My marantz sr5008 often going into protection mode
- Thread starter sree0320
- Start date
Srinath_seshadri
New Member
This could be a case of the output transistors shorting to the heat sink. I've see and fixed this in Onkyo's from the early 2000's.
They put the transistors on heat sinks without thermal compound or mica. You put mica and thermal paste between the transistor and the heat sink, and it wont short cos mica wont conduct electricity and it will run cooler, cos mica and thermal paste conduct heat.
You can open it, run it, and when it goes into protect, spray compressed air at the transistors. You may locate a single source of the issue ... or may not.
I found problems with a lot of amps that way.
Cool.
Srinath.
They put the transistors on heat sinks without thermal compound or mica. You put mica and thermal paste between the transistor and the heat sink, and it wont short cos mica wont conduct electricity and it will run cooler, cos mica and thermal paste conduct heat.
You can open it, run it, and when it goes into protect, spray compressed air at the transistors. You may locate a single source of the issue ... or may not.
I found problems with a lot of amps that way.
Cool.
Srinath.
rayvonnee
Active Member
I recommend going to a nearby service center. My uncle faced such issue with a brand new marantz nr1504. It would go into protect mode. Avr was in warranty and so got it repaired free. I was told only some parts inside were loose due to which the avr was going into protect mode. He just raised the avr from one side and dropped it slowly on the table and the avr began working. Hee then took 30mins to open it up and tighten up some loose components and the avr started no issues till now. So if avr is in warranty do not attempt any repair yourself except for resetting the avr.
vinothkumar
Well-Known Member
+1 for rayvonnee's comment.
Dont mind whether you have warranty or not, take it to a service center and get it repaired. Get some advises from the service guys regarding usage at heavy volume.
If you really know how to repair as Srinath said or if you already have attempted repairing by yourself then go ahead. But this will be at your own risk.
Best approach is to go to service center.
Dont mind whether you have warranty or not, take it to a service center and get it repaired. Get some advises from the service guys regarding usage at heavy volume.
If you really know how to repair as Srinath said or if you already have attempted repairing by yourself then go ahead. But this will be at your own risk.
Best approach is to go to service center.
Amitkg
Active Member
@sree0320
Is there any low voltage / low frequency problem in your area recently? If yes, get a good voltage stabilizer and see whether issue persists or not. In my case, it happened with the advent of summer. During summer, voltage/frequency drop is very common across India; sudden dip in voltage/frequency sends A/V equipments into protection mode.
Is there any low voltage / low frequency problem in your area recently? If yes, get a good voltage stabilizer and see whether issue persists or not. In my case, it happened with the advent of summer. During summer, voltage/frequency drop is very common across India; sudden dip in voltage/frequency sends A/V equipments into protection mode.
Thanks for the quick reply. But already I have sent it to marantz distributor Mz audio.
Few weeks back it came from service as the same situation was there. It was working fine for almost a fortnight there at service centre. So I don't have any option but taking it back. After two days of playing it again it went to protection mode. Then I thought my house wiring may have problem and changed it. Again I have had the same problem that's why I sent it back. Let me see what he will do
Few weeks back it came from service as the same situation was there. It was working fine for almost a fortnight there at service centre. So I don't have any option but taking it back. After two days of playing it again it went to protection mode. Then I thought my house wiring may have problem and changed it. Again I have had the same problem that's why I sent it back. Let me see what he will do
As srinath said heat might be the problem cause I can almost boil an egg on the top cover. The same thing I told to service centre people but they said that it is quite common on new D&M avr as they implented new transformer technology ( iam knoob at this)
From my research I found that it is working fine till 60% volume even with long runs but there after it is frying.
Yes I have denon 1610 with same wharfedale 9.5 floor stands which is running quite comfortable even at higher volume without heating much.
I heard marantz receiver with wharfedales at my friends place and fell in love with them that's why I purchased this. Now it is troubling me.
From my research I found that it is working fine till 60% volume even with long runs but there after it is frying.
Yes I have denon 1610 with same wharfedale 9.5 floor stands which is running quite comfortable even at higher volume without heating much.
I heard marantz receiver with wharfedales at my friends place and fell in love with them that's why I purchased this. Now it is troubling me.
Srinath_seshadri
New Member
OK you have it overheating @ 60% volume, but at the svc center it is not ???
