Pioneer SA - 1040 Amplifier Relay Not Clicking :(

Thread Starter

smarthawk

Joined Apr 24, 2020
29
Pioneer SA - 1040 Amplifier Relay Not Clicking :(

Hi all new to this forum hoping for some help with me trusty amp.
I bought this amplifier from Dubai where they have 220 Volts with 50Hz cycles, but i'm not moved back to Canada where it's 110V with 60Hz cycles electricity.The unit does have the voltage selector to select the voltage like 220V-240V and 110V-120V and i'm using 110V-120V.
For some reason when i turn on the unit, it turns ON with all the lights etc but it's the Speaker protection Relay is not Clicking (not completing the circuit to pass the current).

Is the because of the more Voltage Hz cycles as it was made to get 50Hz but here in Canada it's 60Hz or is the Relay unit itself which is now faulty for no reason all of the sudden ? I could be wrong but the unit was working perfectly fine in Dubai before i moved back.
I have attached the pictures of the circuit and the Relay as well as the the service manual with diagram.

Your time and help would be appreciated.
 

Attachments

Last edited by a moderator:

Dodgydave

Joined Jun 22, 2012
9,159
The speaker protection relay is powered through Q701 to Q706 transistors, which look at the Voltage across the speaker output, it should be zero volts compared to ground.

On page 9, 10 locate the relay and measure the Voltages at the changeover terminals, one channel must be faulty giving over 1.5V. The Power supply is a +/- 66V.
 

Thread Starter

smarthawk

Joined Apr 24, 2020
29
The speaker protection relay is powered through Q701 to Q706 transistors, which look at the Voltage across the speaker output, it should be zero volts compared to ground.

On page 9, 10 locate the relay and measure the Voltages at the changeover terminals, one channel must be faulty giving over 1.5V. The Power supply is a +/- 66V.
Hey DD,

Thanks for your suggestions, i'll look it up in the morning and update. cheers
 
The protection relay RL701 will not pull in if:
1. DC offset voltage is present at either channel amplifier output (senses at R713 or R3714).
2. Over-current for either amp output (Q710, Q702) - not likely with no speakers unless emitter resistor open, R591 or R592.
3. The 12V rail is not up (Q405).

I would turn the amp on and measure each channel's output voltage, say at R705 and R706.
If a channel is blown, there will be lots of DC not 0V and the protect relay will never pull in.
 

Thread Starter

smarthawk

Joined Apr 24, 2020
29
Hey,

Thanks for the input, how would i know if If a channel is blown, there is DC volt instead of 0V ? how about i replace R713, R714, Q710, A702 and R591, R592 and Q405 ? :(
 

Dodgydave

Joined Jun 22, 2012
9,159
You need to measure the Voltages at the Speaker outputs on the Relay contacts, to ground, there should be no voltage at the speaker outputs or less than 500mV,,.
 

bwilliams60

Joined Nov 18, 2012
1,312
Have you checked the voltages at the relay when you activate the system? I had one go bad on another Pioneer unit that I rebuilt. Not saying that is what it is but if the relay doesn't work, what are you seeing for voltages at the relay coil?
 
Top