ESL Series Purity Black going into auto-protect mode

[pit]

Hi MLOs,
Asking for a little help in troubleshooting why one of my purity speakers is going into auto-protect mode. I've had the speakers since 2011 but until recently when I bought the Pioneer receiver have I actually started to use them. I'm running them in 2.1 setup, which worked perfectly for about a week, but now one of them is going into auto-protect mode after 10-15 minutes of listening at normal level. I unplug is as the manual states and can listen again for a short time until it goes into auto-protect mode. I don't have any problems with the other speaker. Im afraid its the built in amp thats failing and will have to be replaced. I unfortunately didn't register the speakers so I'm not covered by the 5 year warranty. My current setup is listed below.

Appreciate any input.

Thanks

pit

Pioneer SC 79 Receiver
MartinLogan ESL Series Purity Black(speaker level connection)
BIC PL-200 Acoustech Platinum Series Subwoofer
C&E CNE62270 12AWG Speaker Wire Cable

 

[Gordon Gray]

I assume you've checked to make sure it's a speaker problem and the issue is not elsewhere.

Likely suspect / power supply board.

 

[Nutshell]

Are you sure it is an auto protect? Isn't it automatically going into standby? This happens with the Purity when it receives no signal. Maybe you could try with some louder levels for a while, just to be sure what is happening.

 

[pit]

Im sure its going into auto-protect, play it a different levels and it does the same. I called ML and was able to speak to Chris who stated that the speaker might be drawing too much power. He emailed me a fix instructions which shows that I need to cut a diode. I'll will try that when I get home, I'll update this post with my results.

Thanks

 

[pit]

Just like to update this thread and state that the diode fix cleared the issue. I've been using them throughout the weekend and the speaker has not gone in auto protect. Simple fix and glad it wasn't a faulty power supply.