Maxpower
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- Jan 31, 2025
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TLDR: All the amplifiers in my Marantz SR8015 AVR would unexpectedly shut off, but the Video and all other operations would continue to work normally. I tear down the unit and replace the broken parts plus the bitter pill I must swallow.
I have added additional text after the pics for others who might be experiencing the same fault or for the technically curious.
What you start with
Where you need to be: there were many screws . . .
Four Layers Deep: the target Power/Speaker board is at the very bottom (of course).
(see notes at the end regarding a possible alternative removal method)
All the boards: eight PCBs plus the Power/Speaker board
The broken Parts: the bridge rectifiers are screwed down to a heatsink that is bonded to the chassis base
Remove the parts: cut the legs off the bridge rectifiers and use pliers to pull the pins through the PCB
Installed upgraded parts: the metal contact plate is the upgrade here. I assume the original items die a heat death or are simply not up to the task.
The new items have improved current, thermal and PIV
Add silicon thermal paste for improved heat transfer (also applied to the other items on the heatsink)
ECO Relay: factory relay placement
ECO Relay alternative overlays: Marantz Engineers gave us a Plan B, which may be needed in future.
Provision is made for the additional back EMF diode and driver transistor for a second relay
Re-assemble everything, smoke test it and then reinstall it into your system
Bonus Footage: The Great DAC mystery
Yes, the later model SR8015’s uses the Burr Brown PCM5102A chips. This is a bitter pill for me. I specifically wanted the AKM DAC chipsets for their native DSD capabilities. I did not realise at the time of purchase that Marantz had substituted these critical parts in the wake of the AKM Factory fire <sigh>
If anyone is interested, I can also post the before / after DAC PCB redesign. It was a significant undertaking.
Backstory / What to do?
Unfortunately for me, my unit was 3 weeks out of warranty and the (excellent) retailer I purchased it from 3 years ago recently closed their doors. On the upside, I have nothing to lose doing it myself . . . so come along on the journey with me.
The fault: can be reliably replicated with some small variation in the timing of the fault.
All amplified channels cease working but the pre-outs are unaffected; a simple power cycle generally restores operation. The issue occurs when the built-in power manager (ECO Mode) detects a volume level of 50 or above where it switches a higher AC supply voltage to the DC power supply. The fault occurs within a few seconds / minutes of this transition.
The ECO function works to reduce heat and energy consumption at lower volumes by reducing the available power to the amplifiers (ECO ‘On’ or ‘Auto’).
Recovery: it is sometimes possible to recover the amplified channels without a power cycle by manually switching the ECO Mode to ‘On’. Manually setting ECO to ‘Auto’ or ‘Off’ never recovers the fault.
Work around: Permanently set the power-on ECO Mode to ‘On’. The unit functions without fault but you will progressively hear audio distortion as volume is increased due to the lower voltage power rails available to the amps. The distortion is not subtle.
Diagnosis: There are two bridge rectifiers that supply power to the amps; One for low volume levels, the other for higher volumes. It is this second bridge rectifier that is most likely the issue, failing to deliver any current to the power amps after a short interval. Anecdotally, there are numerous internet reports of this issue on Marantz SR units, including reports from authorised Marantz workshops. The factory bridge rectifier is identified as the cause.
There is a third component in play. The ECO relay that switches the transformer secondary voltages to each bridge rectifier. This relay always responds to manual and auto commands, so there are no concerns with the relay control side. However, the contacts for the higher voltage switch pair may have become unreliable. It’s a no-brainer to proactively replace this part considering the disassembly effort.
Solution: Replace and upgrade the two bridge rectifiers. Replace the ECO relay.
Outcome: The unit is back in service now and I can happily report the issue is resolved. Let’s see how it goes with longer heat soaking and real-world use.
Other/Future options: the factory ECO relay choice stacks up on paper but the engineers at Marantz left their options open on the PCB layout to accept a more substantial relay, or two relays. This relay upgrade may be an option if there are any further issues.
The tear down experience: Despite the technical fault, I was impressed with the build quality and materials used in this unit. Add in the white glove, built in Japan halo (Shirakawa Audio works), plus the attention to design and workmanship . . . I feel my money was well spent here.
If you want to do this too: Be patient and allow for two, 4-hour work sessions at a minimum. Break up the fatigue and keep your concentration sharp, you’ll need it. ESD / Static management is an absolute must during the repairs (ESD mats and body earthing), take many photos, use ESD plastic pry tools wherever possible, post your wins / fails!
