All,
I am working on a Denon AVR-1513 exhibiting some strange behaviour. The receiver works normally, except for these two.
1. All three protect relays (FR, FL, C, SR/SL) energize immediately when the power switch is pressed. There is no delay. The light flashes green during (as if there was a delay) and then becomes solid.
2. The receiver does not "lock" onto HDMI sources (PCM icon and HDMI icon are flashing intermittently). Analog sources work just fine. After a few seconds of trying to lock on the receiver goes into protect mode
Findings.
1. Voltages at the speaker outputs are all normal. Voltages at the bias adjust test points are 2.5mv +- .5 mv.
2. Sound quality is good from non-HDMI digital sources and analog sources.
3. HDMI output (i.e. Menu screens etc.) look good.
4. The receive does not report any errors in service mode.
Note:
1. Lots of floating grounds in this receiver. MCU has a floating ground, as does the analog pre-/power amp sections. When checking voltages you have to reference the correct ground or your readings will be erroneous.
ikonw8
I am working on a Denon AVR-1513 exhibiting some strange behaviour. The receiver works normally, except for these two.
1. All three protect relays (FR, FL, C, SR/SL) energize immediately when the power switch is pressed. There is no delay. The light flashes green during (as if there was a delay) and then becomes solid.
2. The receiver does not "lock" onto HDMI sources (PCM icon and HDMI icon are flashing intermittently). Analog sources work just fine. After a few seconds of trying to lock on the receiver goes into protect mode
Findings.
1. Voltages at the speaker outputs are all normal. Voltages at the bias adjust test points are 2.5mv +- .5 mv.
2. Sound quality is good from non-HDMI digital sources and analog sources.
3. HDMI output (i.e. Menu screens etc.) look good.
4. The receive does not report any errors in service mode.
Note:
1. Lots of floating grounds in this receiver. MCU has a floating ground, as does the analog pre-/power amp sections. When checking voltages you have to reference the correct ground or your readings will be erroneous.
ikonw8
Check you #1 (speaker DC) at the connector from the amp board to the power/protection board - before the relays. You are nothing at speaker outputs because the relays are tripped.
I would guess you have one or more DC conditions, it’s going into protection for a reason.
I would guess you have one or more DC conditions, it’s going into protection for a reason.
Thanks. Checked the DC on the board before the relays, and I am getting 2.5mv. The MCU is supply the right signals to instruct the relays to go at the right time.
All the relays turn on as soon as the receiver is turned on. Including the headphone relay. Very strange. Thinking it is a ground or supply issue since all the relays are coming on at the same time, and not waiting for the MCU to tell them to turn on.
All the relays turn on as soon as the receiver is turned on. Including the headphone relay. Very strange. Thinking it is a ground or supply issue since all the relays are coming on at the same time, and not waiting for the MCU to tell them to turn on.
I figured it out.
1. The HDMI intermittent fault was a solder blob that was not quite bridging a trace carrying data to DGND. Cleaning that up resolved the issue.
2. The relays turning on when the receiver is power up (immediately - no delay) was tougher to figure out. It ended up being a broken pad on the connector from the digital board to the main board. The pad had a hairline crack on the relay signal from the CPU. Cleaning up the pad and resoldering it fixed it.
Note: grounding is very important on this unit. Nearly all the grounds are floating, and not tied to the chassis.
1. The HDMI intermittent fault was a solder blob that was not quite bridging a trace carrying data to DGND. Cleaning that up resolved the issue.
2. The relays turning on when the receiver is power up (immediately - no delay) was tougher to figure out. It ended up being a broken pad on the connector from the digital board to the main board. The pad had a hairline crack on the relay signal from the CPU. Cleaning up the pad and resoldering it fixed it.
Note: grounding is very important on this unit. Nearly all the grounds are floating, and not tied to the chassis.