Sansui 4000 "protector" light always on

[jeeem]

I recently rescued a Sansui 4000 from storage in my basement. I'd never opened it up before, but somebody had. (There's a little spring jerry-rigged to hold up the tuner indicator wires.) The first thing I noticed as I was about to do a little cleaning inside was that the PROTECTION lamp was hanging loose and appeared to be burned out. So, I replaced it -- but now it stays on all the time. (Not sure what the original bulb was, so I tried a couple.)

What is My Protector trying to tell me? I replaced the three fuses (R, L, main) accessible from the back of the unit (they didn't look blown, but I figured I might as well try it), but that didn't appear to accomplish anything.

Any ideas?

 

[dly66]

Two things come to mind. Protector circuit could be acting up or amp section has an issue. Keep in mind these were manufactured back in the early 1970s so would not be surprising a 50 year old piece of electronics may need repair.

The 4000 should be a very nice receiver (first hand experience with the 2000A and 3000A) and well worth fixing. This vintage Sansui very nice looking, sounding, and generally very solidly built. Looking at the service manual protector lamp is supposed to be 25V 90 ma bulb.

Actually that vintage Sansui the spring keeping the pointer power wires out of the way I do believe was standard. Seem to remember my 2000A having a spring there. Looking at web images of the inside of the 4000 the spring belongs there. Looks like it has the original gray Elna electrolytic caps you would expect of that vintage unit. Most of what I can see looks original.

 

[Dzemo71]

Hi
dly66 the "spring" is a standard it keeps the pointer wire not to be drug cross the board
Jeeem i am in possession of same receiver and i have same unresolved problem its true something is wrong since protector is acting but what i did couple day ago i did remove ground from protector block (probably protector got disabled)and i got the sound on the outputs back and everything works fine(so far) this is not something i recommend but you can try as first aid
Something is wrong on protector block or after block so whole purpose of protector is to keep whole system safe
Receiver old 40-50 yrs is normal something like this try this solution but consider to find right reason why protector is acting

 

[jeeem]

Hi
dly66 the "spring" is a standard it keeps the pointer wire not to be drug cross the board

Thanks -- I'd never encountered a spring like that before. I gave the whole inside a good cleaning (I invested in a rechargeable air blower) and DeOxited (is that a verb now?) the contacts and that seemed to do the trick. I have a Luxman L-430 that does something similar. The "warm-up" light stays on for a few minutes before the relay finally clicks in, so I'm going to open it up and give it a good cleaning today...

 

[Dzemo71]

The biggest problem that i experiencing now is that i cant remove a tuning knob the screw in the knob is stuck so i cant remove front panel to give proper cleaning and to change a couple bulbs
i`m afraid of damaging front plate so i decided no to touch knob again at least rest is all functional(except protector which is disabled) i will leave it for better days

 

[jeeem]

I had the same difficulty recently with my Sansui 777A. I wound up buying a precision left-handed/extractor drill bit set ... and it worked beautifully the first time. You drill out the head of the screw and then insert the extractor bit. Here's the one I got:

 

[Dzemo71]

That`s a good idea i my consider it in the future
thank you