You may have bad voltage at your house/step down transformer. The lower the voltage, the higher current it will draw ... but you also will be running a higher volume for the same spl on the same speakers.
There is these 2 things that could be at play -
1. For example - You have 100 db at 65% volume, but you are only supplying it 100v @ your house.
At the service center it will make 100 db @ 50% volume if they supply it 117v.
But if they also set it to 65% volume, due the the higher voltage, it will be sending more output - maybe 105 db, and it will make less heat cos its sending it out as power.
2. You need to run it at its best voltage range, its better for it. Say the transistors are good between 60 and 80 v, they may work most efficiently at ~72v, so they may have built it to get 72v and regulated it @ 72. By feeding it less than 72, you have rendered the 72v regulators redundant (they will cut it down, they cant step it up) and you're sending it say 65v. It will work, but its making more heat, and you run it @ higher volume and it sends more as heat and so on ...
Cool.
Srinath.
You may have bad voltage at your house/step down transformer. The lower the voltage, the higher current it will draw ... but you also will be running a higher volume for the same spl on the same speakers.
There is these 2 things that could be at play -
1. For example - You have 100 db at 65% volume, but you are only supplying it 100v @ your house.
At the service center it will make 100 db @ 50% volume if they supply it 117v.
But if they also set it to 65% volume, due the the higher voltage, it will be sending more output - maybe 105 db, and it will make less heat cos its sending it out as power.
2. You need to run it at its best voltage range, its better for it. Say the transistors are good between 60 and 80 v, they may work most efficiently at ~72v, so they may have built it to get 72v and regulated it @ 72. By feeding it less than 72, you have rendered the 72v regulators redundant (they will cut it down, they cant step it up) and you're sending it say 65v. It will work, but its making more heat, and you run it @ higher volume and it sends more as heat and so on ...
Cool.
Srinath.
elan13
Member
^ Srinath it was exactly the problem with my AVR. Voltage was the culprit.
Will inclusion of voltage stabilizer help in OP case?
Will inclusion of voltage stabilizer help in OP case?
Yes, I too had the same thought.
But why I am so reluctant is denon 1610 which Is inferior in specs working well with out much heat for the same SPL I listen to, with same speakers for the past 5 years in the same house.
Infact I am cranking up more vol on denon but it is safe.
If voltage drop was the issue then denon is working fine. This I couldn't understand.
But why I am so reluctant is denon 1610 which Is inferior in specs working well with out much heat for the same SPL I listen to, with same speakers for the past 5 years in the same house.
Infact I am cranking up more vol on denon but it is safe.
If voltage drop was the issue then denon is working fine. This I couldn't understand.
I was using denon1610 which is inferior in specs working fine at the same SPL for the past 4 years at the same location. This is why I I am thinking that marantz may be defective.
Small, 80hz cross over and LFE+MAIN
Srinath_seshadri
New Member
I've never used a step down or a stabilizer really. However what you have in your favor is that 220 drops to 200, or 180 ... never down to 120 ... so you have a inherent safety built in. So what you need is a auto adjusting variac.
No clue if something like that exists ... I can see how to build it, but a 1000+ watt variac with the controllers etc etc will not be cheap if you built it.
So check specs on the stabilizer ... you need to get clean AC out of it, and what its range of boost/buck is.
BTW in the US we almost have the reverse problem. 110v was the old spec, and a lot of equipment was rated for 110. LOL, what a joke. They speced it to 117 a few years ago, and ... get this, as I type, my monster HT5000 is showing 123.1. Yea, we're running 10+% higher. Seems to be working fine though. If I recall, I've seen as high as 126+ on it. 15% more ???
Cool.
Srinath.
Next time try only LFE. When you are outputting LFE+Main all the very low frequencies are going into your front speakers. Nowadays AVR specs are given at 1 or 2 channel driven. Practically you get half what is rated with all 5 channels driven. Wharfedales are rates at 6 ohms but when playing the impedance drops to 4 ohms or so.
AVRs also go into protection mode when the loudspeaker impedance falls at some particular frequency to a very low level. One of my friends AVR output transistor got completely burned due to this issue. Even after replacing the output transistors the AVR could not be turned to higher volume. Only after he replaced the Jamo speakers this problem got solved. My advise do not suspect only the voltages, as sometime the culprit could be the speakers too. If the speakers are the culprit then the AVR will defnitely go to protection mode when the volume is jacked up. Period. Infact this is an indication of a well designed AVR.
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