Bridge port DRO Wiring Diagram/Schematics

[oddballcraftworks]

My company recently picked up a Bridgeport mill for basically scrap metal price. The DRO turns on but just displays 0's when you move it in the x direction and just flickers up one digit down one digit in the y and the problem changes if you move the cable from x to y, I am not sure if the cables are good or if there is a readout issue if anyone knows what pins have power and which are inputs it would help me figure this out.

 

[markba633csi]

If you don't have an electrical-minded buddy nearby, about all you can do is try cleaning the scales and the connectors and see if that helps
Maybe tap on the display unit, perhaps a loose part or wire inside you can locate. See if you can find a schematic diagram for it online, that would help immensely. If you have a scope you can poke around on the connectors and look for the quadrature signals from the scales, usually 5 volt TTL
Equipment bought for scrap prices is often just as advertised- scrap
-M

 

[oddballcraftworks]

I spent a few hours yesterday searching and came up with nothing online except one member here posted the user manual but no details on wiring or other electrics.

 

[markba633csi]

Sometimes you can get surprisingly far with just a scope and no schematic, if you can figure out the "lay of the land" of the circuit board
Check the obvious things common to all digital circuits like clock signals, power supply, etc. Clock oscillator modules sometimes fail.
You might find something simple and easy to fix- you never know. Earlier TTL circuitry is easier to troubleshoot than modern ASIC based stuff- where replacing one big chip is sometimes the cost of the whole unit- 74 series logic is plentiful and cheap
-Mark
ps Out and out failures are easier to fix than flaky intermittents, so I think your chances are good
pss You may be out of luck if the unit contains an EPROM and is more than 20 or so years old- they do self-erase after a time

 

[markba633csi]

If you can post a clear pic of the circuit board component side I might be able to give you some help/pointers
-Mark

 

[hwelecrepair]

If the last digit is flickering and the only one flickering, I have seen that mostly being a reader head issue.

What DRO make and model do you have? You said the problem changes when you plug X to Y and Y to X. How does it change?

Jon

 

[oddballcraftworks]

My employer has decide dI have spent enough time working on and is ordering a new set of scales and DRO