VECTREX Power Switch Revealed

[Rolo]

I got a dead Vectrex on my desk. I quickly figured out a malfunctioning power switch, which seems to be quite common for that console. I think I've read about that a couple of times on different pages. The switch consists of a 10K potentiometer (volume) with a double power switch attached to the bottom of it. It's quite some work to get it out of the console, since its soldered onto the logic board (3 pins). And there are four wires leading to the switch. There is nut, which holds the potentiometer firmly connected with the housing.

 

What's inside the switch? Can it be repaired?

If you open the switch all kinds of parts fall out of it . On the picture you see the right order.

 

If you start to reassemble from the bottom side, it looks like this:

You can see the two contacts and all the parts which convert the rotary movement of the knob into an up & down movement of the contacts, including a spring ZONG.

The silver metal piece is moved left and right by a plastic nose of a submerged plastic disk inside the potentiometer, behind the half circular slot. The plastic nose should be between the two sides of the catch - you see?

 

If you'd be building up the switch from the other side, It would look like this:

With some practice the switch can be reassembled.

 

Unfortunately, in the case of my console, after reassembling, I only could switch on one time. Switching off blocked. I'm wondering, if there is a second plastic nose supposed to be on that plastic disk, for switching off. I did not want to disassemble a working switch of another console and have a look inside. Maybe I can figure out someday in the future.

 

Instead I ordered a replacement part, which seems to be fitting quite well. I'll report, when the part will be delivered. Maybe there are other people who are looking for such a spare switch, too. I could order some switches and dispatch. But let's wait for the switch to arrive first...

Best regards,

Rolo

 

Edited May 25, 2015 by Rolo

[fiddlepaddle]

Wholly cow, what a mess that is...

[jfmateos]

I am interested

[CRTGAMER]

I added a second power switch inline with the original power switch. A push button right on the same panel, power can now be turned off and on again without changing the volume. If your volume control still works, the secondary power switch could be another option.

[Rolo]

I owe you one. The ordered power switch is here. Original one and new one. Quite some differences:

The plastic axis must be shortened. The flat side can easily be cut with a file.

The mounting holes of the housing and the frame must be widened from 8 mm to 10 mm.

The thing still is not fitting . The potentiometer connections have a different spacing and I attached small cables:

 

Finally reassembled and soldered (the reset button also).

Don't forget the ground connection.

Number #3064046 reporting for duty.

Another family member is back home .

 

Unfortunately this potentiometer/switch is not, what I was hoping for. Of course, it can be made fit in, like I did, but this was not my original intention. I as looking for an already fitting spare part. Besides, the potentiometer is not logarithmic, which is not ideal for audio.

Well, in the end it's working, no need to complain...

 

Btw. does anybody have a number, how many Vectrex consoles were made back in the day?

 

Regards,

Rolo

 

Edited May 27, 2015 by Rolo

[e5frog]

Stumbled upon this looking for a discussion about the plastic knob.
I remember it was a pain getting it back together, I also took two images for next time as I have another one I need to check right now. I recall needing to take it apart more than once because it worked one way but then didn't click back. There's that black knob as can be seen in the first image that needs to be between the two metal pins of the little metal part and that it tend to move when trying to assemble so all of it fell apart.

I recall the problem wasn't anything in the latching part but the contact surfaces that needed a polish - so when finally getting it back together it worked and still is. I posted the images on some forum where I also described how I managed to do it finally - but I can't find it again. I think it mattered in which position the small plastic knob was when putting it back togeher or it jumped over or something and switch only worked one way. :-(



Maybe these will be of use to someone as it also shows the little plastic knob in the black plastic disc.

I'd probably put a switch on the powercord instead of trying a replacement if it was broken. Switch only cuts current after the transformer so if left "off" that way the transformer will still get warm. I recommend having it connected to an outlet with a switch so mains can be cut off as well.

