A couple of questions: How did you clean the bearings and what did you use to re-lubricate them?

Johnny: I don't know if you are addressing the question to me or to someone else. I did not clean the bearings, but only added some light oil as described above. The bearings turned freely before I added lubrication. They were just noisy. The scope is running in the other room now. I'd guess I've run it for about 90 minutes since re-installing the motor. I also have a Tek 465B but its fan is so quiet I can't even tell for sure whether it's running! I prefer using the 453 because it has sharper traces, and (at least so far) I haven't needed a 100Mhz scope. I have an HP606A due to arrive this coming week, and I expect to use one of the scopes to check out this "new" signal generator.
-DS

If you were asking me, I soaked the bearings in "turbine oil" for a few hours. They then spun free on the shaft before I slid it back together.
I think a small piece of one of the windings broke off and made the grooves in the rotor.
I got something out of it that looked like the wire a few thousandths long.
It turns for about a second and then stops. If it was larger, I would look for a centrifugal switch failing to go from start to run, but I can find no provision for that.
It does the same thing with the original cap and a substitute.
I think one winding must be opening up.
As soon as the OK comes through, I will ask the tek forum.
Thanks,
Pat

If the bearings are scored they will be noisy; lubricating them will not help very much. If there is dirt or debris inside you might be able to get it out with solvents and moving the bearing. This can take awhile; I've had bearings that seems to move freely, then started making noise later. The only thing to do is try again.

For the next time I have it apart, what would you recommend for cleaning? WD-40 for cleaning then synthetic motor oil for lubrication?
-DS

My 453 is a bit different than the one posted. I removed the 3 screws on the fan but I can't pull it out more than an inch. To make things worse while removing the fan screws the threaded keeper for the screws fell off and were very difficult to fish out of the chassis. I see no easy way to remove the fan. Taking the power supply out looks like a big project as well. When I removed the back cover plate a yellow wire broke loose or was broken off earlier. Any guesses as to where it attaches?
Keith

Where does the other side of the yellow wire attach to?

Is that a chassis ground?

The yellow wire connects to a banana plug labeled Z axis input positive signal blanks trace. The power supply must be held in by more than the four screws. I'm still trying to figure out how to remove it.
Thanks,
Keith

It looks way different than either of my 453 or the one Johnnysan posted. What does the front look like? What does it look like with the top cover off?
-DS

Here's some more pictures. I'm determined to gain access to this fan!
Keith

Yellow wire probably broke free from the ceramic strip. Bonus round question is where, if so. BAMA mirror site will likely have manual. Back in a few..

OK, BAMA evidently has service manuals for 453, 453A, and 453-2. You need to figure out which, if any, of these matches yours.
If model number sticker doesn't give it away, try looking at the mechanical drawings in the manuals. The external Z-axis input (yaller wyre) connection will be right next to the CRT cathode on the schematics. For example, on the 453 it connects to the junction of a coaxial cable (internal to the scope) and a capacitor. Easy, no? If in doubt, follow a few surrounding connections until you are comfortable that you have the right point. Then strip a bit of insulation and re-solder. There should be a bit of silver-bearing solder handy if you look inside the scope. It was on white spools hidden like an Easter egg.

Looked at picture, and, solder is right above your fan.

BTW, service manuals show blowed-up-real-good views. Sometimes have disassembly destructions too. Good luck with the fan!

On mine, the Z axis wire connects to terminal 4 (from left) on the ceramic strip just under the fan.

I had the same problem with hardware disappearing inside.
Removing the four screws on the transformer did no good.
The plastic screws on the top small circuit board will let you lift it enough to get a grabber inside to get the captive nut. (you may need to turn the scope on it's side to move the nut to an accessable location).
My motor had full-length leads and came right out of the unit.
I just can't seem to get it to work.
Pat

Thank you Johnnysan. I got out my magnifier and I can see a small hole where the wire once connected. Thanks for the photo.
Keith

When I re-attached the yellow wire to the ceramic strip I'll need to use the special silver solder correct? Is the solder that's on the spool next to the fan have a flux core or will I need a special flux?
thanks,
Keith

Yes, the solder on the spool is silver solder. I have used regular solder in Teks with no problem.

There's been a discussion on the 453 fan bearings on the Tekscopes yahoo list.

If you have the ball bearing version, you can get replacement bearings at Home Depot. The report is that the Diablo brand router replacement bearings for their router bits are correct replacements. Item DR62XXX has four bearings and a hex key. The 2 middle-size bearings, 1/2 inch OD and 3/16 inch, ID fit.

I haven't tried this yet, just passing it on.

Those sound like the right size. Next time I'm at Home Depot I'll look for a set. Another part number I just gleaned from the Yahoo Tek group is type R3ZZ ball bearings. These are supposed to be widely used by the RC folks, so a hobby shop would be a likely place to look.
-DS

The router bearings work but they growl. If you have a local source of some permanently lubricated high-speed bearings, try them first.
An old trick - use the old bearings to seat the new ones, that way you don't push on the retainer and destroy them. Trying to replace the locking clip requires care on the fromt, one slip and the pliers hit the retainer.
Pat