Power surge burnt my stereo amplifier?!

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Hy!

I am haviang a Pioneer A-602R Stereo amplifier!
Now two days ago I was on the net and while in a game I herd a sound in my amplifier that described is as if someone would mistakenly drop a PC screw into it , and afterwards there was no more sound!
I turned the amplifier off and restarted it 20 seccond later with the volume knob to the minimum set... still no sound! I switched speakers set, still no sound.
I switched to another source got the volume up to the middle and only at very near listening with the ear to the speakers there was sound at the surface on each source I comuted to.
Afterwards I disconected the speaker cords and done as following! Pulled out the source cable connecting the PC to the amplifier out of the amplifier and connected speakers A and B, and switched to the CD imput with the CD Player amplified to it, and went with the volume all the way to the maximum, when at one moment reaching maximum a relay decoupled inside, moved the volume all the way down and the relay coupled! Done the same on all other sources, volume up and down and the relay did not switch off no more!
What could it be? If it is the 96khz spike that comes from the internet as I heard that burt it what should I do? What type of external audio card should i buy? One of those usb sticks audio cards? One of those DAC type audio cards?
Is this fix expensive?
What should I watch out for in the future for?
How should or how should I connect the Ground from my amplifier and to what?
Would that help a little too? What with?
Thank you!
 
So on one hand you say that the Pioneer is a robust amplifier and on the other hand you say that it's more sensitive?
Not at all. By things, I mean just that. A television is more likely to fail than a toaster from a surge. So it is possible that a surge would only damage one item. However, just because his amplifier is twenty years old does not mean it died of old age.
 
Oszkar, do you have DC on the speaker outputs? More than a tenth of a volt or so is bad news.
If by contrast, a twenty year old electrolytic cap shorted and blew a rectifier resistor or fuse, you may have a much easier time of it.
See this thread for old amp repair instructions: http://www.diyaudio.com/forums/solid-state/136261-vintage-amplifier-repair-upgrade-manual.html
I find electronic equipment built before the MOS surge supressor was cheap, or cheaply built enough afterwards not to have one, to be more sensitive to power surges than resistance heaters and incandescent light bulbs. Most of the power surges we have in the states are caused by lightning. Systems with a local low-tech generator have a much less stable AC supply, especially if the local generator is switched in or out of the supply.
 
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PIONEER A-602R A-702R SM Service Manual free download, schematics, eeprom, repair info for electronics
This design has microprocessor control of its major functions, switching, volume control etc. That means there is little point saying try this or that possibility if you cannot clear the fault settings which should have removed connections into and out of the amp and prevented serious damage. There is the possibility with power removed from the micro, and if there really was an almighty surge (And it would need to be the magnitude of a nearby lightning strike) that the programming is erased or corrupted.

Unless you have experience with microcontrollers and amplifier problem solving, don't mess with this without a lot of close support, if any is actually available. This is the job of a qualified or very experienced technician who knows these protection systems.

What was your approximate volume settings on a scale of loudest down to late night listening level and the total number of speakers and their nominal impedance values?
 
Ian Finch

The volume was soft quiet there was no lightning as the weather has been just coming back to normal and the sound that I heard inside it was as dropping a screw into a computer case when mounting a drive into your PC, the speakers I had on were messured on a scale of 200 ohm with a multimeter, one at 6.8 ohm and one at 7.0 ohm
 
You need a power conditioner with surge protection.... Monster power and Panamax have very good ones.

Thx-RNMarsh

You can install one right in your service box. It pops right in just like a dual pole circuit breaker. They're very common, actually. It's practically a necessity in some communities, depending on what you share electrical service with.

Surges are more common than you think. Remember that overloading one phase raises the voltage on the other phase. That phase could be overloaded next door or a mile away and still raise the voltage on one phase of your service.

The vast majority of modern electrical devices are relatively immune to small and/or transient surges. But you can see them if you have incandescent lights burning.
 
Your speculation is probably correct. Contrary to popular belief, the internet can and often does kill amplifiers. It sends audio viruses straight into the power transistors.

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Another victim down.
 
I was thinking so aswell since dvds have upsampling frequencyes that go into your amplifier
The fact is that I talked to a serviceman and said that he encountered this problem to many folks on many amplifiers that got to him into service for them to be.
I had many other and still have old equip. that don't suffer but this one, kept next to pristine...?!
Aniway even if it dyes I am keeping it for it was one of my most beloved models of all time... Roundy, heavy and powerfull
If my serviceman can get it up and running, I am thinking of placing a 18cm pc fan ontop to pull air out because Pioneers as always known in theyr history tend to get hot even when no workload is applyed
 
Now don't get me wrong... I am talking about signals that could cause alternace in the electrical signals and once sent to the amplifier could be an overload and burn something like an input selector or something in the stage or some why not capacitor or transistor of the amplifier...
 
what's all this nonsense about "audio viruses" and ultrasonic leakage from network audio sources?.... just that... somebody is pulling your leg..... that said, i actually have seen two Sony receivers that had DAC filters go bad, and allow sampling noise through to the audio amps, causing the amplifiers to draw excessive current, but it's an extremely rare occurrence, as i have serviced hundreds of Sony receivers in the last 5 years, and only seen this happen twice. the way to detect it (in an otherwise normally functioning receiver) is to run the receiver with a 100W incandescent bulb in series, and power up the receiver with no loads attached. then turn the volume control up to maximum with the receiver in surround mode, and see if the amp begins drawing excessive current (the bulb will go from dim to bright). if it draws excessive current, the DAC filters are letting ultrasonic noise through, and you should replace the electrolytic caps in the DAC filters. again, this is extremely rare. and no amount of sampling noise from a virus or other malfunction in a sound card, etc... should be making it past the input switch and volume control. analog circuits generally roll off above 20khz, and the ADCs in the receiver chop off anything above 22 or 24khz (because it's above the Nyquist limit) when analog signals are routed through the DSP. i would look for more common causes of amp failure, such as dried out caps in the low voltage analog supplies, or a bad bias transistor, or even dried out heat sink grease on the output devices.

i have never seen the DAC filters bad in a Pioneer receiver, and i service several per day...... but here the subject is an integrated stereo amp with no DSP.

check C213, 214, 231, 232, 235, and 236 to see if they have high ESR.....
 
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