[e5frog]

This could be a spare part:
http://www.ebay.it/itm/Lot-of-5-Matasushita-Electric-Panasonic-EVQBQ8K20-2D3R-TV-3-M21A-Power-Switch-/111864791744

It seems to be missing standard pins for the pot but the power switch seems similar with markings "2D3R TV-3"

Edited January 17, 2016 by e5frog

[vtk]

I'd probably put a switch on the powercord instead of trying a replacement if it was broken. Switch only cuts current after the transformer so if left "off" that way the transformer will still get warm. I recommend having it connected to an outlet with a switch so mains can be cut off as well.

 

i've noticed that too, my vectrex makes a hum sound even when powered off but plugged into the mains

 

maybe something like this would be a solution:

 

http://www.ebay.co.uk/itm/191566877282

[Rolo]

"Standby" power consumption wasn't an issue in the eighties. It's just a bit of parasitic energy consumption, due to iron losses. That will do no harm to the transformer. When installed, I let my Vectrex hum. Most of the time, I need the space on my table, I have to put it onto the closet anyway.

[e5frog]

Just successfully disassembled, fixed and re-assembled a switch. I see the white bow-tie looking part with the middle hole is positioned wrong in the images above, here's my evening in images:

Tear down Vectrex, cut or desolder red wires from switch. They are bent around the solder ears so it may be easier to cut the wire than trying to pry it out while heating it.
It's AC so I don't think you need to keep track of which wire from the transformer goes to which wire - but keep track of which ones go in and which ones go out. Switch breaks both lines of the cirka 20VAC - which is good as there's a center tap as well going directly to the power board (white wire).

You'll have the switch like this:


You can see four solder ears, two of them for output (large ones, C and F) and the smaller ones closer to eachother (A, D), we want to open the three pieces of bent metal that holds the black plastic to the metal cup, like so - should be no problem, I used a flat screw driver.


Now you can slowly pull the black plastic part out - the parts inside are spring loaded and will probably fall out and/or get dislocated, if you can open it in a plastic container or similar you don't have to crawl around on the floor looking for the parts later on.

When I pulled mine out I was left with this, the bow-tie shaped white plastic part with a hole may have fallen out the other parts are not loose and can't fall out (unless broken).


The reason it was still there was because some green colored grease had turned to a thick sticky clump and this was most likely the reason it wasn't working. Vecrex didn't turn on at all, then very very slowly off or on.
The white plastic part has a bow shaped edge on one side with a small small notch - that's pointing to the narrow steel pin end.

Here's the green sticky goo visible, the two metal parts that are supposed to be moving easily to and from the connector areas was also very hard to move, same type of grease most likely. The contact surfaces where also a bit work - from sparks most likely.

I degreased the plastic part, not it has round indentations on the back - the part facing the two metal parts, it's most likely important to get this in the proper direction as the little notch in the round cut out is only placed on one side, probably to keep it in the right place against the base of the side with the steel pin.

It was a lot of work getting the contact parts to move easily, 5-56 seemed to work best after trying alcohol, degreaser etc.

Here's the metal can, you can see three clamps inside holding the volume part against this one, note the important knob on the black plastic there in the bow shaped cut out. You also see the other parts there on the side, the three switch parts re-mounted the correct way.


Here's the spring, metal part and large brown part, mounted properly. There's wear on the metal part that gives away where the spring is supposed to go, the rest is pretty much clear after that.


After brusing the contact surfaces with a soft metal brush in the dremel I got nice clean surfaces - just a little, don't want to wear it down. Put some lithium grease on the white plastic part as well as the metal pin - that goes into the brown plastic part. White part goes with the rounded side to the metal pin (left in the image), the two recess round areas points down and is not visible here - even if there hadn't been grease on it. I tried to center it as well as I could.


With the black knob in the bow shaped cut out being in the same position as before - farthest it can go in that direction - I placed the mechanism over it. The fork like part of the metal part goes over the black plastic knob, the pin of the same metal part goes into the hole under the bow shaped cut out - important thing is that the black knob is inside the "fork" - it needs to stay there.


