I just opened up my Yamaha PX-3 to have a look inside and see if it was possible to lube the sledge. It seems to develop a few places where it gets stuck, properly just needs to get cleaned.

But it is not easy to get to this thing; more or less every thing has to be taken apart. So it has to be another day, a few pictures did come out of it.

See the black screws at the corners of the flat arm base? remove them and the whole shebang comes off. Leave the arm and rollers alone, since there is little to lubricate. Replace the square belt, Don't use a belt that is too tight!

My Transformer (see the GA6423) is defekt.
Yamaha say they dont got spares for this part.
So iam very unhappy about this.... :pity:
Is there otherwhere a chance to get this Part ?

Answer is also welcome via PM or mail
Many thanks !!

merrylander has recently gone through a PX-3 from end-to-end. He also has a spare parts machine, I believe. You might ask him. Good luck.

You also need to pull the arm toward the middle and disconnect the two cables. Then you can test the operation with a 9 volt battery across the red and white wires, reverse the polarity to change direction.

The transformer secondary is 40.8 volts center-tapped, at least that is what the service manual shows. That reading was presumably taken under normal load, so anything between 40 and 42 volts should do the trick.

When you get the arm out you will see two springs holding the wide belt together, they tend to have lost some tension and it is easy enough to add a bit by reforming the ends. Where the motor drives an intermediate shaft that in turn drives a roller that drives the wide belt the small square belts are usually pretty good. The roller does get polished and a bit of 200 grit paper makes all the difference. The whole arm assembly does ride on roller bearings that might just have dried grease in them.

My spare transformer has a 120 volt primary, would not help in your country.

Rob

PS: I would disconnect the one slate, two blue and two red wires and pull that transformer. Then I would pop it open and see what I might find. With nothing to lose it might turn out that the 'open' winding is a broken wire close to the surface.

Thanks a lot, @ Merrylander ! and @ Ymaha B-2 !!
i will do what u tell me,
be very shure !!
I dont wont to miss my Turntable !

Good Luck Marcus. I did not realize at first that there were two AK'ers looking at their PX-3s. You might also see if there is a transformer rewinding shop in your area.

markus-o: As long as it is not the chips that are fried I think you can get the PX- up and running again.

Yesterday Evening we changed the Transformer,
we take it out (proviosely from an Pre-Amp Yamaha C6) and put it into the PX-3
Works good so far.
but there was some more errors on the electronic Dish.
The 7819 (? dont remember the Number ) Brick from the 12 Volt Minus Power was also broken..
To anlayze it we have to open the brigdes from some parts on the dish.
In the beginning there was no Minus 12 Volt avialable..
We are still working on it.
A good old elctronic specialist is working on it.

I can point you at a source for the two big chips., one in England and one in Canada.

markus-o are you saying that the GA6423 also resides in the C-6?

GA6423
No,
its NOT in the C-6, Its GA-6298
its a bit different but got enough of Power..
But @ this time there a no new News right now.
I'am still waiting for my friend..
Also thanks @ Merryland for the big Chips,
i dont hope that they are complete broken !
But if there is no other way... THX

I just got through working on a PX-3 and in this case it was not responding to the switches. I took out the big board and sprayed Deoxit into all the switches. After three days it now responds to all the switches. Replacements for 6 of the TACT switches are obtainable but exact replacements for the 2 SPDT switches that move the arm are not. Those two switches move the arm slowly, then when you press harder they move the arm faster.

Yes,
my PX-3 :banana::D

The Transformer is now repaired !
My friend puts a new temperatur chip into :thmbsp:
So now we got the 40 Volt on the components.
The Chip needs only "one" repair for the Minus 12 Volt-Side..

@ Next we checked out the Belt, it was very loose,
we fix it by setting the screws in correct position,
and we changed the belt in direction, so that it will be run like new.
and we also fixed the roles.

Now the PX-3 works perfect !
Only one bad think, whitch i can not explain myself...

The System MC 1000 is broken, but why :wtf:
We disconnect it before we start working on the turntable..
We checked all cables, tommorrow i will verify this
and connect the PX-3 first time on my Denon DAP 2500.

I realy dont know where to get this System in "new" ?

Congrats Marcus!

Super markus.

The MC 1000, are you refering to the chartidge? What is wrong with it, broken how?

Was it mounted while you worked on the TT?

And nice pics.

Was it mounted while you worked on the TT?
No it wasnt :confused:

But the Turntable was out of home in a mechanical-Store bevore we start this litle Work-Around... :D
with the System on the Turntable,
i think that was my fault, perhaps somebody destroy it....
But it was needed,
because it was importend for the insurance, we need in germany a paper from an officiell dealer....
So,
he wrote me a document, that the PX-3 is not possible to be repaired...
I remember that i had paid min 250 € for the MC 1000 in the past
(must be some Years ago..)

What is wrong with it, broken how?
Very Simple:
There is no Signal .... No Sounds anyway...

Tommorow i will watch for it...

And nice pics.
Yeah,
my House and a friend of mine, the fantastic Electric-Man,
old man good man :bigok:

It might be possible to repair if it really is broken, but try it on another TT and phono stage.

If you need a new cart, the AT-OC9 seems to be on sale all over at about half the list price. That one I think would be quite similar to the MC-1000, I have the older MC-1x but I think it needs a retip so it is bit hard to compare it with my AT-OC10.

but try it on another TT and phono stage
Yes i did it this morning !
All is working fine :banana:
I'am very happy :beerchug:

I have the older MC-1x
This one was mounted also on my turntable many years ago,
then a dog (from a friend of mine)
crashed the system in not realy one second...
"increndible"

The MC 1000
I remember a price anything around 250 € :tears:

btw:
Thanks for your support !

Yes the MC-1000 was 255€, sold from 1984-1992.
The MC-1x was 250€, from 1979-1983.

The price might be a little insecure due to Dollar/D-mark/Euro translation.

BTW. nice repair.