AMI Seville 1100 Tone Arm Skipping

Hello, while I await delivery of my Rowe manual CD from Canada I picked up another juke today. (I know, I have issues). Anyway, I was told the machine worked fine until it was moved from one room to another in the house where it was kept. Upon relocation, the juke would select and position a record, but the tone arm would not rotate over to the play position. Once I got the box to my workshop and opened her up, the first thing I noticed was that there was a TON of white lithium grease EVERYWHERE. Seriously, some chucklehead squirted this stuff in EVERY mechanism that has moving parts. I presume that I will need to clean all the extra grease away and relube with the correct oil.

With that said, I attempted to manual move the tone arm while the machine was in the service mode and noticed it was frozen in place horizontally. I lifted it up and down a few time and lightly "flicked" the crescent piece at the back of the tone arm with my finger. After doing this I put the machine back in the "on" mode and made a selection. Once the record was placed on the turntable, the tone arm moved, but barely missed the edge of the record. I adjusted the horizontal positioning of the tone arm and made another selection. This time the arm landed on the record perfectly and began to play, for about 3 seconds, after which the needle began skipping. I picked up the tone arm and gently placed it further along on the record with the same result, about 3 seconds of song playing followed by continual skipping.

I remembered see this thread regarding tone arm adjustment on the 1100 (viewtopic.php?f=3&t=7606&p=34827&hilit=tone+arm#p34827) and made the recommended adjustments. Records played a tad longer, but eventually ALL started skipping before halfway through the song.

I also attempted to adjust the tone arm counterweight, with little success.

I am certain that this is a simple adjustment and that I am just missing something. What is that "something?". What other adjustments do I need to try to get the skipping to cease?

"Waterborn" -place the mech in play mode, lift the tonearm with your thumbnail and try to get it to stay on your nail all the way to trip.

if it does not get stuck at some point it indicates that the lift lever is not clearing the crescent shaped vane when in normal record playing height.

If it does slip off the fingernail and feel stuck: Flush the bearing and post thoroughly then relube w/20wt oil. Check also for binding or bias caused by the tonearm cables and eliminate the 'no record" leads -they just add drag.

Properly set-up this arm can track at as little as 1 gram. I run them at 2gm.

Rob

Excellent, thanks for the reply Rob. I will try these tips later today and let you know what happens. To be clear, when you say to put the mech in "play mode" you are indicating that I should let it choose and begin to play a record, yes? I know this may seem like a stupid question, but being new to all of this I want to ensure I fully understand your instructions.

Thanks again!

Dane aka Waterborn

OK, well two steps forward, one step back it seems. I made the suggested adjustments and checked the items listed above. It seems that the tone are wires that connect the cartridge to the speaker input wires were binding up the tone, making it skip. I did lube the tone arm Bearing and post as well.

Once I was able to confirm that the records would play to finish and tested several selections, I realized that one of the speaker channels was not giving any output. At first I swapped the speaker input wires and only the left channel would work, though both sub-woofers in the front panel would work, regardless of which input wire was plugged in where. So I figured that I must of tugged one of the wires running from the tone are to the speaker input wire, so I reflowed all solder point one the connection point between the two to ensure proper connection. Now only one channel input was working, but when I swapped the input wires, I could get one or the other upper speakers to work. So obviously the speakers and amp are fine. So I presume that this issue is between the stylus and the speaker input connection. The connection where the input wire goes through the metal brace to the tone arm side seems pretty wonky. If I slightly tap it while a record is playing, the "good" channel will go in and out. I also noticed that one of the small pin connectors on the cartridge was lose, so I crimped that slightly, to no avail. Before I go and order a new cartridge, does anyone have the schematic for this wiring? I am still awaiting the arrival of the darned manuals from Canada. Anything that I could be missing here?

Thanks to Ron, Rob and everyone else for the advice and guidance.

Dane

Dane,
I do not recall the "path" of the tone arm wires on that model, but it would seem to me that if you have a meter, you could follow them from the amp input to the cartridge ?? If that amp uses the three wire "oblong"A-MP input plug, you can just turn it over and plug it in the other way--center lug is common--outer two are, one per channel. Ron Rich

Here is a wiring diagram:
http://www.verntisdale.com/schem/jbm-200.jpg

Did you measure the impedance of each channel at the RCA plugs? It should be in the area of 600 ohms. I doubt the cart is at fault. this was the first machine I placed on location back in 1984. A typical problem I found in all the 1100 series was broken wires at the 7 pin connector.

