Intermittent hic-up on power on

Good afternoon all. Not a major issue but would like to know if this is a known issue. I have a strict switch on routine (1) Media player. (2) Tone match. (3) Power stand. Every now and again after switch on I see that the display is reading level from the 2 microphones but there is no sound coming from the array or bass unit. I then switch off, then switch on again in sequence, this always seems to work then no further problems.

Regards

Garry  

I have always gone the other way and never experienced any issues: Power stand on>check all channels on ToneMatch are muted and gains are minimised and vol pots are minimised>turn on ToneMatch>then un-mute mics>turn on media player and and then un-mute it's channel.

This way around if for any reason any of the devices has a "audio thump" at initiation or power up - it's never going to be amplified or go out through any speaker.

Hi Garry,

Garry posted:

Good afternoon all. Not a major issue but would like to know if this is a known issue. I have a strict switch on routine (1) Media player. (2) Tone match. (3) Power stand. Every now and again after switch on I see that the display is reading level from the 2 microphones but there is no sound coming from the array or bass unit. I then switch off, then switch on again in sequence, this always seems to work then no further problems.

Regards

Garry  

It sounds like your power-up sequence is fine. Please contact Bose L1® Support in the UK about the intermittent need to restart the system.

Thanks,

ST

Hi Garry,

I occasionally experience this issue with at least one of my T1 units. (I'm fairly certain that I've only experienced it with my main gig unit; I own 4 T1).

Once in a while after power up there is no output from the T1 just as you have described. The weird part is that I usually have a gut feeling that it won't work as I power it up, so, I un-mute a channel and sure enough I need to power cycle it and then it works fine.

At the end of a gig I mute all of the channels and then I power down the power stand but I always leave the T1 power switch in the on position. At the next gig the T1 powers up automatically with all channels muted when I power up the power stand. This works well for me and has no bearing on the issue we occasionally experience with our T1, it is just how I choose to operate as it does not cause any power up noise in the L1 M2 speaker... This is also how I power cycle the system when I encounter the no sound issue.

This particular T1 is probably not under warranty; I guess I should check. I'm going to start documenting the occurrence of this issue should it happen again. It's never been a show stopper and I always have a spare T1 and a spare power stand with me.

I don't know if the issue lies with the T1 or the power stand since this happens with the digital connection (the issue could be in the power stand's digital input). I tend to always use the same T1 and power stand for my solo and duo gigs. The other units are used mostly when I provide sound reinforcement for a friend of mine at her gigs in schools.

I'll report back should I have more information.

Mark

Hi Garry,

As luck would have it, I experienced the same issue at my gig this afternoon. I suspect that the issue lies with the L1 power stand (model II in my case) after performing some trouble shooting as follows:

  1. I power cycled the T1: still no output
  2. I then connected the analogue Master out from the T1 to the analogue input on the power stand: still no output
  3. I then disconnected the digital EtherCon cable from the T1 at the power stand and connected it to the external T1 power supply with the analogue cable still connected: still no output
  4. I power cycled the power stand: we now have output!

I don't recall if I had kept the analogue connection with external power supply at the time I power cycled the power stand (I think so) and subsequently reconnected the digital connection and removed the analogue cable or not... but I did remove the analogue connection and external power supply to run digitally for my otherwise trouble free gig.

In hindsight, I wish I had performed these additional tests:

  1. swapped in my spare T1 before I power cycled the power stand to test for output
  2. tested the T1 with my other power stand

 

I suspect that the power stand contains a "power up Mute circuit" that occasionally is not un-muting after the power up delay time has passed. This type of circuit may use a traditional relay (mechanical fault) or it may a semiconductor type circuit (faulty component) or possibly be DSP based (possible software glitch). I'm troubleshooting in my head as I write this and I'm probably loosing most of you reading this as my day job is repairing professional audio equipment including large format digital consoles (the really expensive stuff...). If my suspicions are correct regarding where the intermittent fault lies, we would need to send our power stand to a Bose Repair facility to have it corrected. 

I have another gig on Saturday, if luck is on our side the glitch will reoccur and I can then perform the T1 swap and possibly the power stand swap although the T1 swap would likely suffice for me to arrive at a conclusion. 

For what it's worth, today was a cool day which rules out a heat related issue.

I will report back once I have more information...

Mark

Thank you all that have taken the time to read and reply to my post. All comments and suggestions are noted, printed and stored in the folder for reference.    

This exact thing just started happening to my L1. I have sent the power stand in for an "out of warranty" repair 😞

 

Should be back in 2 weeks or so.