E-mu Emulator Sampler User Forum for the EIII EII EI and EIII XP

General Category => Drumulator Technical Issues / Tips => Topic started by: lubb on May 19, 2010, 01:37:31 PM



Title: A broken off diode from the PSU diode bridge...
Post by: lubb on May 19, 2010, 01:37:31 PM
Hello,

I have just acquired a Drumulator which normally powers up. But when I looked inside - I from a pure curiosity - I have noticed that one diode from the PSU diode bridge (D13) is partly broken off, only a half of it remains...

I wonder if I can use the Drumulator in such a condition, and what diode type is suitable for replacement...

Many thanks for any help...


Title: Re: A broken off diode from the PSU diode bridge...
Post by: dr.c on May 19, 2010, 03:07:45 PM
Normally, there are four diodes of the same type on a diode bridge....

They are MR501 type. Change THE FOUR OF THEM.


Title: Re: A broken off diode from the PSU diode bridge...
Post by: lubb on May 20, 2010, 08:16:33 AM
Thank You for the first class and prompt support...! Dear dr.c !


Title: Re: A broken off diode from the PSU diode bridge...
Post by: dr.c on May 20, 2010, 11:15:08 AM
Its a plesure !

Change the FOUR diodes, its much better !
Don't make mistakes on the way you mount them ! Take a picture before, send it ! Its a piece of collection !!!!



Title: Re: A broken off diode from the PSU diode bridge...
Post by: lubb on May 24, 2010, 05:30:13 AM
Sadly, i am trying to attach some pictures, but there is an error "upload folder is full...

Anyway, once again, many thanks to dr.c. for his interest and kind help...!!!

Lubos


Title: Re: A broken off diode from the PSU diode bridge...
Post by: dr.c on May 24, 2010, 11:00:11 AM
Put this picture somewhere else, there are a lot of sites for this !
http://www.flickr.com/ (http://www.flickr.com/)


Title: Re: A broken off diode from the PSU diode bridge...
Post by: lubb on May 24, 2010, 12:25:18 PM
http://www.flickr.com/photos/50467876@N05/


Title: Re: A broken off diode from the PSU diode bridge...
Post by: dr.c on May 25, 2010, 01:35:48 AM
Wowwww !!! I never had this !

BE CAREFULL : when you excahnge the diodes, UNPLUG THE MAINS !

THERE ARE LETHAL VOLTAGES ON THE PCB, THE MAINS (110/220 V) TRANSITS THRY THE PCB, BE CAREFULL (I had a "nice" surprise the first time)

AS WELL, do not power the machine with the PCB hanging aroung. The case of the Drumulator is conductive, the plastic of the case is loaded with carbon to make it conductive, wich brings an excellent elactromagnetic shielding as well.

This is true for ALL E-Mu products !


Title: Re: A broken off diode from the PSU diode bridge...
Post by: bedouin on June 03, 2010, 02:48:19 AM
When I first got my Drumulator I powered it on and got a weird buzzing noise.  I opened it up and wiggled those diodes around (I didn't know what they were at the time) and it started working fine.  It wasn't a wiggling actually, but they were mashed up close to one another and I just made them proportionate.  Not sure why that worked, but it's been fine ever since (2 years probably).


Title: Re: A broken off diode from the PSU diode bridge...
Post by: shaun on August 12, 2011, 07:08:15 AM
I got a Drumulator in once where the LM323 has been replaced by a 2N3055. THIS was a real surprise :)


Title: Re: A broken off diode from the PSU diode bridge...
Post by: dr.c on September 03, 2011, 04:12:14 AM
It exploded ? Who was the tech wich did this ? Bin Laden ?