Signa Solo -- No sound
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platinum95
Posts: 1
My Signa Solo (about 2 years old) stopped outputting sound suddenly. Had no issues with it up to this point. Looks like it's the same issue seen in a few other posts here.
I've checked with multiple input sources, same issue persists. The LEDs come on and the device appears to operate as normal (including automatic source-switching depending on source activity), just with no sound.
I hooked a UART interface up to the UART pins on the rear of the device, and the status messages sent by the main MCU don't indicate any problems; for example, the following is the UART output on startup, switched to Bluetooth input.
I went a bit further with the debugging and took the device apart to try narrow down the problem. The Bluetooth module is functioning fine, and it's outputting a valid I2S signal which is passed through to the DSP's SPDIF input. The analogue input makes its way to the ADC, at which point the ADC doesn't output any I2S signal as it's not receiving the clock signal from the DSP (the DSP isn't outputting any clock signal, just a stable 3.3v level).
I checked the SPI lines between the DSP and its ROM (used by the DSP during bootloading), and saw that it was loading something up at boot, so there's at least some life in the DSP. Next I checked the I2C line between the DSP and the main MCU. The MCU is attempting to send messages to the DSP, however the DSP is not pulling the SDA line low for the ACK bit so the MCU gives up (though doesn't print anything helpful to the UART interface).
I thought that maybe the DSP was having trouble sinking the SDA line low, so I tested out adding a 10k resistor between SDA and GND to try brute-force the initialisation. This did cause the ACK bit to be registered by the MCU, but there's still no sound.
I checked the other usual suspects: power rails are fine (5v for the ADC, 3.3V for the MCU, and 3.3V & 1.8V for and DSP). The RSTOUT pin of the DSP (i.e. the error-indicator) is high, so it's not reporting that anything's wrong. Fault lines from the amps are high too, so no reported problem there.
I had hoped that the DSP was just dead, so I got a replacement (had to go with a D2-92683 as the 92684 can't be purchased in single quantities anywhere) but the exact same problem persists.
At this point, I'm stumped. The DSP is clearly not responding to the I2C comms from the MCU, though I'm not sure why. Possibly waiting on some other state during bootup?
I really don't want to have to throw this whole thing out, that's such a waste! Especially if there's only a single component on the board that's burnt out. Ideally I could just buy a replacement board, but I couldn't find any parts for sale by Polk, which sucks.
I've checked with multiple input sources, same issue persists. The LEDs come on and the device appears to operate as normal (including automatic source-switching depending on source activity), just with no sound.
I hooked a UART interface up to the UART pins on the rear of the device, and the status messages sent by the main MCU don't indicate any problems; for example, the following is the UART output on startup, switched to Bluetooth input.
power on Pair D2 init amp ok conn
I went a bit further with the debugging and took the device apart to try narrow down the problem. The Bluetooth module is functioning fine, and it's outputting a valid I2S signal which is passed through to the DSP's SPDIF input. The analogue input makes its way to the ADC, at which point the ADC doesn't output any I2S signal as it's not receiving the clock signal from the DSP (the DSP isn't outputting any clock signal, just a stable 3.3v level).
I checked the SPI lines between the DSP and its ROM (used by the DSP during bootloading), and saw that it was loading something up at boot, so there's at least some life in the DSP. Next I checked the I2C line between the DSP and the main MCU. The MCU is attempting to send messages to the DSP, however the DSP is not pulling the SDA line low for the ACK bit so the MCU gives up (though doesn't print anything helpful to the UART interface).
I thought that maybe the DSP was having trouble sinking the SDA line low, so I tested out adding a 10k resistor between SDA and GND to try brute-force the initialisation. This did cause the ACK bit to be registered by the MCU, but there's still no sound.
I checked the other usual suspects: power rails are fine (5v for the ADC, 3.3V for the MCU, and 3.3V & 1.8V for and DSP). The RSTOUT pin of the DSP (i.e. the error-indicator) is high, so it's not reporting that anything's wrong. Fault lines from the amps are high too, so no reported problem there.
I had hoped that the DSP was just dead, so I got a replacement (had to go with a D2-92683 as the 92684 can't be purchased in single quantities anywhere) but the exact same problem persists.
At this point, I'm stumped. The DSP is clearly not responding to the I2C comms from the MCU, though I'm not sure why. Possibly waiting on some other state during bootup?
I really don't want to have to throw this whole thing out, that's such a waste! Especially if there's only a single component on the board that's burnt out. Ideally I could just buy a replacement board, but I couldn't find any parts for sale by Polk, which sucks.
Post edited by platinum95 on
Comments
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You repair it?
