Repair: Sanyo RD XM1

March 7, 2020 

Just a foreword before you start reading this page, work on this is currently at a standstill. I am currently quite busy and have a lot of devices in use with minor problems, I would like to have these working again before I continue on this. The intention was to deliver this page only when it was completely ready. Now that we are a few months further without any progress, I think it is time to make this page public. When I finally get around to the Sanyo RD XM1 I will supplement this page.

The Sanyo RD-XM1, a rather rare example in the HiFi world, for all logical reasons.

The Microcassette was mainly used for recording voice messages; voicemails, memos or entire conversations between two people.

Because the tape is quite small compared to a normal cassette, less tape fits on it. In order to get a longer recording time, these tapes are played very slowly. As a result, a lot of sound quality is lost, but that does not matter much with voice recordings, as long as it can be understood.

Nevertheless, in the early 80s an attempt was made to bring this medium into the music world, the RD XM1 is the result.

The latest version of noise reduction (Dolby HX) and tapes with metal tape, together this should meet the sound quality again. In theory it wouldn't have been a bad idea, but in practice it was very disappointing.

The modern gadgets were not enough to boost the quality and since the compact cassette was already firmly present on the market, it remained with this model.

Now that we've roughly gone through the history of the device, let's rewind to the day I received the device.

September 10, 2019 I received the device, firmly packed in a thick cardboard box.

After unpacking, I stare at another box, this time the original packaging.

Inside, the device is securely wrapped in Styrofoam, a cardboard sleeve and another foil bag.

The device has never been used and comes new out of the box, a time capsule from the early 1980s!

Here is a short video I made on the same day.
The sound quality on this video is quite poor because I'm playing it through a cheap speaker. I'm playing here a part of the demo tape that comes with the device.

Surprisingly, the device still plays well for its age. But it took me a while to get it going. The straps have been in the same position for a long time and have molded to it, although the device plays, it is necessary to replace the straps if I want to get a good quality out of it.

Belts are not easy to find for this device, in the end it took me a few weeks to find the right belts, now I was still looking for the courage to get started.

Anyone who knows my website a little, probably also knows the videos of 'Techmoan'. I myself got a lot of inspiration from his videos, I also know the Sanyo RD XM1 through him.

In his video he says that changing the belts would not be an easy task, despite my interest I was discouraged by this. Only to buy a unit a few years later when I got the chance.

Now it is not courage that I seek, but challenge!

I've had the belts for several months now, but today I have a free afternoon and have nothing planned. Time to finally get started!

But before we start, I remind the reader again that I am going to tinker with an electrical device, during testing the housing is open and there is voltage on the device, there is also a chance that you will damage the device or its cables with electrocution hazard.

In short, only follow my steps if you are sure of your actions and have the necessary knowledge. My actions are no guarantee for a better future of your audio equipment...

Grocery list: 

  • Phillips head screwdrivers (PH1 & PH2)
  • nippers (small)
  • Locking pliers (small)
  • Fine locking pliers
  • Tweezers (large & small)
  • Awls X2 (preferably curved)
  • Cotton swabs
  • Ketonatus (96% Alcohol)
  • Ty-raps (small)
  • Tray for screws
  • New belts
  • test band
  • Have we not forgotten anything?

Of all the fixed devices in the collection, this is the smallest on which I can play and record music. It is crammed with parts, lots of screws and especially cables that are not going to make it easy for me. Time to disassemble it.

[Concept from this point, look for possibility of filming disassembly]

On the back and sides there are a total of 7 black screws, they are the only ones that have a coating and are therefore easy to distinguish from the rest.

There are black washers under the screws, with me they were glued to the frame but come off easily with some picking.

I'm currently using the PH1 crosshead.

It sure is compact! Heavy too, the weight is in the transformer you see at the top left. We're going to look at the running gear.

Seen from above, you can see two belts running, the one coming off the small engine (green arrow) and the flywheel belt (red arrow).

There's a third belt just out of the picture that drives the tick counter, we'll see it later. For now, let's move on to the disassembly. The entire running gear has to come out of the housing and that is only possible if almost all other parts are loose!

The frame is next, there are 3 screws on the top and 3 on the bottom. They are recessed (have a slanted head), this is how you can recognize them.

There are also filler pieces hidden underneath. These are loose, remove them before they fall into the device. 

The frame can be detached, but not taken off. The incoming sound button stops it. I've searched for a long time but haven't found a way to release this button yet. I recommend that you leave the frame attached otherwise, it probably doesn't have to come loose....

The door window has to come out. It is secured with two special screws. With my bent awls I can unscrew them without damaging them. They are quite conspicuous and therefore easy to recognize among the other screws.

Be careful with the window, it is prone to scratches. Place it out of reach of your work area, best on a soft surface.

You are now left with the metal housing of the door.

There is still a metal part of the housing under the frame, which also comes loose.

For this we continue on the left side, three screws that can be removed, the two that are circled in red, also hold another small circuit board, which also comes loose.

Two more screws to the right.

Continue with the bottom, again three screws that can be removed.

There are two more screws on top, when these are also removed, the front is separate from the housing, these two hold the running gear and must be loosened whether you want to remove the front or not.

The circuit board must be loose, it is secured with four screws, these have insulated rings that are fragile, be careful with it and put these special screws separately.

Let's take a peek under the circuit board, it's a tangle of cables! On the back is the connection for a wired remote control. I don't believe it was ever released.

There are several plugs on the underside of the PCB. I remove as much as possible to get freedom of movement.

Two small plugs on the bottom, you can't get them off easily because you have to be careful not to destroy anything.

On the left side of the circuit board are two more plugs, these are clicked into place but can also be disconnected. There are also a lot of cable ties, I can't get these loose, so cut as much as possible in the end. I'll be replacing them with new Ty-raps soon.

We take a look at all the screws, there are now a lot of them.

To be continued...