Orac problems please help!!!

[andy-brown69er]

Hi everybody! I am having big problems with my dads orac lathe, we just had the inverter repaired and now the VDU does not power up at all. It did before but after reconnecting everything the VDU has all of a sudden stopped working as well as nothing on the front panel working (no power there at all!). I did electronics at college but that was 6years ago and I haven't done much in that field since! Any help would be gratefully appreciated!
thanks Guys (and Girls? )
Andy

[Denford Admin]

I'ts difficult to know what to suggest...
have you got enough of the Orac drawings to start fault finding ?
viewtopic.php?f=15&t=400

Obviously, a fairly decent multimeter will be a necessity, and start by checking all the fuses you can find !

[andy-brown69er]

Thank you for your reply i will check all the fuses on all the boards and hopefully be able to find something out. I also have a cable that appears to go nowhere! it is a grey cable with a blue, a red and a screened cable inside it runs around the the left hand side of the machine i will try and find out where it actually goes to at the front of the machine to make it a bit easier for everyone!
cheeers in advance
andy

[andy-brown69er]

Ok so i have sorted out the VDU problem! Found out i crimped one of the cables on he plastic! ok now for the cables that go nowhere!! I got a red, blue and screened at one end and red and blue at the other that goes onto PC1601 please check the diagram i have supplied to see where they go! At the moment I have no chuck movement at all but I have managed to fix traverse problems by replacing x2 metal paper capacitors on the little power board on the front. When I press the spindle start button on the front I can hear and see the relay moving on the PC1601 board but still no movement of the chuck!!!
hope someone can help can't wait to get the thing off me bench so I can start another project!!
cheers
andy

[Martin]

As looks as though the 2 core screened cable goes to the Parajust which is the spindle drive on the right when you are looking from the back.
The drawings show the red from the PC1690 board (TB"F" terminal 18) going to TB1/2 on the Parajust drive.
The drawing then shows the green from TB"F" terminal 17 going to TB1/1 on the Parajust drive.

The drawings do state the cable is a 4 core screened cable so I guess it was changed to a 2 core so the green has been changed to a blue.
I have attached a scan of the terminals on the Parajust drive unit.

Hope this helps

[andy-brown69er]

my parajust differs from the drawing slightly. The big transformer at the back by the filter capacitor is actually up above the parajust behind the spindle motor (where the belt is to drive the chuck)
There are two cables going to the transformer one from the negative of the filter capacitor and the other goes to a black connector on the left of the parajust with three other cables coming from it!
Thank you for your help previously it would seem that someone has had a go at modifying this machine at some time and has left the spindle not running at all!
If any of the above is unclear (which i am sure that it is) I will upload some photos soon to clarify!!
thanks guys you are true gents!
andy

[Denford Admin]

Hi andy - can you try to resize your pics please - I struggle to see what's going on when the photo's stretch the forum out, and they also take up a lot of our precious web space.
Try the quick resizer program from here: viewtopic.php?f=17&t=823
Cheers!

[Martin]

It looks similar to how I remeber them.

The choke was removed fron the drive & fitted in the end at Denfords.

Have you tried putting a meter on the twin wire that you have extra?

If it`s the analogue then it should read up to about 10 volts DC depending on the requested speed.

[andy-brown69er]

hi guys please delete the photos to free up some space and I will re-upload somewhere else and put a link on the website so it doesn't take up any space!I think that that is the easiest solution. I agree that the photos are difficult to view i'll sort it out.
Thanks for all your help guys!!
andy

[andy-brown69er]

resized photos!!
by the way the blue red and screened cable problem has been sorted thanks to you Martin. In the photos you can see where the transformer used to be there is what looks like a capacitor going across the red and blue cables. When you posh the spindle start in manual mode you can hear a relay click but the spindle just won't start up at all.
thanks again everyone!!!!

[Denford Admin]

Thanks andy, but no need to put pics anywhere else - we have enough space for photos as long as they're around 100Kb in size and not 1000Kb.
It's better for the long term, as it can all be backed up together - other hosting sites may not be around in a year or two whereas (fingers corssed) we will be !

[Martin]

It may be a faulty drive unit.

Have you seen the manual for the Parajust?

viewtopic.php?f=15&t=462

It may be worth checking that the drive has power, start stop signals are correct, & the analoge is correct.