Please Help T3F problems

Good point on the already heavy weight of a stone body Koetsu. I neglected to take that into account.

I can tell you that Raul does not have Apogee speakers.

You are correct in noting that there is a huge difference between your two cartridges.  You could, in the interim until you can get the T3F fixed, move the Koetsu to the LP12, but you need a very high effective mass tonearm to get the most out of the Koetsu, and I don't know anything about the Ittok.  The good news is you can increase the mass of the Ittok in any of several ways, as simply as putting a coin on the top of the headshell.  A US nickel weighs 5g, for example.

I saw the Reference ensemble at a high end dealer's showroom, once, but do not recall having heard it.  It was really a milestone product in the sense that it blew away previous conceptions of what even "expensive" turntables should cost.  I would parallel it with the Infinity Servo-Statik One (a shocking $2000!!!) or the later multi-drive Heil/ESL from Infinity (with the massive rosewood wings to block phase cancellation), which was even more costly, for those days.  And from there, prices only went more crazy in the 21st century.

Which you like, I guess. Yes?

If I recall correctly the T3F made its first appearance on the Reference as part of an ensemble that also included the dedicated stand.

Mijo, The "T3F" refers to the Rabco-like tonearm that was marketed by Goldmund, originally I think with their massive Reference TT, which was then the most expensive TT/tonearm combo available, at least on this side of the Atlantic and Pacific.  I don't think the OP has a Goldmund TT.  And he wants to make his T3F work; he's apparently not interested in a replacement tonearm. Did you actually find the Reference TT to be problematic?  HP loved it for years.

Have you been helped by the internet resources I mentioned?

I certainly agree with Dover that you are better off with the ET tonearm, but that involves a larger cash expenditure. On the other hand, you might justify it by thinking that the T3F will likely be problematic in the long term, even if you fix it right now.

Seems like one of those guys on the Lenco thread(s) actually fixes Rabco tonearms for other owners.  That's where I would start, if you don't get any DIY hints from other reading.

I googled "Rabco tonearm owners group" and found this group on Lenco Heaven:

https://www.lencoheaven.net/forum/index.php?topic=18696.0

Those Lenco guys are very helpful.  There are more such sites, if you care to google the topic I put in quotations above.

I gather you sourced the information referenced by Raul in his post above, which takes you to Soundfountain, and Soundfountain provides some valuable info on the mechanism, and a diagram of the works, if you follow the path on Sf. The results you got with the arm disconnected might just mean that disconnecting the arm confuses the servo as to where the arm is in its path to the spindle. Info on the Sf website indicates there are two motors, in both the Rabco SL8 and SL8E. We might assume that the T3F resembles the SL8E, since it post-dates the latter Rabco. Anyway, the motor to drive the pivot toward the spindle is evidently housed in a small black box that rides on the rail. The second motor apparently has only the job of raising and lowering the arm wand. (You probably know all this; I am just thinking out loud.) If you haven’t already seen the diagrams on Sf, then maybe it can help.

I would bet there are Rabco aficionados out there somewhere.  Meantime, if you can by close examination figure out where those contacts that turn the motor on and off are located, you might try just cleaning them very carefully and gently.

I have no direct experience with T3F, but I am under the impression that it was an expensively constructed upgrade of the original Rabco tonearm.  The Rabco was a straight line tonearm that actually relied upon pivoting to make its way across the LP surface. The arm wand was free to move in the horizontal plane. As it moved it periodically closed a microswitch installed at the pivot point. The switch then activated a tiny motor which moved the pivot point along a rail.  Movement of the arm wand associated with the motor drive would then open the switch and turn off the motor until the arm wand arc-ed back to activate the switch again. Your problem could be caused by (1) failure of the switch, or (2) failure of the motor to turn off.  I would suggest you do an internet search on the Rabco.  Perhaps there are Rabco aficionados who are very familiar with your problem and can help you find parts if needed or just show you how to clean the switch contacts.