Great video. I had a Rotel rx-1052 that had a weak, fuzzy left channel. The technician quickly found a shorted resister, but because it's a Rotel he checked for voltage leaks caused by that glue. He found a constant 5 volts on the right output channel. After cleaning all the glue from the components, the 5 volt leak to output was gone. He said the glue Rotel used to secure heavier components to be soldered was an insulator when it was applied, but after years of exposure to heat it gradually becomes carbonized and therefore conducts...causing all kinds of problems. The constant 5 volts to the right speaker would have, over time, ruined the voice coil. I hope Rotel figured out that issue!
It’s not a Rotel issue. It’s an industry wide problem. I was STUNNED to find out that some companies are STILL using the same glue. That’s when I realized it was a feature, not a fault. It’s the most blatant form of planned obsolescence I’ve ever seen. I opened up a Definitive Technology BP9060 plate amplifier to find the damn thing slathered in the same yellow epoxy stuff. The BP9060 is not vintage gear. It was released just a couple years ago. Def Tech has a horrific track record when it comes to amplifier reliability, and that is definitely one reason why. They don’t just use a dab here or there, they slap it all over the board, all over items that heat up, all over conductors, all over everything. I sincerely don’t understand how there hasn’t been several dozen class action lawsuits about this exact practice of setting a time bomb in every amp they build, that causes them to kick the bucket, blowing up usually a year or two out of warranty. Some manufacturers have definitely figured this out and moved away from it, unfortunately others have not.
I should also say, I believe they intentionally build the amps with flawed , undersized capacitors that they know will eventually fail, rendering the amp useless. Then they get sent in to def tech to be replaced for $300 while they go head and fix the caps they know are 90% likely to be the problem. That’s how all thr 7000 series amps are built. It’s a design flaw intended to blow up the amps out of warranty, but they get plenty that blow under warranty still too. I don’t know how one would go about proving it, but this kind of crap needs to be rooted out. Cheers.
Love your work. I wish you had a chance to listen to the 1080's big brother, a Rotel RB-1090 on great speakers. I've got 2 of them. The bass is a joy to hear/feel.
What timing, working on my Rotel RB-981amp, replacing the 4 large leaky capacitors on my 20 year old unit. Had to clean up a lot of glue on the board too !
Hello I am enjoying your content , I have just recently purchased a Rotel RB1080 and a Rotel Controler Amp RC1070 , both seem to be working fine I paid $1800 for the two units my question is , is this a fare price and what receiver do you recommend I use
To me it would not make sense that the open diode caused the power transistor to short out as the bias current would drop low to almost nothing. But if the same diode shorted out to begin with the bias voltage would be wrong and the output transistors could get stressed because of inbalances idle current. Nice video by the way.
Thank you for this video, i have same amp and have that specific problem. It has been on repair for that problem twice. And it is not still fixed. Good to know what to check.
Really great video. I have a Rotel RB 1070, I haven’t opened it up yet, but do you happen to know if They’ve got fairly similar guts? No worries if you don’t know. My left channel is out, I’ll get around to it shortly. What I was really hoping to figure out is what you usually use to remove that god damn glue in a relatively easy way? The brown, super degraded glue isn’t an issue, that’s easy enough. But I am constantly running into amps that are just COVERED in it. They might as well have just straight dipped the entire board in it. Do you know any solvents that will eat through it without destroying the board or any components? Or any product that will at least soften it up to make it manageable. I have to catch myself and stop my ocd from taking over because if not I’ll realize I just spent 2.5 hours picking a 3” X 3” section of glue and barely making A dent in it. You either use metal tools and risk damaging the board and components in case you slip, or you use plastic and make it 10x more difficult. Any help would be sincerely appreciated. Thanks !!
Freeze spray can help sometimes. Makes the softer stuff more brittle and bigger chunks come off when you pick at it. If it's not on components, traces or jumpers you can just let it be. It doesn't migrate anywhere.
I have just bought a Peavey CS1000 rack mount power amp... When you plug it in and flick the switch on, the rear panel glass fuse instantly blows. But looking inside the amp, there is a power board with 2 glass fuses, those arent blown.. It just blows the main rear panel glass fuse.. Ive inspected the board, with my limited knowledge, and found no other obvious faults.. But removed and tested the output T0-3 transistors, and found 4 to be faulted to ground... Could this be what is causing the main rear panel fuse to blow constantly?!? I just thought its strange, that the internal power board fuses are still perfectly fine, when it rectifies AC to DC etc... But it blows the mains AC rear panel fuse... Im really hoping its just the transistors at fault, im new to repairing electronics, and this is my first project. I really dont want my first project to be a failure :(
One of my colleagues gave me a Marantz PM-30 amplifier that does not produce any output whatsoever. He had told me this before giving it to me. I'm a communication electronics technician who normally troubleshoots instrumentation landing systems (localiser, glideslope etc) and this will be my first stint with an integrated amplifier. Wish me luck 😂
I have a 4 channel car amp thats immediately blowing the 2 20amp fuses on the amp as soon as its inserted into the holder on the amp, I have only the power cable and the ground cable connected. The remote wire, rc cables and speaker wires are all disconnected. Without even turning the amp on its blowing the fuses... please assist
wow i wish i had that kind of knowledge :-) do you know where to find a scemetic of a BLADELIUS MK 2 ? it went in protection mode several times and then also blew a fuse. :-/
If you want to criticize someone on the internet using lots of exclamation points as if you’re yelling at them, you should learn English and you should use correct punctuation and grammar!!!!!!!!!!!!!
you should tell us why this transistor is get short , not just open the box and search for short , reason for short that is question , if you want teach out electronic !!
