Does my amp have a software bug?

[admin_exported]

Hi, do stereo amplifiers have software bugs? I have had this strange problem with my Marantz PM7004 since I bought it. My English is not so good, but I hope that you will understand what I mean.
The problem is turning it on from standby. If I press the power button on the remote control everything is OK - I hear a relay sound, the led indicators light on, then in a few moments after another relay sound it's ready. But if I use the input selector knob on the front panel to turn it on, after the first relay sound the leds just blink for a moment and it shuts down. Then I have to turn the knob a second time. This happens 99% ot the time and only if the amp has been in standby for more than 30 min. I have never payed much attention to it, but suddenly 2 days ago I was struck by an idea - A SOFTWARE BUG IN THE AUTO STANDBY FUNCTION. This function (which I have enabled since day one) is supposed to turn the amplifier off if there is no sound for about 30 continuous minutes. My thought was that maybe the timer doesn't reset properly when I turn it on using the input selector knob or something like that. So I disabled it and since then (5 or 6 times) everything is OK. It starts as it is supposed to - both using the remote control and the input selector knob.

So, my question is have you other Marantz users here noticed such behaviour with your amplifiers? Can you try to reproduce this issue by enabling the auto standby function? You can enable or disable it by holding down the Source Direct button on the front panel - if the little red standby led blinks 3 times it means that you have just enabled it. If you repeat the process it will blink only once, which means that you have disabled it.

 

[Overdose]

If your amplifier is still under warranty, I would advise speaking to the retailer that sold you the amp.

 

[Andrew Everard]

As far as I know, that's how the auto standby is supposed to work. To bring it out of auto standby you need to press either the standby button on the amp or the corresponding one on the remote handset - operating the input selector presumably wakes up the control processor and it then waits for a further instruction.

 

[Anonymous]

It doesn't have a dedicated standby button. The button under the input selector is a physical power switch. Also according to the user manual to turn the amp on from standby mode one has to either use the power button on the remote control or the input knob on the amp. But I think that you are right. Maybe the knob does not send a real "power on" command like the remote does, but rather does the same thing as when the amp is running - sends a signal for input source change. Then, since the unit is not running, the result from this command is waking it up. So at this point the microprocessor doesn't know that this is actually a new run session and continues to work from the last point. It then detects that it's been more than 30 minutes since the last sound and instantly activates the auto standby. If that's the case then it means that the behaviour I am experiencing is not a problem, but rather a design flaw. They have found an easy way to use the input selector knob for waking the device, instead of putting a dedicated standby button, but haven't taken in mind that this way the auto standby function will not be reset and will activate. All of this may be nonsense and that is why I am asking other Marantz users here if they experience the same behaviour from their amps. If I am right and this is a design flaw I believe that the PM7004 will not be the only affected model.