hifi engine

Can power switch be repaired?

I have a Pioneer SA-8800 integrated amplifier that I had poster here about the power switch having gone bad. It started as a flickering power lamp and I could hear a crackling sound, to where it wouldn't latch at all.
I found a replacement on eBay, but am now thinking that that replacement is also 30+ years old.
So I'm wondering, can my original power switch be repaired?

Re: Can power switch be repaired?

Probably not. Once there is arcing at the contacts it is pretty much fried. If you have an ohmmeter you can test the 'new' switch; should read 0 ohm. if there is any fluctuation you might try spraying some contact cleaner inside then actuating the switch several times.

Re: Can power switch be repaired?

Thanks. So looking at worst case, where this switch also fails and I can't find a replacement, can a 'generic' switch be installed? Would I need to alter the faceplate to make it fit?

Re: Can power switch be repaired?

Depending on the type of power switch it is on some rare occasions the switch can be repaired. But usually it needs to be replaced. Some of these old/vintage units' use a DPST or DPDT switch and only uses one side of the switch & can be rewired to use the originally unused side of the switch. I don't know if yours is one of these.

When/If you try to clean the switch with DeOxit or another contact cleaner. You MUST UNPLUG the unit BEFORE cleaning the switch. And BEFORE you plug it back in you MUST let the switch dry. Which WILL take a while. Will help if you can blow out the switch with air after cleaning.

As for your 30yr old replacement switch.

First you need to/must replace the snubber capacitor that is across the switch contacts (this helps prevent arching of the contacts) with a NEW one.

Next you can modify the circuit by installing a power relay controlled by your replacement switch. With your replacement switch only turning on & off a relay & the relay actually powering the unit, it greatly reduces the load & stress on your possibly irreplaceable switch & make it last a lot longer. A relay is much easier to find a replacement for.

I would do anything possible so as NOT modify (re: RUIN/DESTROY) a faceplate and/or case/chassis. Even if it means leaving the old switch in place but disconnected, bypassing it & use an external switch to turn on/off the unit. Be it a plug bar/power strip with a switch on it or getting a single plug-in switch.

Re: Can power switch be repaired?

I have used different switches and it's usually a pain. The knobs won't line up correctly so they bind. If the switch is soldered to a circuit board then mounted to a bracket it is sometimes possible to alter the position of bracket, but it's a lot of work to get it right.