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-   -   Behringer Europower PMH1000 blown psu fixed (http://www.diyaudio.com/forums/power-supplies/220152-behringer-europower-pmh1000-blown-psu-fixed.html)

slideman82 22nd September 2012 12:30 AM

Behringer Europower PMH1000 blown psu fixed
 
I have just repaired its power supply for second time, and I'm still listenning some kind of rattle around switching power mosfets (replaced blown 17n80 with IRFP450's and reversed cooler fan for better cooling). Is this normal?

slideman82 1st October 2012 07:45 PM

Is this normal?

nigelwright7557 2nd October 2012 11:42 PM

If it keeps blowing up then something is wrong or you are driving it too hard.

Zero Cool 3rd October 2012 12:18 AM

There is a problem with the amp module on some of these that use the switching amp section. it seems when Behringer stole the design from Yamaha they neglected to duplicate the board layout. The output transistor will arc over and char a path from one leg to the next. sometimes through the middle of the board. IF...this is the case. then when the transistor arcs over, it kills the power supply. often times it kills the amplifier too! can't remember what model that is however.

slideman82 3rd October 2012 02:12 AM

Huh, what a problem! But... this kinda rattle I hear could be an arc over transistors? First time I repaired it (I didn't change the TOP221 ic, and some hours of use later switching power transistors blew up, and some other things I changed then) there where no rattle...

It's a big help, btw! Thanks!

musiccankill 13th October 2012 12:58 PM

Hello..!
I have got a pmh1000 with a blown power supply 2..
At first i could only see (also checked with component tester everything on the board) a tottaly fried DIODE (D24 smd) i replaced it with a 1n4007 and powered it up without anything connected (mixer or amp)..
It started working and i could hear a buzzing sound from the power supply...
I left it on for 3-4 seconds...
Then i connected the mixer and it worked grat for another 3-4 seconds..
Then i also connected the power amp..
Left it on for 3-4 seconds and i could hear a buzzing sound from the speakers too...(as loud as the music)...
The after i checked for pieces that may have warmed up (there were nothing heated) i turned it on and left it playing...
I knew the buzzing was not ok but i left it on..
~30 seconds later, it blew up (no popping sound on speaker)
Just a sparkle from the power board and the fuse blown..
I checked the power board and the 4 resistors after the power bridge along with the 17n80c3 mosfets are blown up (haven't seen anything else blown till now)...
Thanks god the power amp is still not fried (checked it again with component tester and everything seems ok...)
Any help here?
Thanks

Fergytron 26th October 2012 02:41 PM

Check the electrolytics for any leakage or pooching.

slideman82 29th October 2012 05:01 PM

Quote:

Originally Posted by musiccankill (Post 3199962)
Hello..!
I have got a pmh1000 with a blown power supply 2..
At first i could only see (also checked with component tester everything on the board) a tottaly fried DIODE (D24 smd) i replaced it with a 1n4007 and powered it up without anything connected (mixer or amp)..
It started working and i could hear a buzzing sound from the power supply...
I left it on for 3-4 seconds...
Then i connected the mixer and it worked grat for another 3-4 seconds..
Then i also connected the power amp..
Left it on for 3-4 seconds and i could hear a buzzing sound from the speakers too...(as loud as the music)...
The after i checked for pieces that may have warmed up (there were nothing heated) i turned it on and left it playing...
I knew the buzzing was not ok but i left it on..
~30 seconds later, it blew up (no popping sound on speaker)
Just a sparkle from the power board and the fuse blown..
I checked the power board and the 4 resistors after the power bridge along with the 17n80c3 mosfets are blown up (haven't seen anything else blown till now)...
Thanks god the power amp is still not fried (checked it again with component tester and everything seems ok...)
Any help here?
Thanks

Check the output transistors, could be that. I hate these PMH1000... it failed all around the world!


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