The power of my Pioneer SA 9500 amplifier will come on but the speaker protection relay will not click.The + and - dc of the power supply are normal.The voltage at the E B C of the output transistors are the same between the L and R channels. At the suggestions of the EXPERT, I took out all of the output transistors from the heat sink.4 n p n and 4 p n p. Carefully line them up so each one will go back in the same location.None of the transistors are either short or leaky.The reading of the transistors between the L and the R channels are the same.And I did took out the relay and energized it with the 24V.external power supply the relay did responses with positive clicking.Can anyone out there take me to the components on the " Over-current and over-load detection circuit " or "Relay driving circuit." Or something else ???. Please HELP.
Is the dc voltage reading on the base of the outputs 0.6 with emitters reading 0.014 or there about. Depending on the outputs used you might read 1.2volts on the base. Your collectors will read the power supply voltage of 50 or 60volts or more. If this is what you are reading on your meter the problem is in the speaker protection circuit. This circuit is what drives the relay you tested.
SOURCE: Won't stay on even in standby
The voltages are wrong. You should see (0.0, +/-0.6, and B+/B-) on the 3 pins. The driver section has a problem. Check the driver stage for shorted transistors or open resistors.
Dan
SOURCE: i have a yamaha amplifier in here for repairs, the
Measure DC to ground on the output transistors to check for any offset. The protect circuit is the least likely to be the problem. Post the readings here and I'll guide you from there.
Dan
SOURCE: i have a pioneer surround amp, about 10 years old,
Disconnect the speakers and try it again. Come back with results. It's trying to tell you there's a short on a speaker output.
SOURCE: DC Offsets on output - protection don't allowd to switch on
you don't want to do this( bypass the protection0
that d.c. output will burn the coils in your speakers with out making a sound!! you have a biasing problem
or like you said a d.c. offset problem it is best to work on this problem with out a load on the amp, this will allow you to trace back where the trouble is starting at. caps will cause this sort of problem but leaky transistors can also do this, even diodes.
this will require an experienced trouble-shooter.
The Lifestyle
stereo amplifier is designed for use with Bose non-powered environmental speakers or
Bose non-powered accessory speakers ONLY
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