Marantz SR7010 - Protection mode , blew transistors twice!

[AVUser001]

Hello Folks

Hope you can help me out on this one,as well..my HT AVR Marantz SR7010, blew transistors twice , went to protectin mode and repaired twice within a month .... driving me crazy!

I did notice there was a similar thread posted earlier Denon 3300 protection mode , but given the circumstances , starting a new thread.

Home Theater setup:

• Marantz SR7010
• 7.1.4
• Front L & R = Focal Chorus 826v Towers , Center = Focal Chorus CC800v , Side Surrounds = Focal Chorus 806v , Surrond Back=Focal Chorus 706
• Heights( Front & Rear) = Bowers & Wilkins CCM683
• Subwoofer: SVS PC13 Ultra
• Power Amp = Emotiva XPA5 Gen2
• Power conditioner= Panamax MR4000

Sequence of events:

1. All was working fine, until one day switching on the system, resulted in a loud pop on my Rear Left Height speaker (BW in-ceiling speaker)
2. Marantz went to protection mode and wont come out through any documented means
3. Engaged Denon out-of-warranty repair. Diagnosis came back with two blown transistors.
4. Dealer replaced transistors, supposedly checked everything fine , post repair and returned back.
5. Meanwhile , without plugging any of the speakers , I tried to do some diagnostics on the speaker/wiring
   1. Checked speaker wiring for short, loose strands , Polarity . No issues found.
   2. Passed a small voltage(9v) to each of the speakers momentarily. Passed
   3. checked the impedence of all the speakers. Remember all measured in the range of ~4-8 ohms.
6. Plugged in an alternate AVR ( Denon AVRS950H) in a 5.1.2 config , in place of the SR7010, but without the Emotiva Amp. - same set of speakers/wiring/power supply , except for the Surround back.
7. Ran through Audyssey calibration, all configured OK. Watched bunch of movies including Atmos , All OK.
8. Plugged the Marantz back into the power , without any of speakers . Came up fine and stayed ON. No issues so far.
9. Connected the PowerAmp & Speakers & Powered on Marantz . Comes up and within few seconds, goes into protection mode, AGAIN! . I felt, it stayed on, until the 12v DC trigger to power amp kicked in..not sure if its coincidence or not.
10. Disconnected everything and tried all documented means to reset etc..Stayed in protection mode.
11. Sent back the unit to D&M Repair. Diagnosis again comes back with two blown transistors. Supposedly its the same FRONT LEFT Channel.
12. Replaced the two transistors and another part(KTC3206-Y-A/P). Unit back in hand.
13. Powered up Marantz by itself , comes up fine and stays ON.

This is where I'm lost on the next steps... There's a good chance it might blow the transistors again, going by history...,while my alternate AVR(Denon) in 5.1.2 continues to entertain me with no issues ..
I do want to return my HT back into 7.1.4 config, with the 7010 ..but also ensure it doesnt kill any of my speakers...this thing has been working fine for few years now.

In both the cases , it was the unit powering up , with no active load.... Not sure whats going on!

HELP !!
Thanks much

 

[lovinthehd]

Can't use the Denon with the external amp I think with that model? Wonder if the pre-amp section is driving it into protection (HDAM run amok?)....what level do you have L/R trim set to? How is the 7010 without external amp over an extended period?

 

[AVUser001]

Can't use the Denon with the external amp I think with that model? Wonder if the pre-amp section is driving it into protection (HDAM run amok?)....what level do you have L/R trim set to? How is the 7010 without external amp over an extended period?

Correct, this Denon has only Sub pre-outs , no channel pre-outs to power amp, like in higher models. I was thinking I might need to get a loaner to simulate my previous config (ie go through emotiva).

On the trim levels, I was pretty sure , it was at 0 for the L/R.., I may have boosted center by a couple of dBs for dialogue , but thats about it , as we sit fairly close and listen at -20 to -25 db usually.

I havent yet tried the 7010 directly with the speakers, after it came back from the repair. A bit reluctant -

Strange thing D&M repair technician reported issue with FRONT LEFT channel , both the times..,no mention of pre-amp... Also , when it went to protection mode the first time, it was my REAR LEFT HEIGHT speaker that had the loud pop , not front left!

I just ran through another 5.1.2 Dolby Atmos demo & test, stressing each of the speakers, including all the 4 height channels taking turns , as the Denon AVRS950H is a 7.2 channel amp only. All seem fine.
Impedences of the L&R measure at about 5 ohms at the AVR end.

