Volume problem with Marantz M-CR612
- Thread starter Schreurs
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- m-cr612 marantz volume problem
I too had this exact problem and contacted Denon customer services last week. They acknowledged it was a known problem and as the unit was not long out of warranty they would sanction a repair by Sontec Electronics in Norfolk. I had to pay to get the unit to them but it is being sent back to me today free of charge. They have replaced the power supply, hopefully with an upgraded model that wont fail after two years as the first one did. Can't complain about service though.
Thanks, I replaced capacitor C222 and added the new resistor and the problem with volume is now fixed.
info@ketanph
New Member
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pepeenriquez
New Member
Hi,
I share my experience here just in case it is useful to anyone. I own a M-CR612 since 2020, in Sept 2022 it failed with the volume problem and I sent it to the official technical service in Madrid for repair (this thread did not exist yet). They told me that it was a power supply issue, charged me 150€ and solved it. So far so good.
But in may 2024 the problem appears again, exactly the same. In the meantime the technical service of Marantz in Madrid has changed, so I send it to the new tech service to see what they say, and they answer with a repair offer for 300€ to change most of the inner PCBs, but, surprisingly, not the power PCB. I obviously declined.
Finally I discovered this thread (a bit too late for me, but nevertheless ...). I took apart the receiver and found out that in the original repair they changed the capacitors C222 and C223 with others with higher value (470 uF instead of 220 uF), which apparently solved the issue temporarily, but now the power supply is unable to deliver the -12V output, even when I changed back the capacitors and included the resistor R233 as in the diagram shared by RwinRT.
So I ended up buying another SMPS here: https://spares2repair.co.uk/denon-marantz-power-supply-board-smps-pcb-assembly-mcr612-n-k-mz21-046. This new SMPS comes with the new capacitor and resistance as in the service revision update diagram, as you can see in the image. And my receiver is working again.
So for me this shows that marantz has managed this "known issue" somewhat sloppily. It is almost impossible find information on the problem (excepting this thread), and their official technical service in Spain is none the wiser. And it also shows the lousy technical service marantz's partners is offering, at least in Spain.
So thanks to the contributors in this threads, which helped me solve the issue when I was almost giving up on finding a solution.
I share my experience here just in case it is useful to anyone. I own a M-CR612 since 2020, in Sept 2022 it failed with the volume problem and I sent it to the official technical service in Madrid for repair (this thread did not exist yet). They told me that it was a power supply issue, charged me 150€ and solved it. So far so good.
But in may 2024 the problem appears again, exactly the same. In the meantime the technical service of Marantz in Madrid has changed, so I send it to the new tech service to see what they say, and they answer with a repair offer for 300€ to change most of the inner PCBs, but, surprisingly, not the power PCB. I obviously declined.
Finally I discovered this thread (a bit too late for me, but nevertheless ...). I took apart the receiver and found out that in the original repair they changed the capacitors C222 and C223 with others with higher value (470 uF instead of 220 uF), which apparently solved the issue temporarily, but now the power supply is unable to deliver the -12V output, even when I changed back the capacitors and included the resistor R233 as in the diagram shared by RwinRT.
So I ended up buying another SMPS here: https://spares2repair.co.uk/denon-marantz-power-supply-board-smps-pcb-assembly-mcr612-n-k-mz21-046. This new SMPS comes with the new capacitor and resistance as in the service revision update diagram, as you can see in the image. And my receiver is working again.
So for me this shows that marantz has managed this "known issue" somewhat sloppily. It is almost impossible find information on the problem (excepting this thread), and their official technical service in Spain is none the wiser. And it also shows the lousy technical service marantz's partners is offering, at least in Spain.
So thanks to the contributors in this threads, which helped me solve the issue when I was almost giving up on finding a solution.
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After some while and some extra investigation, it turned out I needed to replace some extra components as the issue was not fixed.
so below I summed up the components needed replacement. Turns out the that if the volume stops working the -12v coming from the powerboard is missing.
C222: Old value: 220uF 35V > New value: 220uF 50V
R233: parallel to C222 an additional resistor of 470K needs to be placed.
IC223: 79L12 replaced by 7912. Mount 45 degrees backwards, as otherwise the body will touch the CD bracket.
Q223: LMBT222ALT1G (see att. datasheet) replaced with BC337 as I didn't have an SMD NPN 40v 0,6A available. The BC337 is 45v 0,8A. Please take notice of the pin-out and change in package, as the BC is TO-92 and the LMBT is SOT-23. Make sure you connect the leads correctly according B-C-E.
C221: 470uF 35V Replaced precaution wise as this was out of range.
Attached I added a small manual with more details.
Changes and modification at own risk. If you are not experienced on doing this, I hope I could be of help to the ones who will do the repairs eventually.
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Thanks for this! I was about to throw it in the trash, but your fix worked out well for me!
info@ketanph
New Member
Important!! Hi guys , I had a similar issue after just 3 years of purchase. The seller {a Audio visual shop owner and a repair centre told me that it was beyond repair} was totally uncooperative as it was out of warranty suggesting it was misuse. Unhappy with this the diagnostics I threatened the shop owner with court action in the Small Claims Court under the Consumers Rights Act 2015. {You will have to read up on this} I started proceedings and than came across this forum. I took this information back to the repair centre about what parts are likely causing the volume issue. With your detail diagram he was able to replace the 2 capacitors and got it working again. It has now been over 3 months and working fine. Your comment gave me the proof that this is a common fault and thus it is covered under this act { an expensive electrical item such as this it should last a reasonable length of time, and it is the sellers responsibility to get it repaired, offer a replacement or a refund}. I am happy to say that today at the court hearing, { which only lasted 10 mins} I and was awarded repair costs Court fees and loss of wages due to the absence from work in order to attend this hearing and travelling costs. Note: you have 6 years from the date of purchase to make your claim even if you have already had it repaired.
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info@ketanph
New Member
Thanks to you I got my unit repaired and got back the cost of it and court costs. See comment at the end
I have what appears to be the same problem with the sound on my M-CR612 - the sound is no longer responsive to the controllers. It seems to me that, since this is a known problem with at least many of the units from Marantz, that the problem stems from defective component(s) installed during manufacture. Even though my failure occurred around 4.7 years after purchase, I hope that Marantz will cover the cost of repair. The reason that I purchased such an expensive tuner/CD player in the first place was that I trust Marantz to stand by their products . The cost of repair appears to be about 50% of the cost of the unit!
bluefish.VB
New Member
Hi can you tell me where you got service revision from. I cant find it. Just a bit nervous about the added resistor. It's a repair for a friend and don't want to damage the power suppy.
Thankyou vincent
Durchblicker
New Member
THX for providing this repair guide! I fixed one unit with version 1 and now I want to repair a second one by using this update. Could yo help me to buy the right components: Regarding BC337 45v 0,8A, there are three variants available: BC337-16, BC337-25 and BC337-40, all of them are 45V 0,8A. Which one should I choose?
Again, THX a lot for your support!
Noimpedence
New Member
I bought a replacement- not a Marantz before finding this helpful info. There are 4 PCBs in this unit. Which PCB has the defective components? I ask as I am an amateur and take the view that I have nothing to lose now attempting a repair on my pwn.