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SVT standby toggle switch

slap5string

slap5string

Jul 19, 2010
373
3
Cleveland, Ohio
#1
How difficult is it to replace the standby switch on a 73 SVT? I noticed this switch beginning to go bad a few weeks back, then last night when I fired the amp up, it came to life with the standby on! I tried to switch the standby off then on again but it just flicks and doesnt grab or have any positive weight behind it.
 
#3
B-string said:
Not hard at all, but care must be taken as it is in the high voltage path. ;)
Click to expand...

If I remove the screws from the bottom - that tray should just slide out - no? Im hoping the switch will be easy to get to at that point. Is there a specific type or rating for the switch I need to be aware of? I was thinking about swapping the polarity switch from the front with the deffective one since my amp was modded with a 3-prong cord, but after looking at it, that switch on the front may be a be-atch to get at.
 
#4
Some Deoxit D5 might get that old switch working like new again.

35681397-260x260-0-0_Caig+Caig+Deoxit+D5+Spray+Contact+Cleaner+Rejuvena.jpg
 
#9
T-Bird said:
Hi.



Yeah, a good way to set Your amp and home/rehearsal space on fire :rollno:.

Never, ever try to "fix" a malfunctioning mains voltage switch with fuel.

Regards
Sam
Click to expand...

The Deoxit D5 front label clearly states "WARNING: FLAMMIBLE"...
If you or anyone else doesn't fully understand the ramifications of that warning, you should not use this product.

In the OP's situation, I'd suggest unplugging the amp and discharging the caps first, then follow all the safety directions printed on the back of the can.

I still think there's a very good chance the OP's standby switch could be cleaned/lubed to work for several more years. Its probably just hanging up because its lubricating grease has dried up.
 
#10
I use the 100% D100L Invalid Link Removed with the needle applicator. Because there is no propellant, it is non flammable. It is also less wasteful than the spray.

Some of these type of toggle switches have tabs that can be bent out and the switch disassembled for cleaning and repair. I try to fix it first but if the switch is well worn, I replace it. If you can get a drop inside, it can work wonders. Sometimes you want to keep things all original so repair or replacement with an original part is the only option.

 
#11
Funny thing is - about 2 weeks ago I turned the jam nut that holds the switch on and the switch started working as if it wasnt broken. But as you can see, it Im having problems again. Maybe ill have some luck with the cleaner. Any chance I can get some of this inside the switch without taking the amp apart? :)
 
#12
It really depends on the switch. Some are sealed and are a one piece molded plastic. Some can be opened. That doesn't guarantee that it can be fixed. The older SVT's had the standby on the power amp chassis. This makes it easier, the originals were a long bat switch, similar to the type that you can get from a hardware store. There's a lot of room to fit it in. It might be easiest for you to simply replace the switch.

The standby switch below is from an early SVT and it has a single piece molded body and is sealed. Not the type that can be easily fixed.


The switch below is the type that can be opened. The tabs connected to the metal sides can be bent back, the metal frame removed, which reveals the inside. The Deoxit is then used to clean the contacts.

 
#13
slap5string said:
Any chance I can get some of this inside the switch without taking the amp apart? :)
Click to expand...

I've done it, I just position the amp so the toggle is pointing upward, then slowly-spray/drip the cleaner into the circular gap where the toggle-lever enters the switch. The sprays pressure/gravity will carry the cleaner inside. Keep working the switch back and forth to help the cleaner work, then more cleaner and repeat if necessary.

For switches, I like using the D5 formula because it contains lube to help keep the switch from getting stuck/hanging up like yours is doing now. My radio shack stocks cans of aerosol D5 formula. (ps: when spraying into that switch, you should prolly wear eye protection...)
 
#14
Ok - I've ordered the relacement standby switch from Fliptops (thanks for the link B-String!) Now my next
question is: What is the best way to dias-assemble in order to get at this switch? I've never taken this amp apart before and though I'm somewhat mechanically inclined, I'd hate to remove too much if there is a more direct way of going about this. I'm sure there are some of you out there who have done this repair at least once (probably many times for you techies) and any advice would be extremely helpful. The amp has been unplugged from the wall for over a week now, so I'm hoping all high voltage has dissepated by now. Thanks Guys!
 

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