 

[PENG]

Hello Folks

Hope you can help me out on this one,as well..my HT AVR Marantz SR7010, blew transistors twice , went to protectin mode and repaired twice within a month .... driving me crazy!

I did notice there was a similar thread posted earlier Denon 3300 protection mode , but given the circumstances , starting a new thread.

Home Theater setup:

• Marantz SR7010
• 7.1.4
• Front L & R = Focal Chorus 826v Towers , Center = Focal Chorus CC800v , Side Surrounds = Focal Chorus 806v , Surrond Back=Focal Chorus 706
• Heights( Front & Rear) = Bowers & Wilkins CCM683
• Subwoofer: SVS PC13 Ultra
• Power Amp = Emotiva XPA5 Gen2
• Power conditioner= Panamax MR4000

Sequence of events:

1. All was working fine, until one day switching on the system, resulted in a loud pop on my Rear Left Height speaker (BW in-ceiling speaker)
2. Marantz went to protection mode and wont come out through any documented means
3. Engaged Denon out-of-warranty repair. Diagnosis came back with two blown transistors.
4. Dealer replaced transistors, supposedly checked everything fine , post repair and returned back.
5. Meanwhile , without plugging any of the speakers , I tried to do some diagnostics on the speaker/wiring
   1. Checked speaker wiring for short, loose strands , Polarity . No issues found.
   2. Passed a small voltage(9v) to each of the speakers momentarily. Passed
   3. checked the impedence of all the speakers. Remember all measured in the range of ~4-8 ohms.
6. Plugged in an alternate AVR ( Denon AVRS950H) in a 5.1.2 config , in place of the SR7010, but without the Emotiva Amp. - same set of speakers/wiring/power supply , except for the Surround back.
7. Ran through Audyssey calibration, all configured OK. Watched bunch of movies including Atmos , All OK.
8. Plugged the Marantz back into the power , without any of speakers . Came up fine and stayed ON. No issues so far.
9. Connected the PowerAmp & Speakers & Powered on Marantz . Comes up and within few seconds, goes into protection mode, AGAIN! . I felt, it stayed on, until the 12v DC trigger to power amp kicked in..not sure if its coincidence or not.
10. Disconnected everything and tried all documented means to reset etc..Stayed in protection mode.
11. Sent back the unit to D&M Repair. Diagnosis again comes back with two blown transistors. Supposedly its the same FRONT LEFT Channel.
12. Replaced the two transistors and another part(KTC3206-Y-A/P). Unit back in hand.
13. Powered up Marantz by itself , comes up fine and stays ON.

This is where I'm lost on the next steps... There's a good chance it might blow the transistors again, going by history...,while my alternate AVR(Denon) in 5.1.2 continues to entertain me with no issues ..
I do want to return my HT back into 7.1.4 config, with the 7010 ..but also ensure it doesnt kill any of my speakers...this thing has been working fine for few years now.

In both the cases , it was the unit powering up , with no active load.... Not sure whats going on!

HELP !!
Thanks much

If you were running 7.1.4, you should set the FL and FR to pre-outs, did you do that?

To help identify the root causes, you should ask for a report of the repair and it should tell you exactly which two transistors were blown, that is, their part numbers and where they were used.

 

[AVUser001]

If you were running 7.1.4, you should set the FL and FR to pre-outs, did you do that?

To help identify the root causes, you should ask for a report of the repair and it should tell you exactly which two transistors were blown, that is, their part numbers and where they were used.

Correct, thats what the configuration was (with Marantz pre-outs of L/R/C & Side Surrounds going to 5 channel Emotiva Amp)..,while the on-board amp was driving the Rear Surrounds & 4 Height channels.

Yes, I've the report ..,the parts that were replaced are
KTC3206-Y-AT/P, TR AVR4308CI
TRANSISTOR 2SD2560Y AVR2106
TRANSISTOR 2SB1647Y AVR2106

 

[TLS Guy]

The first thing to check is that you have no shorts in the wiring to any speaker. First look at your wiring carefully.

Next it could be you have some impedance loads too low for that receiver. Unfortunately you can not trust a manufacturer to be honest about the impedance of a speaker. All receivers should be stable to four ohms but even less are now than they used to be.

I suspect you measured the DC resistance of the speakers and not the impedance. How did you get your measurements? You can not use a multimeter.

B & W speakers are renowned for being difficult loads. So I find it interesting that it was a B & W speaker that blew out transistors.