Do note that the cart must be wired out of phase since the bass speakers are across both channels for mono bass.

Do you have the tube power amp? The tube amp should have the coupling capacitors replaced. Also, look for burned 100 ohm resistors at the 7868 tube sockets. These act as fuses when a tube shorts internally.

The transistor preamp used in both models should have it's electrolytic capacitors replaced, but that is not critical.

Rob

Rob, thanks for the schematic. I presume that the socket/plug part of the diagram indicates the circular fitting that passes through a metal piece to the left of the tone are assembly. Is this correct? These wires are so small and delicate, it seems like that they may have loose connections, either at that junction or further down the tone are at the cartridge connection points.

Stupid question - how do I measure impedance at the RCA plugs? Is it common practice to recap the amplifiers on these machines? I have read several post elsewhere that indicate this is standard practice when troubleshooting an old machine. I am fine with soldering and have recapped dozens of arcade monitor chassis, so doing so would not be an issue for me.

I do believe that I have a tube power amp, but will take a picture to confirm that I am correct in this belief. I will check for burned out resistors tomorrow as well.

Thanks again for the input.

Dane

presume that the socket/plug part of the diagram indicates the circular fitting that passes through a metal piece to the left of the tone are assembly.

Correct.

how do I measure impedance at the RCA plugs?

With the pickup (7 pin connected) you just use the ohm function on your meter to measure the resistance between the shell and center pin on each RCA male plug.

Is it common practice to recap the amplifiers on these machines?

In the transistor preamp the danger of damage is minimal, but performance in terns of bass response and channel balance are compromised when caps dry out and lose value.

It is highly recommended -especially when tubes are involved due to the much higher voltages and heat. The power amp is very simple and there are not many caps to replace. the tiny ceramic disks can be left as-is and the electrolytic caps -may- be Ok as they were American manufacture and held up well. make sure you replace the bias supply caps. If these fail the loss of bias can kill the output tubes and sometimes output transformers too.

-Make sure the amp fuse has not been increased.

Rob

OK, played with this some more today and I am sure that the issue lies somewhere between the cart and the RCA plug into the pre-amp. I can connect one of RCA plug leading from the tone arm into EITHER channel input on the pre-amp and I get sound out of the speakers on that side of the box. However, if I plug the other RCA plug into either input, I get nothing. My guess is one of the small wires (either in the junction at the metal plate or on the cart itself) came loose when I was messing with the tone arm itself. What confuses me about the wiring and the drawings is what the 3rd wire on each channel coming from the cart is for. I get there is a primary signal wire and a ground, but what does the third wire do and how should it be connected to the junction point at the plate?

There is no "3rd wire"--that circle symbol indicates a "drain" (usually a braid, surrounding the wires) which it shows is connect at the amp end thru the "plug" and dead ended, just prior to the cartridge. (connected, like all other wires in that drawing, ONLY at the "dots") Ron Rich

OK then, why are there 6 wires going into the 6-pin connector at the metal flange? (see photo)



Also, there are several more wires attached to the metal tab to right upper right in the photo below. What purpose dose this connection serve?

Duane,
Look at the schematic--I assume the drain is the connection 3 to five and 4 to 4 on the plugs--look where that terminates, at the cartridge end, on the print--- nowhere ! Ron Rich

Hello Duane,

Looking at your two pictures of the phono connection socket (valve base type socket) the wires are not in the correct positions for one of the channels.

Regards
Alan

Alan Hood
ami-man
UK

So I removed all four wires coming from the tone-arm, cleaned each tab, reflowed new solder & reconnected each signal and ground wires from the tone arm and now I have music out of BOTH sets of speakers. (see video linked below)

https://youtu.be/lkZ4Si4sTpA

The "extra" wires in question do appear to be part of the drain mentioned earlier. Apparently one (or more) of the wires was soldered to the tab but not making a good connection.

Now the only issue I have with this box (aside from it needing some lubing and a good cleaning) is that the cable that controls the song selection indicator has snapped off, so the wheels do not turn when a selection is made.



Is there somewhere that I can order a replacement part for this? I presume that I will need to replace the entire apparatus, including the gear and post.

Please read the announcement posts above--parts suppliers are listed there.
Ron Rich