Alternative removal method: It may be possible to extract the PCB stack as one big module. I did consider this as the rear panel metal work is removable. I chose not to guess and avoid wasting time only to find there was single inaccessible screw or connector that could not be reached. Please share if you have any experience with this.
I have added additional text after the pics for others who might be experiencing the same fault or for the technically curious.
What you start with
Where you need to be: there were many screws . . .
Four Layers Deep: the target Power/Speaker board is at the very bottom (of course).
(see notes at the end regarding a possible alternative removal method)
All the boards: eight PCBs plus the Power/Speaker board
The broken Parts: the bridge rectifiers are screwed down to a heatsink that is bonded to the chassis base
Remove the parts: cut the legs off the bridge rectifiers and use pliers to pull the pins through the PCB
Installed upgraded parts: the metal contact plate is the upgrade here. I assume the original items die a heat death or are simply not up to the task.
The new items have improved current, thermal and PIV
Add silicon thermal paste for improved heat transfer (also applied to the other items on the heatsink)
ECO Relay: factory relay placement
ECO Relay alternative overlays: Marantz Engineers gave us a Plan B, which may be needed in future.
Provision is made for the additional back EMF diode and driver transistor for a second relay
Re-assemble everything, smoke test it and then reinstall it into your system
Bonus Footage: The Great DAC mystery
Yes, the later model SR8015’s uses the Burr Brown PCM5102A chips. This is a bitter pill for me. I specifically wanted the AKM DAC chipsets for their native DSD capabilities. I did not realise at the time of purchase that Marantz had substituted these critical parts in the wake of the AKM Factory fire <sigh>
If anyone is interested, I can also post the before / after DAC PCB redesign. It was a significant undertaking.
Backstory / What to do?
Unfortunately for me, my unit was 3 weeks out of warranty and the (excellent) retailer I purchased it from 3 years ago recently closed their doors. On the upside, I have nothing to lose doing it myself . . . so come along on the journey with me.
The fault: can be reliably replicated with some small variation in the timing of the fault.
All amplified channels cease working but the pre-outs are unaffected; a simple power cycle generally restores operation. The issue occurs when the built-in power manager (ECO Mode) detects a volume level of 50 or above where it switches a higher AC supply voltage to the DC power supply. The fault occurs within a few seconds / minutes of this transition.
The ECO function works to reduce heat and energy consumption at lower volumes by reducing the available power to the amplifiers (ECO ‘On’ or ‘Auto’).
Recovery: it is sometimes possible to recover the amplified channels without a power cycle by manually switching the ECO Mode to ‘On’. Manually setting ECO to ‘Auto’ or ‘Off’ never recovers the fault.
Work around: Permanently set the power-on ECO Mode to ‘On’. The unit functions without fault but you will progressively hear audio distortion as volume is increased due to the lower voltage power rails available to the amps. The distortion is not subtle.
Diagnosis: There are two bridge rectifiers that supply power to the amps; One for low volume levels, the other for higher volumes. It is this second bridge rectifier that is most likely the issue, failing to deliver any current to the power amps after a short interval. Anecdotally, there are numerous internet reports of this issue on Marantz SR units, including reports from authorised Marantz workshops. The factory bridge rectifier is identified as the cause.
There is a third component in play. The ECO relay that switches the transformer secondary voltages to each bridge rectifier. This relay always responds to manual and auto commands, so there are no concerns with the relay control side. However, the contacts for the higher voltage switch pair may have become unreliable. It’s a no-brainer to proactively replace this part considering the disassembly effort.
Solution: Replace and upgrade the two bridge rectifiers. Replace the ECO relay.
Outcome: The unit is back in service now and I can happily report the issue is resolved. Let’s see how it goes with longer heat soaking and real-world use.
Other/Future options: the factory ECO relay choice stacks up on paper but the engineers at Marantz left their options open on the PCB layout to accept a more substantial relay, or two relays. This relay upgrade may be an option if there are any further issues.
The tear down experience: Despite the technical fault, I was impressed with the build quality and materials used in this unit. Add in the white glove, built in Japan halo (Shirakawa Audio works), plus the attention to design and workmanship . . . I feel my money was well spent here.
If you want to do this too: Be patient and allow for two, 4-hour work sessions at a minimum. Break up the fatigue and keep your concentration sharp, you’ll need it. ESD / Static management is an absolute must during the repairs (ESD mats and body earthing), take many photos, use ESD plastic pry tools wherever possible, post your wins / fails!
Alternative removal method: It may be possible to extract the PCB stack as one big module. I did consider this as the rear panel metal work is removable. I chose not to guess and avoid wasting time only to find there was single inaccessible screw or connector that could not be reached. Please share if you have any experience with this.
).