I'm pretty certain you have a load your receiver does not like. I don't use receivers by the way and never will.

 

[PENG]

Correct, thats what the configuration was (with Marantz pre-outs of L/R/C & Side Surrounds going to 5 channel Emotiva Amp)..,while the on-board amp was driving the Rear Surrounds & 4 Height channels.

Yes, I've the report ..,the parts that were replaced are
KTC3206-Y-AT/P, TR AVR4308CI
TRANSISTOR 2SD2560Y AVR2106
TRANSISTOR 2SB1647Y AVR2106

That helps!
The KTC3206Y is a small transistor, apparently used in the bias circuit.
The 2SD2560Y and 2SB1647Y are the Darlington (pairs) transistors, one is the NPN, the other PNP. They are the output devices, so you blew the output devices!!

By the way, ignore the numbers AVR2106 and AVR4308CI, those are Denon AVR models, I happened to own the AVR4308CI lol.. I think their computer spilled that out just to indicate that the same output devices were used in the AVR2106 and the little one was used also in the AVR4308CI, that's all.

Note: I always suspect that's (standardization) one reason why even the lower mid range AV receivers such as D&M's often measured as good or better (in two channel driven) than some low to mid end integrated amps rated below 100 WPC. It the power of "economy of scale" that allowed them to the same output devices in their lower end products.

Now, if you are using the Emotiva amp to drive the L/R/C/SL/SR channels then the two output transistor pairs blew would likely be caused by a short in one of your height/Atmos speakers. You should double check the wires and the connectors, if you are sure all of the speakers are not to blame.

I hope not, but if it tripped on "protection mode" again, please carefully observe or even record the LED flashing sequence because they should at least tell you if the protection mode was triggered by either of the following:

a) Short circuit, or high DC output
b) Thermal (that's unlikely in your case)
c) Current protection (quite possible in your case).

Or you can press the right combinations of buttons to see the history. The service tech likely have already clear the history log but you can still try in case he hasn't done so.

 

[AVUser001]

The first thing to check is that you have no shorts in the wiring to any speaker. First look at your wiring carefully.

Next it could be you have some impedance loads too low for that receiver. Unfortunately you can not trust a manufacturer to be honest about the impedance of a speaker. All receivers should be stable to four ohms but even less are now than they used to be.

I suspect you measured the DC resistance of the speakers and not the impedance. How did you get your measurements? You can not use a multimeter.

B & W speakers are renowned for being difficult loads. So I find it interesting that it was a B & W speaker that blew out transistors.

I'm pretty certain you have a load your receiver does not like. I don't use receivers by the way and never will.

Thanks @TLS Guy .

I did check all the speaker wiring for shorts. Like I mentioned in the post, I've infact plugged in an alternate receiver into the same spot and have been watching movies fine (including Atmos w/4 Height channels (B&W)). I had also measured the resistance of the speakers from the AVR end , via the wiring..,as well the 9v test , all at the AVR end of wiring. It'd become visible, with these tests, if there were a short?

You're right, I just measured the resistance using multimeter, not the impedence w/AC.

Both the times the AVR went to protection mode, when powering up, with no "active" load from speakers.

This is an existing setup I've been running for few years now ..,with the AVR pre-outs to the PowerAmp for 5 channels(FR,FL,Center, Side Surrounds), leaving the AVR to handle the Surround back & 4 Height channels.

The D&M repair guy says FRONT LEFT , which actually goes through Emotiva Amp..while the loud pop I heard from REAR LEFT HEIGHT. Confusing diagnostics.

Do you recommend any alternate meter/mechanism to test ?

 

[PENG]

You're right, I just measured the resistance using multimeter, not the impedence w/AC.

You mentioned 9 V, so if it is a multi-meter it would be 9 VDC. That's generally not a good idea. For DC, A lower voltage would be preferred. In your case it would be okay though, as after the fact you now know the dc resistance of the speakers are at least 4 ohms but don't leave the voltage on too long, 1 second should be enough to read it.

 

[PENG]

The D&M repair guy says FRONT LEFT , which actually goes through Emotiva Amp..while the loud pop I heard from REAR LEFT HEIGHT. Confusing diagnostics.

Wow, why piece meal info, is this a test/tease exercise lol?? Good thing so far I think I pass the test.

