Doepfer

Wondering if Dieter or anyone can help with this one:

I've had 3 G6 racks for a couple of months. None of them have been problematic until 
yesterday, when one of them blew a fuse. I replaced the fuse, and everything worked 
again, until today, when the fuse blew again. I removed most of the modules, and the fuse 
blew. I removed all of the modules, and a fuse blew. I then tested one of the other cases 
by turning it on a few times, and eventually one of those blew too. I have tried different 
surge protectors, different cables, different electrical circuits in my apartment -- same 
thing.

It would seem that this would indicate either 1) some major problem with my building's 
electricity (possibly but unlikely), or 2) two G6 power supplies that went defective at 
exactly the same time (possibly but unlikely).

Any thoughts? If it is some crazy problem with New York city's electrical grid, I would 
imagine the Doepfer racks wouldn't be the only things susceptible. But the fact that two 
different boxes, tested with all different numbers of modules (none, a few, a bunch, and a 
lot) kept blowing seems downright weird.

I am using 1/2 amp slow-blow fuses, and tested the outlets in the apartment, which are 
all running pretty close to 115v (~117, ~120, etc.).

Is there something completely stupid and obvious that I'm missing?

Thanks anyone for any help.
Michael Tritter
New York City

Michael,

really strange that the problems occur after a couple of months and with
several systems at the same time. Here is my suggestion (I assume that your
A-100 frames include PSU2 with the toroid transformer):

The 500 mA value is based on the recommendation by the the manufacturer of
the transformer. Though it never happened in our company we've been told
that the 500 mA fuses blow now and then during power on because of the
transient current (never while the unit is on for a while). That's why we
increased the recommended fuse value to 630 mA in the meantime (315 mA for
230V systems). I'd recommend to replace the fuse by 630 mA or the next value
you can get (even 750 mA would be OK). The value is not that critical as in
case of a short circuit even a fuse with a slightly higher value will blow.

And it's essential that a slow blow/time lag fuse is used. Fast or medium
fuses will blow during power on because of the transient current.

Best wishes
Dieter Doepfer

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von michaeltritter
> Gesendet: Mittwoch, 6. September 2006 06:03
> An: Doepfer_a100@yahoogroups.com
> Betreff: [Doepfer_a100] g6 fuse problems
>
>
> Wondering if Dieter or anyone can help with this one:
>
> I've had 3 G6 racks for a couple of months. None of them have
> been problematic until
> yesterday, when one of them blew a fuse. I replaced the fuse, and
> everything worked
> again, until today, when the fuse blew again. I removed most of
> the modules, and the fuse
> blew. I removed all of the modules, and a fuse blew. I then
> tested one of the other cases
> by turning it on a few times, and eventually one of those blew
> too. I have tried different
> surge protectors, different cables, different electrical circuits
> in my apartment -- same
> thing.
>
> It would seem that this would indicate either 1) some major
> problem with my building's
> electricity (possibly but unlikely), or 2) two G6 power supplies
> that went defective at
> exactly the same time (possibly but unlikely).
>
> Any thoughts? If it is some crazy problem with New York city's
> electrical grid, I would
> imagine the Doepfer racks wouldn't be the only things
> susceptible. But the fact that two
> different boxes, tested with all different numbers of modules
> (none, a few, a bunch, and a
> lot) kept blowing seems downright weird.
>
> I am using 1/2 amp slow-blow fuses, and tested the outlets in the
> apartment, which are
> all running pretty close to 115v (~117, ~120, etc.).
>
> Is there something completely stupid and obvious that I'm missing?
>
> Thanks anyone for any help.
> Michael Tritter
> New York City
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>

--- In Doepfer_a100@yahoogroups.com, "michaeltritter" <mtritter@...> wrote:
>
> Wondering if Dieter or anyone can help with this one:
> 
> I've had 3 G6 racks for a couple of months. None of them have been problematic until 
> yesterday, when one of them blew a fuse. I replaced the fuse, and everything worked 
> again, until today, when the fuse blew again. I removed most of the modules, and the 
fuse 


Hi Michael,

I had a problem with a G6 that turned out to be only visable after I removed all the 
modules and looked closely at the power supply. 

My unit had the old power supply and a part had melted. I was blowing fuses non stop and 
couldn't figure out why. If you want to know which part the archives might mention it. 
-could have been the transformer. Once I installed the PS2 or whatever the bigger/later 
version everything was fine. 

TD, NYC as well!

Dieter & Tommy...
Thanks for the advice. There is definitely something weird going on as the different boxes 
are both blowing fuses and they both have the newer power supply. I've plugged and 
unplugged just about every combination of modules to no avail.
I am getting ahold of .75 amp fuses to see if that fixes the problem. If not, perhaps some 
sort of ritual to remove evil spirits. This is weird.
Michael


--- In Doepfer_a100@yahoogroups.com, "Tommy DOG" <mrsvomit@...> wrote:
>
> --- In Doepfer_a100@yahoogroups.com, "michaeltritter" <mtritter@> wrote:
> >
> > Wondering if Dieter or anyone can help with this one:
> > 
> > I've had 3 G6 racks for a couple of months. None of them have been problematic until 
> > yesterday, when one of them blew a fuse. I replaced the fuse, and everything worked 
> > again, until today, when the fuse blew again. I removed most of the modules, and the 
> fuse 
> 
> 
> Hi Michael,
> 
> I had a problem with a G6 that turned out to be only visable after I removed all the 
> modules and looked closely at the power supply. 
> 
> My unit had the old power supply and a part had melted. I was blowing fuses non stop 
and 

> couldn't figure out why. If you want to know which part the archives might mention it. 
> -could have been the transformer. Once I installed the PS2 or whatever the bigger/later 
> version everything was fine. 
> 
> TD, NYC as well!
>

Hello,
I have a G6 case with an older PS and think I blew a fuse.
Where is the fuse located?  I can't seem to find it.
Thanks,
Tim

> Hello,
> I have a G6 case with an older PS and think I blew a fuse.
> Where is the fuse located? I can't seem to find it.
> Thanks,
> Tim

www.doepfer.com > FAQ > A-100 > Which fuse is used in the A-100 frame (rear
panel):

The fuse is located at the mains inlet on the rear panel of the A-100 frame
(exception: suitcase version with mains inlet at the front). One has to
disconnect the mains cable and remove the fuse holder (e.g. with the aid of
a screw driver). The fuse holder is a small black plastic part that is
inserted into the mains inlet.

Best wishes
Dieter Doepfer

Dieter,
Many thanks!
Problem solved.
Found the fuse and changed it.
All the best,
Tim

> 
> The fuse is located at the mains inlet on the rear panel of the A-100 frame
> (exception: suitcase version with mains inlet at the front). One has to
> disconnect the mains cable and remove the fuse holder (e.g. with the aid of
> a screw driver). The fuse holder is a small black plastic part that is
> inserted into the mains inlet.
> 
> Best wishes
> Dieter Doepfer
>

Would it be safe to try 250V/400mA slow fuse for 6U basic frame with 
PSU2 in 230V/50Hz enviroment?

> Would it be safe to try 250V/400mA slow fuse for 6U basic frame with 
> PSU2 in 230V/50Hz enviroment? 

The spec says 315 mA. But I think 400mA are temporarily tolerable.

Best wishes
Dieter Doepfer