Strange Problem Marantz PM5005

Btw, the power cord of the amp is 2-pin, no point for the ground.

How about the power socket of the amp? Is it two-pin type, or 3-pin type?

If 2-pin type socket, then you're using correct power cord. It means your device is double insulated type meant to work with floating ground. I remember the Marantz CD6003 had a power socket which was physically similar to IEC 3-pin male socket but ground pin was missing. But this quite normal - just check any DVD or Blu-ray player... They're all powered by 2-pin power cords.

If 3-pin type socket, then you're using wrong power cord. AFAIK, a 40-50W amplifier must be run with three lead supply, so my guess is you're using the wrong power cord and operating your amp with floating ground. It's a serious safety hazard, BTW.

On a related note, I see people randomly use European/Schuko power cords to power devices at home, just because Schuko male connector plugs into Indian wall sockets. European power cords must be used only with matching wall socket which provides ground contact. Otherwise it is a big safety hazard.
 
It's 2-pin type socket and the power cord is also 2-pin.


This is what's happening now : All cords in, keeping the amp plugged on for a while, turning on the amp, input light and speaker light lit, I press the source direct and loudness buttons, the amps stays on and it's still staying on and probably will stay now.
 
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Now, it's playing fine. So this is what I understood.

Keeping the amp with the power on for a while (30-40 mins), then turning on the amp, everything is steady and when the amp is heated up, you can turn it off / on and it will stay on. Once the amp is cooled down, same thing will happen for sure.
 
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Another person told me that it could be a case of dry soldering or IC overheating. No clue.

With your amp & the power cord being the constant, something is missing in your place when compared with your friends's & dealer's place.
 
It doesn't matter if I connect the speakers or not, I'm just connecting the power cord and the amp will go to protection mode. At the dealer, the amp doesn't go to protection mode. If I keep the amp turning on the power switch for 30-40 mins, the amp run smoothly. And as long as the amp is running and staying warm / hot, it won't turn off or the problem will show up even if you turn the amp off for a while.
 
It seems to be a strange problem.
Try this, disconnect all appliances i.e TV, fridge, etc from the electrical sockets and see if only the amp connected stays on. There might be (a possibility) that some other equipment is giving problems i.e grounding and causing this to happen. I suspect it might be the fridge as it keeps switching on & off on intervals. Now this might be the case that when the fridge is in off position your amp must be working & otherwise it starts giving problem.

This is just a stupid guess, no harm in trying.
 
It could be. Just now, I turned the fan high and the amp showed mute and turned off. Also, I saw the speaker wires with some strands torn and touching the outer cover of
the banana plugs, could that be some problem ?
 
How about the power socket of the amp? Is it two-pin type, or 3-pin type?

If 2-pin type socket, then you're using correct power cord. It means your device is double insulated type meant to work with floating ground. I remember the Marantz CD6003 had a power socket which was physically similar to IEC 3-pin male socket but ground pin was missing. But this quite normal - just check any DVD or Blu-ray player... They're all powered by 2-pin power cords.

I have a Marantz PM5004 which has two pin type socket and power cord. However i am getting mild shock when i touch the amplifier. The tester also glows when i touch the amplifier body. Considering the amplifier is 2 pin type, is there any way to add grounding?

My schitt modi DAC also uses two pin power cord (but it has 3 pin socket input. It also has similar issue. But when i use my Desktop power cord which has a pin, it is fine. I am planning to buy a 3 pin power cord and replace.

What can be done for my Marnantz amp which doesn't have 3 pin socket?
 
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Had the same problem @anubisX ..managed to solve it after a lot of bother. My Marantz-pm5005 ampli went into standby mode after a few hours of use and stayed there. Went back to to the dealer (Cobra, Paris) he pugged it in worked fine ! Came home plugged it in went straight into standby flashing away. I'd tried everything different cables, one speaker cable et a time etc etc etc. So its seems the ample stays in standby safety mode and stays there until it receives a voltage it likes ! (stay with me).. I took it in the bathroom which uses different circuit from lounge and bedrooms. Plugged it in, the amp went off stand by mode and worked perfectly. The took it back into the room I use it in plugged it in worked fine until I used the 'Recorder-1 and Recorder-2' IN sockets on the back of the amp which sent it straight back into standby mode ! I then had to plug in the bathroom again to get it out of standby mode. Now I've been using the CD, Tuner, Phono and Network entrees only. It works perfectly. So for me it is and issue with the Recorder-1 and Recorder-2 in line.. don't use them. Sorry for the long winded explanation.
 
Had the same problem @anubisX ..managed to solve it after a lot of bother. My Marantz-pm5005 ampli went into standby mode after a few hours of use and stayed there. Went back to to the dealer (Cobra, Paris) he pugged it in worked fine ! Came home plugged it in went straight into standby flashing away. I'd tried everything different cables, one speaker cable et a time etc etc etc. So its seems the ample stays in standby safety mode and stays there until it receives a voltage it likes ! (stay with me).. I took it in the bathroom which uses different circuit from lounge and bedrooms. Plugged it in, the amp went off stand by mode and worked perfectly. The took it back into the room I use it in plugged it in worked fine until I used the 'Recorder-1 and Recorder-2' IN sockets on the back of the amp which sent it straight back into standby mode ! I then had to plug in the bathroom again to get it out of standby mode. Now I've been using the CD, Tuner, Phono and Network entrees only. It works perfectly. So for me it is and issue with the Recorder-1 and Recorder-2 in line.. don't use them. Sorry for the long winded explanation.
Can you please check if the Phase & Neutral are reverse at the plug in your listening room ?

Did this problem happen even with Nothing connected to the Recorder Inputs ?
 
I have fiddled around with many amps with protection issues and in one weird case the owner even though that failing electronic equipment at his home was due to some Vaastu misses during construction.

Protection mode is due to external and internal issues - believe me, it has nothing to do with 15 amp wiring, will not go away if you use a stabilizer and will not be resolved if you say your prayers :) And yes, the funny thing about protection issues, they always seem to disappear at the dealer's place or at the service center, they also tend to disappear momentarily when the amp is back from repairs, only to reappear again if the root cause is not identified and rectified.

Ensure you have a good and clean power supply source (for example my listening room and bench for repairs are powered by dedicated cabling from the main CB box), ensure that your speakers have the right impedance-range ratings and speaker cabling is compliant. Ensure that the amp has proper ventilation especially if it is played at high levels. Also avoid using multiple socket adaptors (used to connect multiple devices to a single plug point), use a good quality powerstrip instead. Never connect the amplifier to a stabilizer or UPS, never....These are the external factors.

There are some basic factors that need to be checked and mitigated. This post will throw some light on this situation.
 
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