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Help with a 1980’s Tri-onics DRO Repair


Mar 5, 2024
Melbourne, Australia
We have been asked to repair a digital display board which is connected to a Trionics Milling Machine. We believe there is several issues with the board, but we believe it’s repairable if we could get our hands onto a manual and especially a circuit diagram.

The Manufacturing label on the back of the display panel has the following information:


P/N 007D120001-002

S/N 0155

So far, our efforts to contact anyone who may have worked or know of the Company have been fruitless.

Can anyone help us with information on the Digital Display Board please?


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What problem is it having? I have a similar older DRO (from Dynamics Research Corp). It has had a few problems over the years.
One was loose wires on the "Y" slide sensor part. That was fairly easy to track down.
The other problem was tricky - the "X" axis display died one day in the middle of a project. I took the PC board out and examined it under magnification. Turned out a tiny blob of stray solder had worked it's way loose and landed between the leads of the "X" circuit voltage regulator chip. I pried it out, and it worked fine. Fortunately the 7800 series regulators have built-in short circuit protection, so the 'magic smoke' didn't escape the chip.

Anyway, it would pay to do a careful visual inspection of wires & stuff, before delving into the more complex fixes.
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