Remember I asked you right off the bet if you select FL/FR to Pre-outs and your response was affirmative?
I also told you in my post#7 that "would likely be caused by a short in one of your height/Atmos speakers"

So that's why it blew the FL transistor because that channel would have been re-assigned to drive your rear left height.

You really need to double check the connectors, wires and the speaker, or it will happen again!!

 

[AVUser001]

The KTC3206Y is a small transistor, apparently used in the bias circuit.
The 2SD2560Y and 2SB1647Y are the Darlington (pairs) transistors, one is the NPN, the other PNP. They are the output devices, so you blew the output devices!!

Ok Thanks, double checked..,they're exactly the same transistors replaced in both the service calls, within the month.

Now, if you are using the Emotiva amp to drive the L/R/C/SL/SR channels then the two output transistor pairs blew would likely be caused by a short in one of your height/Atmos speakers. You should double check the wires and the connectors, if you are sure all of the speakers are not to blame.

If there's a short in the height channels, will it still pass the 9v test, resistance measurements, Audyssey test tones and a 5.1.4 Atmos demo test? ..could very distinctively hear rain falling from the sky! ..Maybe I'm missing something., maybe I'll now reconfigure those Heights as Mains and test again with louder music.

I hope not, but if it tripped on "protection mode" again, please carefully observe or even record the LED flashing sequence because they should at least tell you if the protection mode was triggered by either of the following:

a) Short circuit, or high DC output
b) Thermal (that's unlikely in your case)
c) Current protection (quite possible in your case).

Or you can press the right combinations of buttons to see the history. The service tech likely have already clear the history log but you can still try in case he hasn't done so.

It was very clearly the dreaded power indicator flashing red every 0.5 seconds , as in

Thanks again

 

[highfigh]

Thanks @TLS Guy .

I did check all the speaker wiring for shorts. Like I mentioned in the post, I've infact plugged in an alternate receiver into the same spot and have been watching movies fine (including Atmos w/4 Height channels (B&W)). I had also measured the resistance of the speakers from the AVR end , via the wiring..,as well the 9v test , all at the AVR end of wiring. It'd become visible, with these tests, if there were a short?

You're right, I just measured the resistance using multimeter, not the impedence w/AC.

Both the times the AVR went to protection mode, when powering up, with no "active" load from speakers.

This is an existing setup I've been running for few years now ..,with the AVR pre-outs to the PowerAmp for 5 channels(FR,FL,Center, Side Surrounds), leaving the AVR to handle the Surround back & 4 Height channels.

The D&M repair guy says FRONT LEFT , which actually goes through Emotiva Amp..while the loud pop I heard from REAR LEFT HEIGHT. Confusing diagnostics.

Do you recommend any alternate meter/mechanism to test ?

Did you test only on the wire pair that go to each speaker, or did you test from each wire to all of the others, as well as referencing the speaker wires to the house's electrical ground and neutral? You need to reference each wire to all others in order to find these problems. If a speaker cable is pinched, it can kill an amplifier- you may not see a short from the red to the black, but it may be shorted to the white or green (or between other wires).A cable that's pinched between something and a conduit can cause this if the insulation has been breached.

You didn't connect the AVR and the Emotiva to the same speaker wires, did you? You can't do that.

 

[Pogre]

Everything seems to be pointing toward a connection issue.

 

[AVUser001]

You mentioned 9 V, so if it is a multi-meter it would be 9 VDC. That's generally not a good idea. For DC, A lower voltage would be preferred. In your case it would be okay though, as after the fact you now know the dc resistance of the speakers are at least 4 ohms but don't leave the voltage on too long, 1 second should be enough to read it.

Those are two different tests, I did.
1) Passed a short 9v DC ( ~1-2 seconds) to each of the speakers using a 9v battery and observed audio.
2) Measured the resistance on each of the speaker connectors(bannana plugs) with multimeter.

 

[AVUser001]

Wow, why piece meal info, is this a test/tease exercise lol?? Good thing so far I think I pass the test.

Oh not at all. Thought I had mentioned that in my first post as in
"Sent back the unit to D&M Repair. Diagnosis again comes back with two blown transistors. Supposedly its the same FRONT LEFT Channel."

Remember I asked you right off the bet if you select FL/FR to Pre-outs and your response was affirmative?
I also told you in my post#7 that "would likely be caused by a short in one of your height/Atmos speakers"

So that's why it blew the FL transistor because that channel would have been re-assigned to drive your rear left height.

Correct, FL/FR pre-outs to PowerAmp.

