• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Sanyo Plus 75 Power Switch Fix!

dc270

dc270

Now Off the Reservation
I am not real sure where this belongs, but being a vintage unit I guess here is as good as any! As I have read there are several comments from people about the power switch/ button sticking or just not working. Oddly enough my unit had the same problem! I wanted to offer a little help for those willing or wanting to repair the problem.

As you would expect you take off the two side panels and metal top. I would next recommend you carefully remove the metal face. You can pull the two large knobs and next smaller round knobs straight off. The rectangular function select knob will need a hex wrench to loosen its set screw. Remove the 5 Phillips screws and the face comes loose.

Facing the front, on the lower left side, burred low in front of the power supply. is a 2" x 3.5" PC board with the power switch located on it!. This little PC board is held in place with two screws. At this point you have an couple of options. You can work on this power switch board in place- if you are very nimble, or remove the board and work on it farther removed from the surrounding clutter- which was my choice! You may have to cut a tie strap here and there, or un-screw a ground screw. Remember where it was to re-secure it.

The power switch is coupled to the actual front power button with a 3+" long, crooked, dark plastic arm. It is a two piece switch. It is press fitted into the short power shaft and can be pulled apart with a pry of a screw driver- don't get rough, it will pry apart. Before doing this I did remove the 4 screws that held the power supply in place and the laid the power supply on top of the metal heat sinks....carefully. Now that I had plenty of room behind the switch board, I could pry the power switch short stem from the extension arm from the power button. Once those two items are separated, I can now move the power switch board around easier. On top of the actual power switch there is an orange plate with glue dabs holding it to the top of the actual switch. Take an Xacto knife and trim away the glue holding the the orange plate in places. I took a solder tip and partially melted the glue as well. Once the glue is weakened, then you can take a small tip screw driver and gently pry up around the orange switch cover to expose the internal switch mechanism. I soaked mine down with DOxit over night, cleaned it up the following day and all worked perfectly!

On re-assembly, I had to re-screw the power switch board back in place with the two screws, then gently persuade the power switch arm into place onto the end of the power switch, then push the two pieces snapping them back together. This is tricky but do-able. This is why you remove the face plate, so you have room here to maneuver!

If you can work on the actual switch in place, then more power to you!. It was way to tight for me. I also did not break the switch apart as the over night soaking did the trick.While I was in there, some of the wire twists on the boards pegs felt loose, so I put a dab of solder on them to better hold them tight. I put it all back together and it worked like a champ.....the first time too!

While this is not an easy task, it is possible with patience and attention to detail. It is much better that an switch that buzzes or fails all together! This Sanyo Plus unit IS worth salvaging!
DC
 
Last edited:
Register to hide this ad
Deoxit will only be a temporary fix at best. You will at least have to polish/sand the contacts.

Check out this method, I think it is the same switch.
 
I'm also thinking that's a temporary fix at best as well. I had my non working switch apart and did the deoxit also and it did not help it. Luckily I happened to have the same 6 prong switch in my switch collection and swapped it out. Good as new. The 75 plus is a damn fine receiver and well worth going the extra distance imo.
 
you really need to physically take the switch apart to look at the contacts and the switch housing . if contacts are burned it is finished for switching mains power supply . if not contacts can be burnished so long as the plating isn't broken through it should be ok ..if switch housing is melted it needs a new switch for sure .
 
My main intent way the actual procedures needed to locate and access the switch itself. As for the actual switch repair- if possible- that can be another kettle of fish. You opted to the point of the switch dismantling and cleaning, which I understand. In my case I have usually found The Gold DeOxit to be a good contact cleaner as well, which is one of it's intended uses, so I applied it as such. IF in fact over a reasonable amount of time (say 2 or more yeas) it starts failing again, I my have found a replacement switch by then.
Thanks non the less for your input, it is another valid point.
DC
 
i have found if a switch was ok then the unit was stored and then started playing up a good deoxit treatment or similar is fine ..
if it has been arcing for a good while it will be burned and no amount of cleaning will be a long term fix . .
sometimes just leaving the switch in the on position and using a power strip to turn it on and off is best whilst waiting for a new switch ..
 
petehall347 said:
i have found if a switch was ok then the unit was stored and then started playing up a good deoxit treatment or similar is fine ..
if it has been arcing for a good while it will be burned and no amount of cleaning will be a long term fix . .
sometimes just leaving the switch in the on position and using a power strip to turn it on and off is best whilst waiting for a new switch ..
Click to expand...

I have no illusion the switch, will one day, burn out and fail all together and then need replacing. I now have the experience needed to to get to the switch, and if more people wants to service their switch, them above are the procedures one might well appreciate- along with your advice!
DC
 
dc270 said:
My main intent way the actual procedures needed to locate and access the switch itself. As for the actual switch repair- if possible- that can be another kettle of fish. You opted to the point of the switch dismantling and cleaning, which I understand. In my case I have usually found The Gold DeOxit to be a good contact cleaner as well, which is one of it's intended uses, so I applied it as such. IF in fact over a reasonable amount of time (say 2 or more yeas) it starts failing again, I my have found a replacement switch by then.
Thanks non the less for your input, it is another valid point.
DC
Click to expand...
My bet is on less than 2 years, maybe even less than 2 weeks. It depends on how badly it has been arcing. Deoxit can clean contacts but it is usually more than just a bit of oxidation in a bad power switch. The arcing may have pitted the contact and the plating of the contacts. The residue/lube from deoxit can even make the problem worse as you add a bit of resistance between the contacts, which can cause more arching.

Some people will sand the contacts down, which will work a lot better. But I think once the plating is gone from the contact nothing you do will bring it to 100%.

I'd opted for replacement of the contacts, I managed to do it with parts from a new easily available switch.
You can also make the switch trigger a triac, like in this thread. I'm going to try it in a pioneer 650 with a bad switch.
http://audiokarma.org/forums/index....orth-5-and-an-hour-or-so-of-your-time.504673/
 
You must log in or register to reply here.
Back
Top Bottom