[sdiy] May Be Somewhat OT: Repairing a DOD 1222 XL Mixer

[Scott Gravenhorst]

cheater cheater <cheater00 at gmail.com> wrote:
>The circular hole: With a 220V AC I would assume it's a fuse hole. You
>can have a fuse that screws into a socket. Lots of equipment has
>those.
>http://www.pridediyjunk.com/catalog/images/fuse%20socket.jpg
>The cap in those (marked with white writings) screws off and opens to
>show a socket. The fuse is held by a mechanism similar to flashlights
>etc. Thje thing's diameter is less than under a centimeter, maybe 7mm,
>but check a datasheet - the last time I've seen those was several
>years ago.
>
>Putting the fuse right next to the power socket is very classical as well.
>
>1.8A is still a lot of current and I wouldn't be supprised if this
>thing were fused.
>
>Maybe the wallwart socket was connected through the fuse box in the first place?

If there's a fuse anywhere in it, I don't see it.  The hole is smaller than a pencil.  there
could be a fuse inside the wallwart unit, but it's not replacable from the outside like the
image to which you refer.

BTW, the power supply is repaired, the unit powers up without exploding.  Power light comes
on and phantom power goes on and off with the phantom switch.  Next will be to test it with a
real signal and some headphones - but that's for tomorrow after I've finished putting all of
the screws back in it.  There has to be 40 or 50 of them.

>HTH
>D.
>
>On Wed, Feb 11, 2009 at 3:41 PM, Scott Gravenhorst <music.maker at gte.net> wrote:
>> Hello all,
>>
>> I'm not sure how off topic this is, it has to do with the mixer 
>I use when recording with my synthesizers... > > Anyway, one of 
>the 4 power supply filter electrolytic caps is obviously blown, 
>so I've ordered them and they should arrive in a few days, I will 
>replace all 4. > > Does anyone have one of these mixers? > > On 
>the rear next to the rectangular hole where the power connector 
>for the wall wart is, there is a round hole - what is supposed to 
>be there? > > Also inside on the "power board" (which is a 
>combination of power supply with two 3-term regulators and also 
>has all of the 1/4 inch output jacks), there is something that 
>looks like it was unsoldered and removed - but I didn't do that, 
>it's labeled H4, has 3 holes for soldered connectors two if which 
>are shorted together and the third is by itself (so it really has 
>only two connections). The wallwart socket connects directly to 
>these pins, one side to the shorted pins, the other to the alone 
>pin - as if > there's an indicator light, but the transformer is 
>AC, so I'm assuming it's not an LED. The wallwart is 10VAC, 1.8A 
>- so it can't be a neon bulb. At first I thought it was a power 
>switch, but that can't be because if it were, it would short the 
>wallwart when closed. > > It's been broken for over a year now, 
>and I've got a bad habit of leaving things like this turned on - 
>I can't remember if it ever had a power switch. It has a power 
>LED indicator on the front panel, but I cannot find a power 
>switch (other than the phantom power switch for the microphone 
>connectors). > > It was not very expensive when I purchased it 
>and I've googled until I'm blue in the face for schematic for it. 
>It's old enough that all parts are through hole. > > Can anyone 
>help - either with a quick look on the back (don't need to open 
>it up) or perhaps someone has a schematic? > > Thanks in advance 
>for any info. > > -- ScottG > 
>________________________________________________________________________ 
>> -- Scott Gravenhorst > -- FPGA MIDI Synthesizer Information: 
>home1.gte.net/res0658s/FPGA_synth/ > -- FatMan: 
>home1.gte.net/res0658s/fatman/ > -- NonFatMan: 
>home1.gte.net/res0658s/electronics/ > -- When the going gets 
>tough, the tough use the command line. > > 
>_______________________________________________ > Synth-diy 
>mailing list > Synth-diy at dropmix.xs4all.nl > 
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy > 
>
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/FPGA_synth/
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- When the going gets tough, the tough use the command line.