Hi Menahem

It's good to read your message

I still have that speed problem. At max + on 33.3rpm, it still runs about 3 to 5% slow. Although the belt is in reasonable condition, I will pick up another on Monday. I have not yet glued the motor pulley but I don't think there's any slippage. The 45rpm still runs considerably slower than 33.3rpm and when a 7- single is placed on the platter, the arm moves up to the platter's rim and that's it.

So this afternoon I started another session of work. First, I dismantled the speed indicator display and found the 1kOhm? linear pots almost  inaccessible so I did second best - used some contact cleaner and worked them from side to side and now it has some speed adjustment capability.

I reassembled everything and started work on the keypad. I removed the stainless surface plate and removed the board and found the up/down control jammed to continuity and fixed that. Then I found there were two of the multipin connector's wires hanging by 1 thread and fixed that.

While the stainless key surface was off, I decided to remove the finger wear marks.

I did this using a 3M sanding pad and discovered the surface was varnished. The finger wear marks were into the varnish. No problem, I mixed some automotive satin clearcoat and hardener and gave the plate a few light coats with an airbrush over the freshly sanded surface, restoring the surface as new.

So I re-assembled the control panel and all the current problems are still there  

I am not sure if any of the components on board 8(?) under the control pad could have a bearing on the the problem. I see there's a pot and capacitor there, as well as a relay.

I will check the thin pcb for touching solderpoints - I am alert to such errors but will doublecheck.

I think one can reasonably rule out the motor for speed difficulties. It runs silently and freely with no screws overtightened. And it is lubricated - as is the platter bearing. As I now have two dc motors (including the one with the rewound rotor) both (mis)behave similarly).

Question: Will it be possible to simulate the 2 motor speeds with a bench power supply with digital display? When I repaired the original motor, I tested it with 3Vdc + at the red wire and - at the centre blue, drawing 0.12A. If for example the same voltage is applied to + to the motor's white wire and - to the blue, the motor also runs clockwise but slower, drawing only 0.04A. I am writing now about the rewound motor. The motor in the turntable now is a motor which was given to me by a very kind US 4002 user. This motor was sent to me in pieces and as 'not working'. I re-assembled it and tidied up some bad soldering to its pcb and got it to work. Later this morning, I will double-check to see if the two motors behave similarly. 

The main pcb can also be ruled out as it was proved to be working correctly. All testing done the last few days is with the covers still not fitted properly, nor is the cover on the arm mechanism. There shouldn't be a problem with light confusing the issues as all covers are pushed close together to exclude light.

If the 33.3rpm arm function is correct in all respects, can one assume that the 45rpm arm operation will also be OK? I'm thinking specifically about the ruler's position (I marked its position) and or the positioning of the newly fitted LED?

My 4002's cover plates are in relatively good condition. Years ago, I fitted a mono switch (just bridging L+ and R+) but may revert to another plate from one of the 4000's which may have to be modified a little to fit.  These plates are a little dull and I may try the phosphoric trick on them. For the uninitiated, this could be dangerous but if I do it, I will post some safe directions for the not so fainthearted.

Regards all

dauphine/andre 

Hello Guys

Yes, I'm still around[:)

I have been working intermittently on the 4002 (and also been listening) quite a lot but that 45rpm speed issue has been with me for many weeks.

So, on Monday this week, a tech friend came to visit and we spent quite a few hours with my 'scope hooked up and eventually homed-in on the possible cause of the slow-running 45rpm speed.

The problem was the fine speed adjust 1kOhm linear potentiometer. For most of the time, the 45rpm speed was selectable (but running much slower than 33.3rpm) and a few days ago, I cleaned it in situ once more with a fine brush, a bit of compressed air and some contact cleaner.

Despite the careful work, the motor stopped running and on Monday this week - after my friend had left, I desoldered the part and dis-assembled it completely.

I immediately saw that the carbon track inside had disintegrated near each connecting pin and decided to try some Leitsilber L100 conducting silver paint to 're-connect' the pins to the carbon track.

I applied 3 coats with a fine brush around the corroded areas and let the paint dry before re-assembly. And it worked!

I now have 45rpm speed again.

I hope this experience helps the 4002 owners here.

As I had taken the 4002 completely apart again, I started re-assembly this evening.  Installing the cover plates is quite a job and required a bit of gentle tapping with a piece of hardwood to get the plates to fit.

After this job was done, I tried a record on the platter and...the arm would not drop

A million thoughts about possible causes later, I thought I'd visit here and look once more at pics I posted in this thread.

I think I found the cause of the problem. One of my pics clearly show there are TWO springs fitted near the arm mechanism, solenoid and damping cylinder.

The lefthand spring must have dislodged itself during re-fitting of the cover plates.

I have spare springs but I will HAVE to find the missing spring as it could be somewhere inside and could cause a short or interfere with the carriage transport.

Never a dull moment...

A fine weekend to you all.

andre/dauphine