If you want to criticize someone on the internet using lots of exclamation points as if you’re yelling at them, you should learn English and you should use correct punctuation and grammar!!!!!!!!!!!!!
Not always possible to locate the cause after the event. However in this case the open diode would have caused the main output transistors to run hard up against the power rail. This would continue until the weakest output transistor failed from excessive heat. Not all transistors come out of the factory identical and it also means the rest probably should be replaced as they also were stressed out with the heat. Note also the TH601 protection thermistor isnt even physicaly connected to the failed transistors heat sink and so was never able to protect the positive bank.
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Great video.
I had a Rotel rx-1052 that had a weak, fuzzy left channel.
The technician quickly found a shorted resister, but because it's a Rotel he checked for voltage leaks caused by that glue.
He found a constant 5 volts on the right output channel.
After cleaning all the glue from the components, the 5 volt leak to output was gone.
He said the glue Rotel used to secure heavier components to be soldered was an insulator when it was applied, but after years of exposure to heat it gradually becomes carbonized and therefore conducts...causing all kinds of problems.
The constant 5 volts to the right speaker would have, over time, ruined the voice coil.
I hope Rotel figured out that issue!
It’s not a Rotel issue. It’s an industry wide problem. I was STUNNED to find out that some companies are STILL using the same glue. That’s when I realized it was a feature, not a fault. It’s the most blatant form of planned obsolescence I’ve ever seen. I opened up a Definitive Technology BP9060 plate amplifier to find the damn thing slathered in the same yellow epoxy stuff. The BP9060 is not vintage gear. It was released just a couple years ago. Def Tech has a horrific track record when it comes to amplifier reliability, and that is definitely one reason why. They don’t just use a dab here or there, they slap it all over the board, all over items that heat up, all over conductors, all over everything. I sincerely don’t understand how there hasn’t been several dozen class action lawsuits about this exact practice of setting a time bomb in every amp they build, that causes them to kick the bucket, blowing up usually a year or two out of warranty. Some manufacturers have definitely figured this out and moved away from it, unfortunately others have not.
I should also say, I believe they intentionally build the amps with flawed , undersized capacitors that they know will eventually fail, rendering the amp useless. Then they get sent in to def tech to be replaced for $300 while they go head and fix the caps they know are 90% likely to be the problem. That’s how all thr 7000 series amps are built. It’s a design flaw intended to blow up the amps out of warranty, but they get plenty that blow under warranty still too. I don’t know how one would go about proving it, but this kind of crap needs to be rooted out. Cheers.
Love your work. I wish you had a chance to listen to the 1080's big brother, a Rotel RB-1090 on great speakers. I've got 2 of them. The bass is a joy to hear/feel.
Love how you troubleshoot the unit... Thanks for the HD content
What timing, working on my Rotel RB-981amp, replacing the 4 large leaky capacitors on my 20 year old unit.
Had to clean up a lot of glue on the board too !
Hello I am enjoying your content , I have just recently purchased a Rotel RB1080 and a Rotel Controler Amp RC1070 , both seem to be working fine I paid $1800 for the two units my question is , is this a fare price and what receiver do you recommend I use
Brilliant vid. About to pick up a RMB 1075 with noisy left channel. This gives me a great head start.
Great video very informative. Which style of electrolytic capacitors are you using? Also what is the thickness of the thermal pads you used.
Radial or snap in?
How much did this repair cost? Nice work by the way!
To me it would not make sense that the open diode caused the power transistor to short out as the bias current would drop low to almost nothing. But if the same diode shorted out to begin with the bias voltage would be wrong and the output transistors could get stressed because of inbalances idle current. Nice video by the way.
Thank you for this video, i have same amp and have that specific problem. It has been on repair for that problem twice. And it is not still fixed. Good to know what to check.
Great Video , where do you order the 2SC2362’s
And
2SA1016’s from
Digikey has minimum order quantity.
Respectfully
Mike
Thanks for another great video. What glue did you select for remounting the electrolytics?
No glue. These caps are small and light enough. They won’t move.
Another concise and informative repair!
hFE on the C3856 is 50 (minimum) according to the data sheet so how is your brand new one coming up with a value of 18?
Really great video. I have a Rotel RB 1070, I haven’t opened it up yet, but do you happen to know if They’ve got fairly similar guts? No worries if you don’t know. My left channel is out, I’ll get around to it shortly.
