Post By slim pickens
The BP I just bought has a 'vintage' Sony Magnescale LF-200 DRO. The readout powers up fine and Y axis works and reads, but X axis only reads "0" and will not count when table is moved. Could be wiring issues, have not yet tried swapping cables or looking for stuck buttons, etc.
Does anyone have a manual or wiring diagram, or other electrical troubleshooting info (expected cable resistance, scale output?) for this unit? I know it is a shot in the dark, but here goes.
Nobody have any info? I did some quick diagnostics last night. The X readout stays blank when powered up with X scale connected. Y scale and readout work fine. When I Hook Y scale to X readout, and X scale to Y readout, the Y readout will work fine (so X scale is good) but the X readout reads 111.1111 with the (obviously also good) Y scale. Sounds like it is internal to the readout. Anyone have any tips on what to look for inside there, other than fried resistors, popped capacitors, etc?
If you had posted four weeks earlier you could have had mine for the price of shipping. Sorry, I gave it to a Sony readout technician aquaintance. My issue was with the scales.
Awwwww $(&^#.... a day late and dollar short, as usual....
Might the sony technician friend have access to a troubleshooting manual? Or want to trade a working one for a semi-working unit?
I have yet to open it up and see if it is something obvious... hopefully will do tomorrow.
The tech is not a friend. I was put in touch with him through a surface grinder rebuilder through whom I bought a rebuilt Mitsui. The old Sony readout that came with it did not have the resolution which I needed (.00002) so he gave me a great deal on a new magnescale setup. I thought I'd return the favor by giving him my old readouts for parts. They don't seem to bring much on ebay anyway. I know that the technician asks three hundred dollars for a simple exchange of functional obsolete display units(I asked), and he does repair them as well. We are in the Chicago suburbs, but you can probably find a repair facility closer to you. If you have the time, try to get another display on ebay.
Update: I finally got a chance to quit cleaning the BP and take a look at the DRO readout. As stated earlier, swapping the scale plugs resulted in confirmation of a bad X readout and 2 good scales.
I am generally pretty good (really good?) at troubleshooting because of my good old dad. He let me learn by doing, and then would point out ways to improve next time. The one that has saved my bacon more than once (and did today) was to always FIRST check ALL the stupid, obvious, or "easily tampered" stuff. IE make sure it is plugged in, full of gas, fuses not blown, etc, before tearing into something whole hog.
Well it paid off again. I plugged in both scales and noticed the resolution selector switches looked a little askew. I flipped them a few times to make sure they fell into their detents. Nothing changed, the X scale still flashed 111.1111. I flipped the direction switches, same effect, nothing. I toggeled between inch/metric and VIOLA, it starts reading in metric. HOT DAMN, now we are in business. I powered it down, toggled the switch a dozen times, powered it back up and the inch readouts are both 100%. So there is $700 that can stay in my pocket, an oldschool Sony DRO gets a new lease on life, and I dont have to keep scrounging for info or parts.
I think I have some data on these Sonys. We have many of them and they are still working accurately after 20+ years. I'll check on the manuals if interested.
Yes please! It seems to be 'workin all the way' now so a manual would be helpful for programming, future troubleshooting, etc.
I looked on the sony website but did not turn up much.
I would gladly pay copying costs, postage, etc.
I have the instruction manuals for the scales and display if that helps. What scales do you have? GP series? I would assume so. These manuals are like 15 pages in 5X8 size booklet.
These DROs have been bullet proof for us. Our first one is now 27 years old. I am not sure we would have gotten that kind of service from optical scales. I have never had to have one serviced or repaired.
If of any use let me know.
The tags on the scales are both severely worn/faded, but appear to say GP 27XX or GR 27XX, next line is the serial number, next line only says Sony Magnescale.
I am glad to hear you have gotten good service out of your Sony DROs. This one is definitely old, and looks to have been in a production or industrial environment for a long, long time. Hopefully it will continue working well in a less demanding environment.
I will PM you with my contact info.
Hello Bluchip, any chance I could buy a copy of the Sony LF-200 manual? I have this same unit on a Bridgeport I bought for HSM use a few years ago. The owner told me they were a very reliable unit. So far, no problems. They won't do bolt circles and it does have kind of funky switches for setting numbers, but it works and works well. Ichecked it for accuraccy with gage blocks and was impressed with it's performance.
We can set you up. I've sent you a PM.
I really like these old DRO's. When we bought our first one in '89 they were like $2400.
I don't think the Bridgeport was $4000!!!
The only problems I remember was a shop accross town burned out "elements" of the LED. That's kinda bad when the very upper right vertical bar of a digit burns out.....it makes an 8 look like A 6!!!!! They have a rather archaic tumbler thumbwheel for the preset. But this is neat...occasionally we set a referance number in these "preset windows" but do not push the button. We leave that coordinate there to remind us of another location, origin, etc. You can't do that with touch pad style. The selector on the side toggles it to diameter read also, so it is possible to read the diameter of part when milling round on a rotary table..neato.