Crown Macrotech 2402 odep issue

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     Had a bit of a weird issue with one of my trusty old Crowns (well, Amcron actually) earlier, I switched on and noticed that the odep indicator on channel 2 wasn't lit, I powered back off and disconnected the speakers in case something had shorted but the odep light remained off when I powered back on. I then passed a signal through the amp and the signal/IOC indicator was working as normal so took a chance and re-connected the speakers and found that audio was being passed perfectly well.  Now the funny part, after a minute or so the odep indicator lit up dimly and slowly got brighter, coming up to full brightness after 30 seconds or so, all the while the channel was passing audio just fine. I left it running for a while at a moderate volume and all now seems to be ok. 
 I'm pretty sure that the amp needs to go to the menders but am I going to damage anything by carrying on using it for a while as I have a busy few weeks coming up?  
 Also, I've just remembered that over the last few weeks the amp, if not used for a few days, will pop through the speakers when first switched on, I put it down to a dirty/sticky relay but it may be related?
 Another thing; I didn't have a meter with me earlier but I can check for dc offset when I'm back at the venue tomorrow.

Edited by njw - 22 July 2022 at 11:37pm

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njw Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 March 2010 Location: S. Wales Status: Offline Points: 2574	Post Options Post Reply Quote njw Report Post Thanks(0) Quote Reply Topic: Crown Macrotech 2402 odep issue Posted: 22 July 2022 at 11:34pm
	Had a bit of a weird issue with one of my trusty old Crowns (well, Amcron actually) earlier, I switched on and noticed that the odep indicator on channel 2 wasn't lit, I powered back off and disconnected the speakers in case something had shorted but the odep light remained off when I powered back on. I then passed a signal through the amp and the signal/IOC indicator was working as normal so took a chance and re-connected the speakers and found that audio was being passed perfectly well. Now the funny part, after a minute or so the odep indicator lit up dimly and slowly got brighter, coming up to full brightness after 30 seconds or so, all the while the channel was passing audio just fine. I left it running for a while at a moderate volume and all now seems to be ok. I'm pretty sure that the amp needs to go to the menders but am I going to damage anything by carrying on using it for a while as I have a busy few weeks coming up? Also, I've just remembered that over the last few weeks the amp, if not used for a few days, will pop through the speakers when first switched on, I put it down to a dirty/sticky relay but it may be related? Another thing; I didn't have a meter with me earlier but I can check for dc offset when I'm back at the venue tomorrow. Edited by njw - 22 July 2022 at 11:37pm

njw Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 March 2010 Location: S. Wales Status: Offline Points: 2574	Post Options Post Reply Quote njw Report Post Thanks(0) Quote Reply Posted: 23 July 2022 at 7:13pm
	Just switched the amp on, no popping sounds today however the odep indicator was dim for about five seconds before coming up to full brightness, I measured the dc offset and have about 0.001v on both channels.

kedwardsleisure Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 20 January 2009 Location: Staffordshire Status: Offline Points: 4949	Post Options Post Reply Quote kedwardsleisure Report Post Thanks(0) Quote Reply Posted: 24 July 2022 at 5:32pm
	I made a note of this somewhere, check the flywheel diodes on the output board of the faulty channel, I had one some years ago that had exactly those symptoms including the little pop, it was a leaky diode that wasn't leaky enough to pull the offset away once the amp was through the unmute and enable period.
	Kevin North Staffordshire

njw Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 March 2010 Location: S. Wales Status: Offline Points: 2574	Post Options Post Reply Quote njw Report Post Thanks(0) Quote Reply Posted: 25 July 2022 at 11:36am
	Thanks Kev , also, the amp is actually a 2401 not a 2402 as mentioned if that makes any difference?

kedwardsleisure Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 20 January 2009 Location: Staffordshire Status: Offline Points: 4949	Post Options Post Reply Quote kedwardsleisure Report Post Thanks(0) Quote Reply Posted: 25 July 2022 at 12:28pm
	dont think it matters, the 2402 has the vz-style power modules
	Kevin North Staffordshire

EmPro Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 26 June 2020 Status: Offline Points: 766	Post Options Post Reply Quote EmPro Report Post Thanks(0) Quote Reply Posted: 16 May 2023 at 6:48pm
	This reminds me of one of my MT1200 bouhgt as faulty..ch1 odep light off....so..i started with vcc on output..nothing...just couple of mv...as the working ch...then the supply...all good...the outputs all good...the odep etc etc all good....i pass signal to the ch...comeing out cristal clear....the odep red led still off....i was scratching my head for another hour to double check everything to find in the end the damn RED LED odep indicator burnt i was laughing and crying at the same time 3 hours lost for a faulty led
	EmPro Audio

knet94 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 31 March 2008 Location: NW London Status: Offline Points: 1510	Post Options Post Reply Quote knet94 Report Post Thanks(0) Quote Reply Posted: 16 May 2023 at 9:47pm
	I had a 2401 with the ODEP light not coming on. Proved to be a faulty bulb. Think a new one cost about £0.80p.

EmPro Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 26 June 2020 Status: Offline Points: 766	Post Options Post Reply Quote EmPro Report Post Thanks(0) Quote Reply Posted: 16 May 2023 at 10:43pm
	I fitted some blue diffused led-s insteed of red ones looks way better Edited by EmPro - 18 May 2023 at 11:03pm
	EmPro Audio