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New member Username: Nyc783Concord, CA USA Post Number: 1 Registered: Oct-11 | Hello everyone... I hope some members will reply who may know the answer to this problem I am having with my Onkyo Integra TX-890 2-channel Tumer-Amplifier (as Onkyo calls it). The unit will power up - stay on. I can use headphones. When I press in either Speaker Selector "A" or "B" the unit shuts down, comes on in a second or two, and if the speaker selector switch is still pressed on, shuts down again and comes on. I have tried testing the unit with the speakers attached and then completely removed. The problem still continues. Does anyone have any idea as to the cause why the unit shuts down when the speaker button is pressed in? I never press both of them in at the same time? I would appreciate any replies. Thank you, everyone. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 16871 Registered: May-04 | . There's nothing specific to point to and, even if there were, I would still suggest you have the unit seviced by a competent technician. On line diagnosis is likely to be mostly guess work which shouldn't send anyone out to buy parts they might not be able to install themself. My first guess would be a bias circuit that has gone adrift. The amp is simply going in and out of protection mode, checking constantly for a corrected signal path before allowing the amp to burn itself to the ground. With the load of the speakers disconnected and the problem still in place this would be my first guess. DC on the outputs might be another cause common to amplifiers that have a few years on them. Though, if you've only disconnected the speakers at the speaker end, there could still be a cabling issue which is causing the amp to shut down. Disconnect the cables from the amp itself and recheck the problem. Make certain not even a single strand of cabling is out of place when you make your reconnects and check the length of the wire for any broken insulation which might cause a short circuit. The headphones are probably driven by a discrete chip amp on this amplifier - not by the main outputs - which would not be affected by the speaker load so that does not enter into the diagnosis. . |
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New member Username: TwochannelsPost Number: 1 Registered: Mar-13 | I have this receiver, and had the same problem. I documented the behavior and solution here: http://www.avrev.com/forum/receivers/6879-onkyo-tx-890-replace-upgrade.html Thus far, I think this problem is caused by an unexpected shutdown when the unit is trying to re-start, such as that caused by an unstable power outlet. My TX890 is plugged directly into a clean filter power stage (Monster Power HTS 2500). This in turn is plugged into the electrical outlet, which is "touchy", resulting in multiple rapid closed circuit events within a short amount of time, if the plug moves even the smallest amount. This outlet has always been this way and has never affected the receiver in prior shutdowns. Maybe there is a component in the receiver that needs replacing, but there is also a practical way to stop the rebooting when the problem occurs. I have since managed to stabilize this outlet. We will see if this solution is long term. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 17748 Registered: May-04 | . What's an "unstable outlet"? What you describe - an outlet unable to securely fasten a simple AC plug - sounds as though it is bordering on the dangerous side of needing to be replaced. A couple of bucks and ten minutes time is better spent IMO than jury rigging a defective component. People can argue for days on end about the value of AC filters and so forth, but it is rather important your AC is being sourced through a secure AC outlet. If you ignore the quality of the receptacle, it doesn't much matter what else you do down the line. . |
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New member Username: TwochannelsPost Number: 2 Registered: Mar-13 | The outlet in question never had the line wires secured. After throwing the breakers for fhe house, I simply tightened the screws and that outlet is now stable. I don't think it was ever dangerous though. For sure others who are experiencing this receiver "re-boot" problem likely have a stable power supply. So the cause is probably something related to a worn component in the protection circuitry. I have since determined if this receiver goes into repetitve re-boot mode, resulting from power disconnect, then one should cycle the amp/pre amp connectors, then apply a load across from the headphone jacks while listening to a music source; I use the smaller portable headphones, I believe they are 32 ohms. This seems to fix the problem. I wish I understood how this computer control circuitry of this amp actually works; but I believe I have found a means to make the receiver usable. |
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New member Username: TwochannelsPost Number: 3 Registered: Mar-13 | I'm getting a new receiver or integrated amp. Good excuse to upgrade my system now. This problem, although can be rectified for the short term, ultimately needs to be fixed, and I don't know anyone who knows how to make this repair. Not sure what to do with this heavy paperweight. Best regards to everyone! |