have got another complete board, untested, and it seems to act exactly as mine does.

With the whole board removed and nothing plugged in except power applied to the logic pins. Should I be getting an 8 on the display? As both boards i have give an L with flashing dot.

[Steve]

What colour is the 7 segment display? If its Red then its a Denstep control Card. If Green or yellow a nextstep.

stuff/NextStepLEDSWEB.htm

viewtopic.php?f=54&t=3167&p=16305&hilit ... ent#p16305

Does your board have a USB communication port?

You may need to try and connect the card to the computer to get the display to read correctly.

Where did the new card come from? What machine was it previously fitted in as it may need to have firmware updated.

Does the new board stay energised if you plug all the connectors back in?

[Giles]

They are both red displays.

Second hand board came out of novamill being converted to mach3. Bith have v2.1 on the chip so hopefully similar.

It stays energised so will try it plugged into the computer later.

[Steve]

The denstep card probably needs to download data before it changes the display.

L means the mint file needs loading.

see post viewtopic.php?f=54&t=3167&p=16305&hilit ... ent#p16305

[Giles]

I changed the top card and plugged into computer, which seems to have done the trick! Thanks for the advice.

[Giles]

Well it worked for a few days and now the computer wont connect, even though the card is energised, showing an 8 on the display etc. it was working then stopped with a timed out message half way through cutting.

I think i will bite the bullet and ugrade to usb. Does the £950 include the new software??

[tryagain10]

Hi

I have a similar problem. I've had my microrouter v3 for about 6 months now. When I first got it, I could not get the comms working. After reading loads of posts, I found the problem was a blown fuse (6.3A) on the denstep board. Happy as Larry!

Having not used it for a few months, I powered it all up again and the comms were not working again. Checked the fuse - it was fine.

An initial glance at the 7 segment display showed an "8", so assumed it was all fine, however it was a bit dim but thought nothing of it.

I've now realised the 7 segment display starts off bright with an "L" and the dot is flashing, but then about 1 second after power on the 7 segment display switches to an "8" and goes dim.

I've read this post and tested the 5v supply coming out of TB10 on 136 to OVERRIDE POTS starts off at 5v but drops to 1.4v when the 7 segment display dims.

Removing the top denstep board, the voltage remains at 5v.

The above description is from a "cold" start or when the machine has been left for a few minutes to discharge. If I switch the machine off and then on again after 10-20 seconds, the failure mode varies. sometimes the 7 segment does not light up.

Any thoughts?

[Giles]

I never got to the bottom if it. I replaced the top board and now works fine.