Here's the first step on the road to recovery:

Lubrication of ALL these points is incredibly important.

If the arm does not lower (barring any severe electrical problem), the cause is dried/coagulated lubricant on the RED circled areas.

If you can see any dried grease, remove it. 

Then gently squirt Sewing Machine oil onto:

1. Both ends of the Yellow Solenoid Piston (Thick and Thin parts)

2. The Piston of the Copper Damper

3. The Axle pivot connecting the Solenoid and Damper

I had to replace the 1N4004 Diode, so I used a high-speed UF4007 - this also helped to solve the problem with the arm not lowering at the correct point, when starting to play an LP.

I also replaced the 22nF Capacitor with a Panasonic Polypropylene unit.

This absolutely solved the "Arm not Lowering" problem 

I also converted the Photoresistor bulb to a White high-intensity 3.0V LED and a 1K resistor (see post below).  This is by no means necessary, but it's one less thing (burnt-out bulb) to have to worry about in the long run.

The next problem to solve was this 33/45 Speed problem, which is more detailed in this post:

Now that I had the machine working physically, I naturally wanted to listen to some LP's.

So I put on one of my CD4 Quad LP's, and ended up with this problem:

Then, I got challenged again with this problem, which Mika in Finland helped me, by solving the problem before I had to deal with it.

The last problem (I hope) I had to deal with, was the 33 and 45 indicator lamps heating up, and burning/deforming their plastic housings.

I am a fan of LED's, primarily because of their long-life, cool operation, and highly-directional intensity, even though the associated resistor warms up while killing excess voltage.

And I also know that some purists on this forum object to the use of LED's - and that's OK. I respect their opinions, and I have learnt a lot from them!

Anyway, this LED upgrade works beautifully, and does so without adversely affecting the required voltages on the Flip-Flop circuit (called a "Vienna-Bridge" in the Service Manual). I had feared that it does affect the voltages, but further testing shows that all is OK.

In the picture, on the white plastic hinged shields, you can see the yellowish damage, due to heat emitted by the standard incandescent lamps.

Parts required (total cost less than $1)

2 x Yellow LED's 1.8V,  Intensity >10,000mcd

1 x 1000 Ohm, 1 Watt metal film resistor

Some heat-shrink tubing.

Current to illuminate the 33/45 Speed lights is supplied by the Red wire. 

The voltage present on the Red wire is 22.8VDC positive, which has to be reduced to about 2 Volts.

I chose a 1 Watt resistor (1/2 Watt would normally be enough), because the resistor carries the excess voltage, and heats up. Using a 1 Watt resistor, results in a much cooler resistor.

I unsoldered the Red wire from the PCB, and soldered one end of the resistor in its place.

I soldered the other end of the resistor to the Red wire.

I placed the resistor at a small distance from the white plastic housing (around the metal bolt), to eliminate the possiblity of heat damage.

The LED's must be sanded lightly to give an opaque appearance, to distribute the light evenly.

I marked the -ve lead of the LED with a blue marker, which you can see faintly on the upper edge of the LED. If the LED's polarity is incorrect, it will not illuminate.

In the picture, the LED's upper conductor is -ve, and the lower is +ve.

20 minutes work, and a great result!

yachadm wrote:

I also converted the Photoresistor bulb to a Yellow low-intensity 1.8V LED and a 1K resistor.  This is by no means necessary, but it's one less thing (burnt-out bulb) to have to worry about in the long run.

I have the LED and the resistance. How exactly do I do this work? My knowlodge about electronics is very low level. Where do I put the 1k resistor. On one filament of the led?

Thanx

Hi Loris,

I don't want to discourage you, but this is not a simple job, if you are not very comfortable with a soldering iron,  and if you can't read a basic circuit-diagram - there is too much room for error, and likely destruction of the turntable.

IIRC, the resistor should replace the existing one on the PCB, and the LED must be wired the correct way, or it will not work.

On my previous post on this page, I specified a 3V LED - I'm not sure from where you got the above clipping about a 1.8V LED.

If you use a 1.8V LED which is not suitable with the 1KOhm resistor - your 1.8V LED will burn out. On this circuit, the LED must be a 3V LED to work with a 1KOhm resistor, to not be damaged.

If you haven't got a friend/technician who can help you, I would much rather that you sent this beautiful turntable to Dillen in Denmark - he is one of our most technical members, with an excellent workshop, and he will restore this for you, with much more than just the LED upgrade.

Regards

Menahem.

yachadm wrote:

I also converted the Photoresistor bulb to a Yellow low-intensity 1.8V LED and a 1K resistor.  This is by no means necessary, but it's one less thing (burnt-out bulb) to have to worry about in the long run.

I read about the led here, in the second post. Well actually I didn't write I was telling about the photorestor lamp in the carriage, and not about the arm lamp.🙂

Is this an easier work to do?

Loris

ps anyway I was thinking about sending all do Dillen. I only have to gather some money for the shipments and the repair....🙂