Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Repair I couldn't turn down.

Nigel Goodwin

Super Moderator
Most Helpful Member
I don't really do repairs any more, but when an old friend's daughter contacted us we couldn't turn it down :D

As you can see, the selector switch is dangling - as I removed it. It had obviously had a bang on the front of the knob, as the rear of the switch was displaced, I pushed it back in place, but it still doesn't feel right - so I've ordered a new switch.

IMG_0249.JPG
IMG_0250.JPG
 

Reloadron

Well-Known Member
Most Helpful Member
Classic hand wired chassis. Love how looking at the component layout you can see each channel of the stereo.

Ron
 

AnalogKid

Well-Known Member
Most Helpful Member
The busbar wiring in the middle and the flying diodes over the caps in the lower left corner take me back -

Back in the early 70's when I was in school and building a TV station, part of it was hand-building some 24 Vdc, 10 A linear power supplies on 3U and 4 U rack panels (public TV station, no money to buy commercial units). Control transformer, big black diamond bridge, and large "computer grade" electrolytic caps. The wiring was open frame using #10 bus bar in what we called "refinery wiring" - exactly as in this amp. Lovely.

ak
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I've pulled plenty of those switches apart and never seen springs like that in them.
Must admit, neither have I? - anyway, I've removed the spurious spring, and fitted the new switch - all inputs now work (on a buzz test), got to bring a phono to 3.5mm jack lead in tomorrow to stick some audio through it.

The faulty switch by the way is made by Alpha, and I can't see any kind of spring to operate a detent mechanism, so perhaps that was the spring?.

Just had a close look - there's a hole right through the switch shaft (inside the body), that spring must go through the hole, and have a ball bearing at each end?.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I think I've got one or two faulty ones in the shed I can pull apart and check.
Not the best of pictures, you can't see the detents in the body - but I've slid the spring in the hole in the shaft, and if you push it right in it's about flush with both sides, ideal for a ball bearing either end to sit in the detents.

20220608_083815.jpg


BTW, it's playing AC/DC at the moment :D
 

Latest threads

New Articles From Microcontroller Tips

Top