looking for Power Switch in G-22000 / G-33000 (power amp section)

[ymarko]

The switch is broken. It’s quite small toggle switch that, I believe, should have 2 positions – Remote (On) and Off. It’s on board F-2905 pages 21 and 23 of G-22k/G-33k service manual.

It’s a small switch, I see it has 6 pins and 4 legs. Here are some pictures.
Photos 1 and 2 are from the net, showing how the switch should look in Off and Remote positions.

Photos 3, 4, and 5 are actual photos of broken switch (last photo is the back side, where pins are).

Could please electronic people lead me to the replacement switch?

Knob is missing too. Maybe someone knows the source of a similar-looking knob.

 

[LBPete]

I replaced one of those switches once but I don't remember the specifics. I got a small toggle switch from somewhere. I don't remember it being that difficult to find. It's a simple single pole double throw switch. Just find one that fits the space.

- Pete

 

[AUD101]

Also try the Sansui-Parts Shop in the Netherlands - They have NOS parts including various switches etc - Good-luck with your search

 

[jdurbin1]

I believe I have a small mountain of those switches... but there are different configurations. Looks like a three position DP switch that I should be able to match but I believe there are variants on that too, in terms of what connects in the three positions.

Take a look at the sides of the metal housing, LMK if you see any markings. Or, pull the switch and measure the contacts in the three positions. Need to know if it has a center off function where the outer pairs are disconnected from center and each other.

John

P.S. Here's a pic for reference, these are missing the metal cap but I have a bunch that still have it, cap looks just like the ones in the pics from the web.

 

[ymarko]

Indeed, this is a very small switch. Footprint on board (without pins) ~11mm wide x 17-18mm high. And it's about 12.5mm tall.

I'm not sure if it's 2- or 3-position switch. It marks Remote and Off, so maybe only 2 positions. There's some schematic on page 21 of service manual, but I cannot read schematics.

Part List on page 23 only says Main Power Switch, stock # 1171970. I did search and got nothing.

I shimmed the switch in On position w/ 2 pieces of toothpicks, see photo, but I didn't try to plug it On yet, not sure if it's Ok or not.

Your photo above is very similar to this switch.
I will open the switch again, and read its marks and measure the contacts.
Thank you.

 

[jdurbin1]

That's about right for these, other than this original switch has flanges that extend out at the top where mine don't. Body of mine is around 24mm but that encloses the mounting screw holes rather than having flanges sticking out, probably going to fit the same. The width is same 11mm, height is the same 12.5mm, handle style is the same (silver brushed aluminum), pretty sure the pinout will be the same other than question on electrical function.

Measure the spacing on the legs on the corners of the body that mount it to the PCB, also the on-center spacing across the mounting screw holes. I think those will match too.

These switches were made by multiple vendors including Tyco, Alco, and Alps. The ones in the pictures are Alps, but I have boxes of the same switch from Alco and possibly Tyco as well. Not as sure how many of the variants I have i.e. whether 2-pos or 3-pos, center off or other config etc. I know where they all are stashed though, so get those other details and I'll be able to confirm whether I have one or not. Available for cost of mailing if I do.

John

 

[EchoWars]

Just an FYI that I didn't see mentioned...this switch does NOT carry much current (I could dig out the schematics to see, but Imma not gonna. Prolly less than 50mA). Nearly anything you can find to replace it will suffice as far as current-carrying capability.

 

[jdurbin1]

Yeah, these are light-duty slide/toggle design... I ran across them while looking for replacements for the FM de-emphasis switch on the Tandberg 3000-series tuners. Turns out they use them on the preamps for cart loading switches too.

Not going to handle much power but I am sure that Sansui application is low-current switching, probably controls a relay or the voltage that controls a relay.

John

 

[jdurbin1]

Here's two of the three types I have:

One is a 3-pos w/center off (the one with the toggle centered) and the other is DPDT 2-pos. The 2-pos switch handle centers when it isn't in the position shown. I suspect that one is the replacement for this Sansui part.

I also have these in 4PDT 2-pos, might be some other variants in a bigger box I haven't gone through yet. The body dimensions and handle style are the same on all.

John

 

[ymarko]

Hi Jdurbin,

I disassembled and did some measurements on the switch board. Here's my sketch.

4 legs on the board are about 11.5 mm x 16 mm.
Then there are 6 pins in the middle about 5.5 mm x 5.5 mm.

I'm sure that these pins (and maybe even legs) could be adjusted a little to accommodate board holes.

The height of switch is about 15 mm.

The distance between 2 mounting screws is about 18 mm.

I am pretty positive that it is 2-position switch; both positions illustrated on my photos above, namely "Remote" and "Off".

Do you think one of your switch will fit? Thank you for your help.

 

[jdurbin1]

Yes, I believe so. The pins are an exact match, 5.5mm front to back and side to side. No solder pad changes required for those.

The width of the four mounting legs is also same, 11mm. But, these are spaced 20mm apart the long way where your drawing shows them at 16mm.

The on/off part electrically is a match as is the handle style.

If you want to try one, drop me a mailing address via PM.

John

 

[ymarko]

I'm glad to report that broken switch was replaced and new switch works perfect and looks absolutely as original.

I'm very grateful to John (jdurbin) for helping me out, finding and sending a free switch that matches almost perfectly, only minor adjustment needed.

This was not easy project; a lot of micro-surgery; old switch was attached to the board in 10 points. Had to work very carefully and need an extra hand or two. Had to made dozens of small decisions. But final result is worth it.

Here're a couple of pictures.
1st photo - new switch attached to the board.
2nd photo - old switch and new switch.

Thank you John.

 

[JOMARK911]

I"m glad you sort this out.

 

[jdurbin1]

Very cool. Glad to see one of these switches go to good use!

John