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Power Switch?

F

farr out

Active Member
I have a 4900z that is in great cosmetic shape and is very clean inside. I picked it up because this was my first "real" receiver back in the early 80's and I always regretted getting rid of it. It works great except for one thing: When first powered up the lights flicker and it distorts until it settles down. Then all is well. I "fixed" this by using an inline power switch and leaving the unit's power switch in the on position all the time. If it powers on fine with the inline switch the problem has to be with the unit's power switch, correct? I am just wondering if this rules out something like the power supply or relays, etc. Thanks in advance, Scott
 
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With Pioneer defective power switches can cause the sort of problems you are having, no reason to believe Sansui is any different. Is this a sperate power switch or is it part of the speaker switch? If the latter that's bad news, if a seperate push button switch you should be able to find a replacement at DigiKey.
 
Sounds like it's just the switch.

Most switches can be disassembled for cleaning. Worth a shot. If you bust it, it needed replacing any way.:yes:

It may be tricky.

I agree, you should be able to find a replacement switch.

Rob
 
Some of these switches are double pole switches with just one pole used. I forget offhand if the 9090 is that way. If it is, you can switch the leads to the unused pole and then you have fresh, unused contacts and should be good to go.

Also, if the switch has failed electrically, be sure to replace the capacitor that is usually placed across the switch contacts. It may have failed and caused excessive arcing that damaged the contacts.

- Pete
 
LBPete said:
Some of these switches are double pole switches with just one pole used. I forget offhand if the 9090 is that way. If it is, you can switch the leads to the unused pole and then you have fresh, unused contacts and should be good to go.



- Pete
Click to expand...

This is what I did for the failing Power Switch on my Realistic STA-2100D and everything works as it should now. Twas a real pain in the arse to get to though.
 
OK, got a good look at the switch and resoldered a resistor that looked iffy on the board the switch is on. Thought I might have it, but when I fired it up it did the same thing. The transformer makes noise while the unit is trying to fully "boot up". It can't be the transformer can it, cuz like I said in my earlier post when I had it on an inline switch it was always fine? Should I try to replace the switch (looks like a lot of fun!)? Thanks for all your help, I'm trying to learn as I go along, and appreciate your patience.
 
You can just by pass the switch as a test. Use a power strip to turn it on and off. At least that way you will know if the switch is the problem. There are several reasons Transformers will make noise. What you are describing sounds like it is under a lot of electrical load. So you may have other troubles.

- Pete
 
LBPete said:
You can just by pass the switch as a test. Use a power strip to turn it on and off. At least that way you will know if the switch is the problem. There are several reasons Transformers will make noise. What you are describing sounds like it is under a lot of electrical load. So you may have other troubles.

- Pete
Click to expand...

When the unit finally quits complaining the transformer quits making the noise. I think I will just remove the switch and order a new one. Do I simply desolder the switch from the board its on? If I can get it out I will post a pic of it for identification. Thanks.
 
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