After delving into electronics basics, I’ve returned to troubleshooting my Pioneer Av Amp, which is experiencing power-on problems. Apologies for the delay in revisiting this, but I’m now focusing on diagnosing and hopefully resolving the issue.
My initial step was to address the capacitors on the primary power rail. Four capacitors were inspected, and while one appeared potentially problematic, replacing all of them with new, high-quality capacitors didn’t resolve the core issue, though it’s good preventative maintenance.
Next, I conducted voltage tests on the 9-pin connector. The readings were as follows:
- Pin 5 CPU_+3.3v: 3.29v
- Pin 6 CPU_ST_VCC: 10.24v
- Pin 9 CPU_ST_VCC: 10.24v
However, these readings changed when the amp was powered on (after multiple attempts). Pin 6 and 9 dropped to 7.04V, while Pin 5 increased to 5.02v. Furthermore, measuring voltage on pin 7 relative to negative pin 4 showed 12.1mV when off and 32.0mV when on.
Suspecting a relay issue due to the need for multiple button presses to power on, I decided to replace the RLY301 relay. The original JZC-36FD relay was replaced with an SDT-S-105DMR, chosen for its similar specifications. The thought was that even if the original relay was clicking, it might be failing to make consistent contact, causing the intermittent power-on behavior.
Unfortunately, replacing the relay did not fix the problem. I still encounter the same issue with powering on the Pioneer AV amp.
Voltage measurements on two of the relay pins show 10.13v, which, to my understanding, seems to be within the expected range for relay operation.
To rule out a simple user interface issue, I proceeded to clean the front panel buttons, ensuring no sticky or unresponsive buttons were contributing to the problem.
Despite all these steps – capacitor replacement, relay swap, and button cleaning – the Pioneer AV amp still exhibits the same power-on difficulty.
I attempted a system reset by holding down the Power and Band buttons simultaneously, but this was unsuccessful. Since the amp requires multiple power button presses to turn on, the reset procedure, which likely requires a stable power state, couldn’t be initiated.
At this point, I’m beginning to suspect a more complex issue, potentially involving a microchip failure within the Pioneer AV amplifier’s control circuitry.
What are your thoughts on this diagnosis? Any further suggestions for troubleshooting steps or specific components to investigate within this Pioneer AV amp would be greatly appreciated as I continue my search for a solution. Thank you again for any help you can provide.
