2. amps-preamps
  3. 1130114682

WHAT WOULD CAUSE JC-1 MONOBLOCK TO SELF DESTRUCT?

Hi all,
I own Parasound Halo JC-1 monoblock amps, and have never had any reliability issues at all with them.
I have a friend, however, who had a JC-1 monoblock to literally self-destruct.
He said he was listening to it at normal levels, and heard a loud pop that almost sounded like a firecracker went off, the amp went completely dead, and the smell of toasted components filled the air.
He shined a flashlight through the top cover and said that it looked like at least 8 to 10 of the black square Sanken transistors mounted on the sides of inside of the amp, on the heat sinks, had literally blown to pieces!
He said the Sanken devices were still there, but the centers of many of them had literally blown out.
I would assume that these square black Sanken devices are the output transistors?
He checked the power cord, speaker cables, speakers, interconnects, etc., for short circuits and found nothing!
Has anyone else out there had this to happen to their Parasound Halo JC-1 monos, or any other amp before?
What would cause such an incident to happen?
Any answers, ideas, or help would be greatly appreciated.
Thanks a million!
Angela
audio_girl
parasound
1 posts
 
Why don't you contact the tech dept at Parasound?
The techs with the most JC 1 experience are Tony Pointes at 415 675-7273 7am to 2pm or Bob MacDonald at 415 675-7274 10am-5:30pm.
Tell them the serial no. of the unit.
Richard
dill
2,484 posts
 
Ask John Curl, he is a regular here. http://www.audioasylum.com/audio/general/bbs.html
metralla
945 posts
 
Thanks for posting, Richard.

Regards,
matrix
305 posts
 
First thing I came up with was one transistor not up to par, before reading all of the posts. can almost guarantee thats really the only thing capable of that unles a ground or power wire came lose and shorted, but common whats the chances of that? It had to be a shorted transistor from overheat or something, maybe not in perfect contact with the heatsink, they use a grease kinda stuff to make contact, something happend.
audio_girl OP
91 posts
 
Guys,
Thanks for all your replies!
My friend has his JC-1's plugged directly into dedicated outlets.
Unfortunately, he bought the units used about 15 months ago, so there is no warranty on them.
He did have this amp repaired by Parasound in July 2005.
He accidently dropped an interconnect on the speaker cables where they exit the amp, and it caused a short circuit and they had to replace all the output transistors, mosfet drivers, fuse, some resistors, emiter diodes, etc.
This time, however, he did nothing wrong...the amp just self destructed.
He also said that the amp hadn't acted completely normal since it was repaired. He said it would shut itself off occasionally for a few seconds, then resume normal operation. He said when it would do this the blue halo light around the power on button would turn red.
He said this would happen up to 4 times per hour on certain days, and was totally unpredictable.
Thanks again for all of your responses!
Angela
More to discover