Before you give up on it, there's one thing you can try.
Remove the magnets from the frame of the scale and be sure they're clean, nothing sticking to them, ferrous or otherwise.
Do the same with the recesses they sit in.
Pay attention when you're taking them out as to which way they're oriented, as in, which magnetic pole faces where.
Then re-assemble them and try it.
If it works, good. If it doesn't, play with changing the orientation of the magnetic poles. The previous owner may have had the scale apart and put them back wrong, if that's possible.
I have a 5-0-5 that did the same thing yours does. I tried everything you have, and finally removed the magnets and cleaned them. I didn't find any major smoking guns, but when I re-assembled the da*n thing it worked, and has ever since. Go figure.
A friend had a similar problem, he solved it by passing a ferrous item (I seem to recall he used a large screwdriver blade) back and forth in the scale slot between the magnets several times.
Magnetism is interesting stuff with a little bit of witchcraft mixed in, at least that's the way it is for me.
When you've nothing better to do, this is an interesting video on rare earth magnets and a chunk of copper pipe. I looked at this, and being a skeptic, had to try it for myself. It works! There are dozens of similar videos, I just picked this one.
https://youtu.be/NqdOyxJZj0U
The reason the copper blade and magnets dampens the movement of the beam is that the magnetic field resists the motion of the copper through it. If there's no motion, nothing happens. Same as a generator, which is a copper winding moving through a magnetic field.
The video in itself won't explain what's going on with your scale, nor will it explain how it's fixed if what I suggested works. At this point, you've not a lot to lose by trying it.
If it works again, I'd recommend removing the beam from the scale frame when you're not using it.
Copper isn't entirely anti-magnetic, just very low level. And, the blade on the scale is probably not 100% pure copper.
If it sits in the magnetic field long enough, it will be very slightly attracted.
Remove the magnets from the frame of the scale and be sure they're clean, nothing sticking to them, ferrous or otherwise.
Do the same with the recesses they sit in.
Pay attention when you're taking them out as to which way they're oriented, as in, which magnetic pole faces where.
Then re-assemble them and try it.
If it works, good. If it doesn't, play with changing the orientation of the magnetic poles. The previous owner may have had the scale apart and put them back wrong, if that's possible.
I have a 5-0-5 that did the same thing yours does. I tried everything you have, and finally removed the magnets and cleaned them. I didn't find any major smoking guns, but when I re-assembled the da*n thing it worked, and has ever since. Go figure.
A friend had a similar problem, he solved it by passing a ferrous item (I seem to recall he used a large screwdriver blade) back and forth in the scale slot between the magnets several times.
Magnetism is interesting stuff with a little bit of witchcraft mixed in, at least that's the way it is for me.
When you've nothing better to do, this is an interesting video on rare earth magnets and a chunk of copper pipe. I looked at this, and being a skeptic, had to try it for myself. It works! There are dozens of similar videos, I just picked this one.
https://youtu.be/NqdOyxJZj0U
The reason the copper blade and magnets dampens the movement of the beam is that the magnetic field resists the motion of the copper through it. If there's no motion, nothing happens. Same as a generator, which is a copper winding moving through a magnetic field.
The video in itself won't explain what's going on with your scale, nor will it explain how it's fixed if what I suggested works. At this point, you've not a lot to lose by trying it.
If it works again, I'd recommend removing the beam from the scale frame when you're not using it.
Copper isn't entirely anti-magnetic, just very low level. And, the blade on the scale is probably not 100% pure copper.
If it sits in the magnetic field long enough, it will be very slightly attracted.