What I was really hoping to figure out is what you usually use to remove that god damn glue in a relatively easy way? The brown, super degraded glue isn’t an issue, that’s easy enough. But I am constantly running into amps that are just COVERED in it. They might as well have just straight dipped the entire board in it. Do you know any solvents that will eat through it without destroying the board or any components? Or any product that will at least soften it up to make it manageable. I have to catch myself and stop my ocd from taking over because if not I’ll realize I just spent 2.5 hours picking a 3” X 3” section of glue and barely making A dent in it. You either use metal tools and risk damaging the board and components in case you slip, or you use plastic and make it 10x more difficult. Any help would be sincerely appreciated. Thanks !!
Freeze spray can help sometimes. Makes the softer stuff more brittle and bigger chunks come off when you pick at it. If it's not on components, traces or jumpers you can just let it be. It doesn't migrate anywhere.
ISP can also be applied to the glue to soften it. Then use a small pick(got mine from my dentist) to remove the glue.
I have just bought a Peavey CS1000 rack mount power amp... When you plug it in and flick the switch on, the rear panel glass fuse instantly blows.
But looking inside the amp, there is a power board with 2 glass fuses, those arent blown.. It just blows the main rear panel glass fuse..
Ive inspected the board, with my limited knowledge, and found no other obvious faults.. But removed and tested the output T0-3 transistors, and found 4 to be faulted to ground...
Could this be what is causing the main rear panel fuse to blow constantly?!?
I just thought its strange, that the internal power board fuses are still perfectly fine, when it rectifies AC to DC etc... But it blows the mains AC rear panel fuse...
Im really hoping its just the transistors at fault, im new to repairing electronics, and this is my first project. I really dont want my first project to be a failure :(
Check the bridge rectifier in the power supply for shorts across one or more of the diodes.
One of my colleagues gave me a Marantz PM-30 amplifier that does not produce any output whatsoever. He had told me this before giving it to me. I'm a communication electronics technician who normally troubleshoots instrumentation landing systems (localiser, glideslope etc) and this will be my first stint with an integrated amplifier. Wish me luck 😂
Very nice work... and video.
very nice work. how old is the Amp ? what caused all these faults ?
watch the video
How did you pair them(NPN and PNP)?
I have a 4 channel car amp thats immediately blowing the 2 20amp fuses on the amp as soon as its inserted into the holder on the amp, I have only the power cable and the ground cable connected. The remote wire, rc cables and speaker wires are all disconnected. Without even turning the amp on its blowing the fuses... please assist
Зачем убрали rubycon black gate?
I really enjoy watching your videos. Where did you learn to work on electronics?
Nice job, I have an older threshold I am that is in need of some repair. Are you interested?
Potentially. Can you send me details via email (model, history, symptoms) to nick@duality-er.com?
wow i wish i had that kind of knowledge :-) do you know where to find a scemetic of a BLADELIUS MK 2 ? it went in protection mode several times and then also blew a fuse. :-/
Parabéns amigo a sua vídeo aula é bem detalhada !
I got one the same,the left channel get really hot after 20min turn on with no signal going through.
Great job
I have one question do you have a reliable place that you go to to get your schematics on the internet could you possibly speak about that
You can get that from Hifiengine.
Where do you repair guys get the schematics from?
Usually free from hifiengine. I’ve also had to pay for a few from servicemanuals.net
Cool, thanks for the heads up sir. LOVE the channel. Sorry to bombard about schematics. Most people don't respond.@@dualityrepair4770
Excellent, thanks very much.
Where do you get the schematics?
Usually hifiengine
It has a lot of output transistors - is that a good thing?
More output transistors allows for more current. So yes, usually that’s a good thing.
Excellent job. :-)
Thanks
This is my home indeed
Is it me or did that amp use fake Nichicon capacitors ?
No. There genuine Nichicon.
8:27 what about the other transistors?
10:15 what about the BIAS on the other side?
What about the caps on the other side?? It's like replacing car suspension on one side but leaving old on the other
12:07 good job diagnosing
I have Rotel rb 985 Mark 1 the amplifier valume increase Red light blinked.volume down Red light is off . please help me
if you can electronic , then you can show us how to measure """open loop gain of the amplifier""" , then we can say how good you are !!!!!
If you want to criticize someone on the internet using lots of exclamation points as if you’re yelling at them, you should learn English and you should use correct punctuation and grammar!!!!!!!!!!!!!
you should tell us why this transistor is get short , not just open the box and search for short , reason for short that is question , if you want teach out electronic !!
If you want to criticize someone on the internet using lots of exclamation points as if you’re yelling at them, you should learn English and you should use correct punctuation and grammar!!!!!!!!!!!!!
Not always possible to locate the cause after the event. However in this case the open diode would have caused the main output transistors to run hard up against the power rail. This would continue until the weakest output transistor failed from excessive heat. Not all transistors come out of the factory identical and it also means the rest probably should be replaced as they also were stressed out with the heat. Note also the TH601 protection thermistor isnt even physicaly connected to the failed transistors heat sink and so was never able to protect the positive bank.
@@kilgoretrout4461 amen!
To much cables inside.... not good
88.000uf