Onkyo TX-SR805 slight problem...

[Katzie]

As in slight problem... I mean I was a dope and kind of... well I think fried it. That said, I have this the Onkyo TX-SR805 Reciever. I'd post a link, but this is my first post.

So... story is, I have my awesome little receiver there, hooked up to a set of Polks. The Polks, are also hooked up via a second set of speaker wire to another pre-amp / amp setup. Well, the pre-amp/amp setup was on, and the Onkyo was off. I turned on the Onkyo, and whattya know, POOF there goes smoke coming from the Onkyo. Luckily, the pre-amp/amp setup was unharmed... somehow

Can I fix this myself, or do I have to send the unit off to get fixed by a pro? Thanks.

And yes, I am a tool

 

[TLS Guy]

As in slight problem... I mean I was a dope and kind of... well I think fried it. That said, I have this the Onkyo TX-SR805 Reciever. I'd post a link, but this is my first post.

So... story is, I have my awesome little receiver there, hooked up to a set of Polks. The Polks, are also hooked up via a second set of speaker wire to another pre-amp / amp setup. Well, the pre-amp/amp setup was on, and the Onkyo was off. I turned on the Onkyo, and whattya know, POOF there goes smoke coming from the Onkyo. Luckily, the pre-amp/amp setup was unharmed... somehow

Can I fix this myself, or do I have to send the unit off to get fixed by a pro? Thanks.

And yes, I am a tool

We seem to have an outbreak of this problem. You CAN NOT and MUST NOT connect one set of speakers to two amps, whether one amp is on and the other off.

You have fried at least the output stages of the Onkyo and may be a lot more. Unless you are skilled and have equipment, you will not repair this your self. I doubt this is the case or you would not have caused this problem.

At the purchase price of this receiver, repair is probably not warranted. It likely will be cheaper to just buy a new receiver.

If you send it in for service, you won't know how much time it will take to find the extent of the damage and repair it. Your bill could conceivably be more than the purchase price. In a situation like this, damage is likely to be extensive and severe.

 

[Katzie]

Yeah.. figured as much. Thanks for the info!

 

[afterlife2]

You can also look on ebay for the board it's pretty easy to install and lots of info online on how to install it. Make sure you disconnect AC before install anything to the receiver. Meaning connecting wires plugs or anything else. Also you might also wanna buy a laptop cooler to put on top of the reciever to keep it cool: http://www.amazon.com/Laptop-Notebook-Cool-Pad-Fans/dp/B0030B2O3M/ref=sr_1_10?ie=UTF8&qid=1333803492&sr=8-10 PM me if you need help.

 

[TLS Guy]

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You can also look on ebay for the board it's pretty easy to install and lots of info online on how to install it. Make sure you disconnect AC before install anything to the receiver. Meaning connecting wires plugs or anything else. Also you might also wanna buy a laptop cooler to put on top of the reciever to keep it cool: Amazon.com: Laptop Notebook Cool Pad w/ 3 Fans: Computers & Accessories PM me if you need help.

The problem is we don't know if this went back to the power supply regulation board.

I would assume the preamp, processor, HDMI and switching circuits are OK.

So if he changed the amp board, he would need to check the voltages to the amp board before connecting.

Since it smoked you can be certain there is more damage than just the power transistors. The affected amp channels have likely lost the drivers, some diodes and resistors along with the power transistors.

What I would do, is disconnect the power amp board, then check for blown fuses, I bet there are some. Replace them and then check the supply voltages including under load. Then I would remove the power transistors from the channels connected the speakers with the added power amp connection. I would look for and remove burnt resistors, and check the rest. I would carefully check all diodes in the driver and output stage and then test the driver transistors.

The replace parts as necessary and bring it back up slowly on the Variac.

If the power supply flunked, I would trouble shoot that.

After carefully bringing it back up and making sure nothing blew and it was stable, then I would run test signals though it and test it on the scope, and then test distortion to make sure it was within spec.

The quick way is to find and amp board, but the power supply needs checking as otherwise he might return to square one.

One other thing: since that is a modern unit, it is very likely that the phase splitter/driver stage is one integrated circuit per channel. That is why it is important to have a circuit, to see how things work and the lie of the land. Unfortunately Onkyo and other manufacturers will not release the circuits of their units. That makes life almost impossible. Back in the day units generally came with circuits in the user manual!

 

[Grador]

To paraphrase TLS Guy, are you looking to have a working amp or a long term hobby?

 

[CDogg]

I would buy another receiver instead of sinking money into the unknown. You will be doing your wallet and bank account a favor.

 

[tattoo_Dan]

As in slight problem... I mean I was a dope and kind of... well I think fried it. That said, I have this the Onkyo TX-SR805 Reciever. I'd post a link, but this is my first post.

So... story is, I have my awesome little receiver there, hooked up to a set of Polks. The Polks, are also hooked up via a second set of speaker wire to another pre-amp / amp setup. Well, the pre-amp/amp setup was on, and the Onkyo was off. I turned on the Onkyo, and whattya know, POOF there goes smoke coming from the Onkyo. Luckily, the pre-amp/amp setup was unharmed... somehow

Can I fix this myself, or do I have to send the unit off to get fixed by a pro? Thanks.

And yes, I am a tool

just out of curiosity , what were you trying to accomplish by connecting two rcvr/amps to one set of speakers ?

 

[TLS Guy]

just out of curiosity , what were you trying to accomplish by connecting two rcvr/amps to one set of speakers ?

This is the second guy who has done this in about a week!