Jump to content


Crown K2 - Heat/Shut down


  • Please log in to reply
1 reply to this topic

#1 AUDollars

AUDollars
  • Members
  • 1 posts

Posted 29 July 2013 - 03:02 AM

Hi all,

I'm very new to this forum. I have read some discussions about the K2's heating behaviour but I did not find a solution to my problem. Pardon me if I missed it...

I recently bought a K2 amp for my HT, it is driving a pair of home JBL speaker (LS80). I did the modification to bypass the sleep system.

Even if it surprised me, this amp goes very hot even for HT use but given what I have read, this is probably normal. However, after some time, one channel shuts down but there are no indicator on, no light that can indicate a overheating problem. Then I shut it down wait a bit to reduce the temp and the amp is then working correctly. However the amp is still shutting down when the temp is again going up. I don't really understand why a channel shuts off and no indicator lights it up (I saw that the leds are correctly working when the amp is turned on).

My amp has space around it even if it is in a furniture (like 5cm free space up and down and 10cm right and left).

Given that issue, I installed a pair of computer fans in my furniture running slowly but given the hot weather these days (even in Belgium we can have hot summer!), the problem comes again. I temporarly increased the speed of the fans and it sounds like it is working but now I can hear them during a movie.

Is there any potential failure in my amp?

Many thanks,

AUD

#2 joust

joust

    Power User

  • Members
  • PipPipPipPipPip
  • 518 posts

Posted 29 July 2013 - 03:56 PM

Bonjour!

The reason that a sleep circuit was incorporated into the K1/2 was precisely for this [heat] issue! Because the BCA amplifier, when on, is always processing/cancelling the carrier wave, hence heat is dissipated (about 250W worth, and it is hot to the touch!). So, Crown decided to add a sleep circuit. Initially, I believe, Crown added a first 6 second delay before the amp can go to sleep. Apparently, some users could detect when the amp was turning on and off and they complained (rightfully!) about this behavior. Then, eventually, Crown issued a Tech Note to increase the sleep delay period, possibly to a max of 1 minute before the amp went to sleep. Some people may have completely removed this protection and then, the amp is always on!
There are some systems inside the K amp that may be susceptible to heat.
Inspect the amplifier visually for faults especially around the output modules; Beware not to tear or punch holes in the Silpad! That's your only protectionn against electrical coupling (via the output module's heatsink: at 100VDC!). I have discovered numerous filter caps with broken solder joints, that eventually will damage your filter cap! If necessary, replace the 8200UF caps, especially if their tops are domed. Look out and resolder all solder connections on the output module, verify the connectors! Then if necessary refurbish the other module and the main boards. Verify also the input level board: I have also seen numerous broken solder connections on the level control leads.
When the refurb is completed: first of all we have to determine if the output module or the main board is at fault. Swap output modules! Then if the symptom is still present, you may want to use a small heat gun and blow heat onto the components until the fault is discovered.
Hope this helps! Try the refurbishment first!

Regards,

Alain