Oh Ok , Now I get the picture..,the FL in AVR got re-assigned to drive the REAR LEFT HEIGHT ...which is where I heard the loud pop in the first place, when it went into protection. Makes sense now..

Aligns with @TLS Guy 's comment about the B&W speakers...

But again, if there was a short or connection issue, will it still pass all the resistance, 9v & Atmos tests on the Height channels..?

I'll redo those tests now again, focussing on the REAR LEFT HEIGHT..

Thanks much @PENG & @TLS Guy ..we've narrowed it down, I think.

 

[PENG]

Oh not at all. Thought I had mentioned that in my first post as in
"Sent back the unit to D&M Repair. Diagnosis again comes back with two blown transistors. Supposedly its the same FRONT LEFT Channel."

Sorry I did mess that then..

But again, if there was a short or connection issue, will it still pass all the resistance, 9v & Atmos tests on the Height channels..?

No it wouldn't, but it may pass a multi-meter resistance test if it was an intermittent fault that could be a pinched wire somewhere (as highfigh mentioned), or more likely one in the connector. What kind of connector do you use, or were they just hard wired to the speaker and amp terminals?

I'll redo those tests now again, focussing on the REAR LEFT HEIGHT..

You said you tried another 7 channel avr, did you have the rear height connected to that other AVR?

we've narrowed it down, I think.

Agreed, but be very careful, you don't want to have to send it out the 3rd time. If you cannot find the root cause, you may want to have the rear height speakers physically disconnected from the 7010's binding posts and use it for a week or so before trying something else.

 

[AVUser001]

Oh Ok , Now I get the picture..,the FL in AVR got re-assigned to drive the REAR LEFT HEIGHT ...which is where I heard the loud pop in the first place, when it went into protection. Makes sense now..

Aligns with @TLS Guy 's comment about the B&W speakers...

But again, if there was a short or connection issue, will it still pass all the resistance, 9v & Atmos tests on the Height channels..?

I'll redo those tests now again, focussing on the REAR LEFT HEIGHT..

Actually I need some clarification here.., I had made a note of the speaker connections before sending the AVR for repair.
The REAR LEFT HEIGHT was actually connected to the HEIGHT 2 LEFT on the AVR.

If thats the case, will it still Reassign the FRONT LEFT to drive the Rear Left Height ? Arent those separate dedicated channels or they sharing the same o/p circuit(transistors) on the board ?

 

[AVUser001]

What kind of connector do you use, or were they just hard wired to the speaker and amp terminals?

Bannana plugs on the AVR side. On the speaker side, its the spring terminals on the frame, as in

You said you tried another 7 channel avr, did you have the rear height connected to that other AVR?

Yes, I had connected the Denon 7.2 channel amp in a 5.1.2 config.., first with the Front Heights.., then with the Rear Heights. Both worked fine, as mentioned in my earlier post #3 .

"I just ran through another 5.1.2 Dolby Atmos demo & test, stressing each of the speakers, including all the 4 height channels taking turns , as the Denon AVRS950H is a 7.2 channel amp only. All seem fine."

Thats why its baffling.

 

[PENG]

Bannana plugs on the AVR side. On the speaker side, its the spring terminals on the frame, as in
View attachment 32937



Yes, I had connected the Denon 7.2 channel amp in a 5.1.2 config.., first with the Front Heights.., then with the Rear Heights. Both worked fine, as mentioned in my earlier post #3 .

"I just ran through another 5.1.2 Dolby Atmos demo & test, stressing each of the speakers, including all the 4 height channels taking turns , as the Denon AVRS950H is a 7.2 channel amp only. All seem fine."

Thats why its baffling.

Assuming you are using the same wires for connection to the Denon, then you may want to open up the banana plug to see if the the two leads are properly separated with no chance of touching when wiggled.

 

[AVUser001]

Assuming you are using the same wires for connection to the Denon, then you may want to open up the banana plug to see if the the two leads are properly separated with no chance of touching when wiggled.

Yes, exactly the same speakers/cables to Denon in 5.1.2. Checked all the connectors on both sides(AVR,Speakers), all fine. Infact I had opened the banana plugs earlier and ensured all is fine. I was infact hoping I'd find something.

Just came back, after another successful Audyssey test tones to all the speakers , as well additional Atmos test tones. The Rear height speakers reproduce the atmos tracks faithfully, didnt notice any drop in volume or noise.

I'm convinced there's nothing wrong with the speakers or cabling after all these tests with the alternate AVR.