M100A sort of running :-)

Hi All,

I got the M100A parts all up to my flat which is on the 2nd floor. A lot of trips up and down the stairs today!

I put the parts in and it sort of works. I adjusted the tone-arm as on the a-side it did not lift off the record but dragged across it. Now it lifts like it should and clears on the return.

However...
Now on the same side it gets to the end of the record and starts to hang and not roll off toward the center and reject. At first I thought it was a bad record, but it seems to be doing it on most of them.

Also, the mechanism is acting funny. I select a record and it goes and plays it. It them just starts scanning back and forth and back and forth forever...

Anyone ever seen this behavior before.

I am getting close to getting this thing complete and working.

One more thing, every now and then for a few minutes is sounds like a gear or bearing is making a thump thump sound. It does it and then goes away. Does the main drive shafts use bushings or needle bearing on these things ( I will look it up later). It sounds like a needle bearing with a bad spot.

It was nice to hear the thing play in my living room.

Best, James

Hi James,
Glad you did not axk me to help you bring that thing upstairs--I saw them thar stairs, whew !!
As for the tone arm problems--could the tone arm wire be "hanging-up" on that side (only)--I've seen this on the 45 rpm players, once in awhile--
The continual scan problem, I understand was a common problem on the A's. It relates to the way the SA unit is mounted, and is the reason they mounted it "upside-down" on the 45 rpm models. "Stuff" falls into the SA unit and shorts the grounding bar out--thus causing the phono to continually scan. The other thing that could cause this (on any SA unit model) is the motor carry over switch. Not sure, exactly where this is on the A's--but I think you can determine which one is causing the problem by opening the single wire connector between the ES and SAU. If the motor runs with this disconnected, I would strongly suspect the switch---or just had another thought--magnetized play control relay armature, in the "stepper box" ?
HTH, Ron Rich

Well,

After two days of hitting my head against the brick wall...I ran down most of the issues.

The ground wire to the pin-bank was open. The copper opened about 1/8" behind the solder under the sheathing. Look fine. Was not. If that ground is not good you get everything working but is just keeps scanning.

This would make a good joke if you have someone with an "A" and want to drive then nuts

Of course, before I found it, I cleaned and checked every contact point in the selection box for the third time.

By the way, the "Reversing Relay Latch Lever" adjustment is VERY finicky. The book says .005 to .010 but be careful. I used .008 and the "A" side would start to load then stop just before the record was loaded. I do not pretend to know exactly why. I readjusted the lever to .006 and it now works fine. Stay at the low end of the specification. When I started it was zero.

Also, one more thing on the "A". The worm bearing block. This is the block with 4 screws that has the large rectangular felt oil block. In this block there is below the large felt and small round feeder felt that goes into an oil gallery that ends at the bushing. The problem is that on my unit, the bushing was not drilled. The oil just stopped at the outside of the bronze bushing. The worm shaft, inside the bushing, was not getting any oil. I drilled it as the housing was cross drilled prior to the bushing being pushed into it. I then silicon sealed the opposite hole. Now the bushing and the top of the shaft is oiled. I do not know if it was a factory screw up or if someone put into a new bushing in the field and did not put the hole in it.

Now I have to do some fine adjustments for the drop onto and pickup from the records both 10" and 12" and then other than the animation tray I am good to go.

Best, James

Hi James,
Not quite sure about the "open ground" ?? Seems to me if "open" it would not scan ??? If "shorted", it would hold the play control relay energized ??
MY, words of "wisdom"--if it ain't broke, do NOT "adjust it" !!

Hi Ron,

That wire that goes to the end of the pin bank, I hade used a jumper on the bench, was bad at the solder joint. I took the end off, remade the connection and put it back and the scanning forever stopped.

With that last item, other than lead in and out adjustments on the record, that is it.

I am sitting here typing and running through every record to make sure all the pins are doing their thing. So far it is a pleasure. I have it on the back wall facing the hallway and the stairs. So the sound travels well directly to my desk in the study.

Thank you again for the help. I will get ahold of you in a week or two and come down to see if I can barrow the "A" animation stuff to duplicate it...I think I may have someone who will sell me one...also, I want to get a free play adaptor for it. Sondra has asked me to get a remote volume control so we do not have to roll it away from the wall to change the volume. If you have one I will get it from you if not ebay.

Since someone drilled a hole in the front panel, I am thinking of putting in a push button on-off switch in it and putting in a remote switched power strip inside the case so the unit can be turned on and off completely from the front.

Best, James