Faulty Triac

[MayaTekla]

Hi all,
We have a triac circa 1985 here, It has perhaps been sat for 3-5 years but was fully functional previously.
When powered on the vdu powers up (both of them) and displays various info including a note to press abs datum button to start datum. It seems no buttons on the keyboard do anything apart from the emergency drive stop, switch which seems to engage and disengage a relay on the power board marked as RL2.
When powered on RL1 clicks on and off about once a second repeatedly, we suspect the problem lyes here somewhere but are struggling to identify it.
Does anyone have any ideas?


(On a side note, this may be better in the electrics forum section if an mod wants to move it)

[Denford Admin]

I found some reference to RL1 in this manual:
viewtopic.php?f=47&t=3172

but not sure if this is relevant to the control you have or not ?

[Lasergraph]

It appears that the Keyboard is not functioning as in the power up mode we can not get any of the keys to display a value on the VDU when they are pressed.

It has also been suggested that a keypad fault could be the cause of RL1 pulling in momentarily and then immediately dropping out again about once a second.

Does any one have a spare keyboard or a working keyboard for sale to replace the one on this machine to see if this is the problem?

Best regards

Stuart.

[MayaTekla]

Have you tried removing both keyboard ribbons and powering it up with no keyboard?

[Lasergraph]

The next thing we are going to do is to try a boot with both of the keyboard ribbons disconnected and to see if that stops the relay problem.

We will also buzz out the input lines to the output lines and check to see that the keys produce the expected cross-points.

Depending on the functionality (or other wise) of the keyboard we will be able to take a view going forwards on how to proceed.

We will also try and look at the the keyboard driver chip and the keyboard receiver chip to see if they are responding as expected.

Any other tips, hints or wrinkles guys?

Best regards

Stuart

[Denford Admin]

Have you seen this info which may help ?
viewtopic.php?f=4&t=1700

[Lasergraph]

Hi Admin

Yes I did manage to find that set of posts, thank you very much for being kind enough to point it out.

That is the one I am going to use to try and buzz out the inputs to outputs on the keyboard cross-points to see if our keyboard is working or if I need to try and fix it.

Has any one got any information on how the keyboard is made, how its removed, can it be opened up and cleaned / worked upon?

Many thanks in advance.

Best regards

Stuart

[angel-tech]

I know someone with an early triac like yours, and i conveted it to Mach3. So the front panel is used just to cover the front. I'll ask him if he's interested in selling it.

[Lasergraph]

Many thanks for that I would be really interested in getting hold of a new front panel keyboard.

Do you have any documentation on the conversion to Mach3 as it seems to be the way every one is going but I am no CNC expert.

When I do get my Triac running then I have to start from complete scratch to learn how to drive it and use it.

I am a good electrical and electronic engineer so with sufficient documentation and support I may feel brave enough to try the conversion to a Mach driven machine in the future.

I am however fortunate that the machine came out of a training school and I have all the training material that they used to use to train apprentices from scratch as well as all the manuals etc for the machine.

If any one is interested in the paperwork I have I am sure I can scan and pass to Denford Admin to post and host as appropriate.

Best regards

Stuart

[Lasergraph]

I have already had some really good support from one of the forum members with regard to trying to get my device up and running in its original state and this is the route I intend to go down to start with as I have all the documentation to learn away from what I would then have in front of me.

However are there any members of the forum who could do a "TurnKey" conversion to Mach on a commercial basis and if so what is a typical cost for doing such a conversion?

Best regards

Stuart.

[Lasergraph]

Hi all.

I have opened the machine and disconnected both of the ribbon cables to the keyboard.

I then booted the machine, this stopped the relay RL1 from pulling in and dropping out as described above.

The machine was then switched off and the two keyboard cables were re connected and the machine rebooted.

When the machine came back up and the clicking relay fault had returned.

I guess that the next thing I need to do is now disconnect the keyboard again and do the crosspoint checks.

Best regards

Stuart.