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Pioneer Sx780 not working AC power problems.

Carlkits

Carlkits

Member
Hello my friends.

My pioneer Sx780 doesn't work in my apartment.

I found the receiver in mint condition, not been put in work for the last 30 years.
I take it to a repair shop and comes home with the relay clicking.

I tested for hours in my office, in the repair shop and even on the underground garage of my building worked very well, but I test in several different outlets inside my apartment and there's no way to use without the relay clicking.
Thanks to #merlynski I'm troubleshooting and I'm planning to do a recap.
Gonna replace some caps e the follow:

"Low voltage or poor quality power can be a problem!"

It's seems bad lucky, the receiver works like a charm, but not inside my house.
 
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petehall347 said:
be best to test your AC power ..and also try the 780 in the office again .. i take it you are using same speakers ?
Click to expand...
Hello Pete, I use 3 different pairs of speakers, and the repair shop put the receiver at full power and worked for 6 straight hours without any kind os troubles.
I used for another 6 hours today and worked like it was 1978 fresh out of the store.
But in my home, I just plug in the outlet and the relay starts to click.
 
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I also have a Sx626 with problems in the left channel, but that unit doesn't have a relay, I wonder if the wiring damaged others receivers on the house.
 
Did you measure the AC voltage at your outlet in your apartment? That is the first thing to do. There is no point in doing any work on the unit until the power in your apartment is fixed and verified good, as there is no way to test the SX-780 to see if anything else you did was done right or wrong.
 
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merlynski said:
Did you measure the AC voltage at your outlet in your apartment? That is the first thing to do. There is no point in doing any work on the unit until the power in your apartment is fixed and verified good, as there is no way to test the SX-780 to see if anything else you did was do right or wrong.
Click to expand...
I schedule a certified technician to go check the wiring of my apartment and the main electric box of the building.
I'm a civil engineer, good with concrete, but I'm really gonna make a effort to learn my ways to repair my vintages gears.
 
Measure the AC voltage coming out of the socket in the wall, post your measurement:
Are you supposed to have 220vac or 240vac voltage at your location?
 
merlynski said:
Measure the AC voltage coming out of the socket in the wall, post your measurement:
Are you supposed to have 220vac or 240vac voltage at your location?
Click to expand...
Here in Brazil we have 127vac or 220vac.
We used to have 110vac, but now only the 2 above.
In my region I only have 220vac, so I use one transformer to reduce to 127 vac.
But I use that same transformer in the repair shop, and worked fine.
I bought a line filter with dps to try stabilize the energy, I also have a nobreak 115vac that I'm thinking about tested on my receiver.
 
I would think it’s really low (The voltage) if it causes issues.
It wound be similar to using a varic to limit the voltage. Probably works but fails when you increase the volume?
 
A professional electrician suggest to change the circuits breakers and install grounding dedicated to the receiver.
But the Pioneer Sx780 doesn't have grounding in the power cable.
 
zebulon1 said:
I would think it’s really low (The voltage) if it causes issues.
It wound be similar to using a varic to limit the voltage. Probably works but fails when you increase the volume?
Click to expand...
zebulon1 said:
I would think it’s really low (The voltage) if it causes issues.
It wound be similar to using a varic to limit the voltage. Probably works but fails when you increase the volume?
Click to expand...

Hello

I tested voltage and seems working fine, gonna replace the circuit brakes, they are from 1997,and maybe rewired one outlet exclusively to the receiver.
And the clicking happens even without the speakers connected.
With the new dps line filter the receiver is working with less clicking, but still does.
 
Carlkits said:
AC from the socket on the wall : 222 vac
Ac from the reducer of voltage : 122
Click to expand...
Those numbers look OK.

Carlkits said:
A professional electrician suggest to change the circuits breakers and install grounding dedicated to the receiver.
But the Pioneer Sx780 doesn't have grounding in the power cable.
Click to expand...

The SX-780 was designed without a hard earth ground on the chassis, and IMO it is not a good idea to add one through the power cable.
Do you have any other connections to the SX-780? Does it still click when it is not connected to any other equipment?
 
merlynski said:
Those numbers look OK.



The SX-780 was designed without a hard earth ground on the chassis, and IMO it is not a good idea to add one through the power cable.
Do you have any other connections to the SX-780? Does it still click when it is not connected to any other equipment?
Click to expand...

I didn't use the outlets in the back of the receiver, I only connect to the reducer and the reducer is connect to the dps filter, who is connect to the outlet in the wall.

If I just plug in the outlet, with nothing connect to it, still clicks .
 
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