Time to put the lid back on... Aim for the bulge of the metal can, aim the bulge of the plastic there, put the metal pin in the hole of the brown plastic.


When effortlessly putting it there, keep closing carefully until you get the center knob of the brown plastic in the hole of the little white plastic part, keep closing, don't twist yet.


... posting a second part, no more images seem to be welcome here.

[e5frog]

Close all the way in like so:


Note that the plastic and metal can doesn't fit, all you have to do now is to carefully twist until they meet and push it closed.
Important thing now is to hold the bottom piece there while testing the switch that should click the same in both directions, if you loose the grip you'll have to do it all over again.

While holding bend the three metal pieces back - don't loose grip.
We get this:


... and it's fixed - possibly, unless you had broken parts. Greasing it up and cleaning contact surfaces should be enough if all parts are there.

I got 0.08 Ohm and 0.17Ohm on the two contacts, switch moves easily with a nice click.

 

 

I'm back to the laboratory for reassembly.

[e5frog]

 

i've noticed that too, my vectrex makes a hum sound even when powered off but plugged into the mains

 

maybe something like this would be a solution:

 

http://www.ebay.co.uk/itm/191566877282

It's probably the transformer although they are quite quiet on the Vectrex, heat is never a good thing so cutting power is a good idea. Even if mounting a switch on the cable solves the problem it's IMHO better to use a plug in switch or power strip - this is valuable antiques, let's not destroy them.

[e5frog]

Here's an example of another possible replacement:
http://www.maplin.co.uk/p/omeg-10k-andohm-linear-single-gang-potentiometer-with-switch-fw42v

It also has a linear tapered pot but I'm sure it would be possible to get a log pot from the same brand and swap parts.
Then there's the question about mounting the button, axle might need some modding.

[Rob Mitchell]

Thanks for your tutorial .. I may have to tackle this someday ..

[Nebulon]

Thanks everyone for posting these.

 

I think I'll put my Vectrex on a power bar while the switch still works (and I'll just use the dial for volume control).

[Maraakate]

This is a somewhat large bump, but what kind of grease did you reapply? I don't think white lithium grease is appropriate. But maybe the Dow Molykote stuff used in VCRs and other small plastic gears may be OK? Or is it simply dielectric grease?

[e5frog]

It depends on the type of plastic, not all of them "dislike" mineral oil and a lot of different types of lubricants are called "Lithium grease", all info we get from that is that it's grease and there's lithium in it or rather lithium oxide. If googling you'll find both answers.

You should probably go for a silicone based grease (such as Shin-Etsu G-40M or Molycote 44) if you want to play it safe.

[Maraakate]

Okay. Thanks for this. I figured it probably should be some lighter type of silicone grease. Lithium grease could possibly work, but it's very temperature dependent.

[EdwardianAge]

Excellent Vectrex Power switch - Volume control repair thread!

[gotcha]

One more Vectrex saved The details given about the power switch in this thread made the repair of the power-switch itself relatively easy. Thanks !

 

What I found more difficult was to get access to the power switch. It requires removing the logical board, what IMO is not very simple for the Vectrex.

[joedredd]

Hi, thanks to this post I decided to tackle the job myself.

 

I've made a video on YouTube that clearly explains how to service this switch for others.

 

You can see it here: https://youtu.be/VW8Rlx6f8ps

[Yoruk]

Thanks for sharing these pictures. I'll definitely try this on my switch.

[gorf68]

So if I were to bypass the switch to check that this is indeed the issue, would I connect the two outer legs to make it permanently on?

[Yoruk]

Yes, but I suggest to remove the switch first !

[gorf68]

On 8/17/2021 at 7:37 AM, Yoruk said:

Yes, but I suggest to remove the switch first !

Why?

 

If it's not connecting anyway, what difference does it make?