- Thread starter graffian
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wristpin
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Wedg1e
They call me Mr. Bodge-angles
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Probably a power supply failure in the display unit: I'd guess the scales need a nice regulated voltage to maintain accuracy, look for a blown fuse or dead voltage regulator IC... but I've never worked on one so am only guessing 
graffian
Seer unto the end of his beard
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I always knew eyeballing and poking, with my finger, would cure problem electronics!
The DRO is in a heavy old steel case and it's difficult to get to any of the boards when it's all together, so I pulled the motherboard and the other boards, attached a large ali heatsink to the voltage regs, which are usually bolted to the large heavy steel case; I was able to have it all connected together and all accessible.
I plugged it all in and had a little poke around, not really having a clue what I was doing, the display was upside down and I couldn't see it, anyway I poked around some more and decided I didn't know what I was doing, then I looked underneath the display and it's got "PF"[and PFF] showing! PF I guess is power failure, it is displayed after the power has been down, I cleared the axis and it worked!
In my excitement I moved one of the boards a bit and the whole lot, which was all balanced on note pads on the mill table, went tumbling on to the floor!
It has to be dead now right?
I unclipped the scale wires from the mill, why didn't I do that to start with and I laid it out on a worktop, I connected it all together again. Seems like the fall to the floor shorted some stuff and popped the 250mA fuses, I put new fuses in and it still works!
The axis that shows PFF when you move the scales the numbers are strange, it illuminates the wrong parts of some of the numbers[it's a VFD] and flickers all the numbers when a number changes, I swapped boards and scales and it looks like the problem is on the motherboard.
I was just about to accept I had to buy a 250 quid *****i dro.
The DRO is in a heavy old steel case and it's difficult to get to any of the boards when it's all together, so I pulled the motherboard and the other boards, attached a large ali heatsink to the voltage regs, which are usually bolted to the large heavy steel case; I was able to have it all connected together and all accessible.
I plugged it all in and had a little poke around, not really having a clue what I was doing, the display was upside down and I couldn't see it, anyway I poked around some more and decided I didn't know what I was doing, then I looked underneath the display and it's got "PF"[and PFF] showing! PF I guess is power failure, it is displayed after the power has been down, I cleared the axis and it worked!
In my excitement I moved one of the boards a bit and the whole lot, which was all balanced on note pads on the mill table, went tumbling on to the floor!
It has to be dead now right?
I unclipped the scale wires from the mill, why didn't I do that to start with and I laid it out on a worktop, I connected it all together again. Seems like the fall to the floor shorted some stuff and popped the 250mA fuses, I put new fuses in and it still works!
The axis that shows PFF when you move the scales the numbers are strange, it illuminates the wrong parts of some of the numbers[it's a VFD] and flickers all the numbers when a number changes, I swapped boards and scales and it looks like the problem is on the motherboard.
I was just about to accept I had to buy a 250 quid *****i dro.
