Emu XL-7 & MP-7 User's Group

Hi group members please can you help me !

Upon my return from holiday I was horrified to find that my MP7 wont power
up! Ive tried numerous different power leads and nothing.......... There is
a possibility someone switched it on by accident while I was away and if so
then it could have been left on for a long time. Please can someone suggest
how I go about fixing this as I love this purple machine and need to use
it.. Does anyone know if there are any internal fuses that may have blown
or where I may be able to get a new power supply from ????

B.

Thanks for the quick response!

I have tried the hard switch and still nothing. I generally leave the hard
switch on and use the soft one, as its in a rack, however when it gets
switched off at the wall and then switched back on again it would power up
without touching the soft switch this is how I suspect it was turned on
accidentally. Ive had a quick look through the archived posts and it seems
that replacement power supplies are not available?? (please correct me if
I'm wrong) So I guess I've gotta mod an ATX PSU, before I do this though is
there any way I can tell if this problem goes beyond the PSU i.e. how do I
tell if my main board is fried or not and whether it is worth trying to fix
the psu??

Many thanks for any and all help :)





On 25 January 2012 at 03:57 Andrew <Alan_mansfield@...> wrote:

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> There is an internal fuse... someone with better knowledge of the guts
can tell you more about that.  Before you go that route, have you tried the
hard switch on the back of the unit... sometimes flipping it off with the
hard switch and letting it sit a few minutes before powering it back up can
correct this issue.  For whatever reason, on some units, if you always use
the soft switch on the face/front of the unit it will occasionally not
power up.  If it does happen to be an issue with the power supply, look
back through the archives... somebody posted awhile back how to mod a
computer's 5v supply to power a unit... also check erpelectronics.com, they
might have one.  However, unless you noticed your unit getting really hot
recently, it probably isn't the power supply... When I was going all
hardcore with mine, I used to hardly ever turn it off... it would be on for
months, and never had any issues with the power.
> To: xl7@yahoogroups.com
> From: barnabyandrews@...
> Date: Tue, 24 Jan 2012 23:44:44 +0000
> Subject: [xl7] Please HELP! My MP7 wont switch on!
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>    Hi group members please can you help me !
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>     Upon my return from holiday I was horrified to find that my MP7 wont
power up! Ive tried numerous different power leads and nothing..........
There is a possibility someone switched it on by accident while I was away
and if so then it could have been left on for a long time. Please can
someone suggest how I go about fixing this as I love this purple machine
and need to use it.. Does anyone know if there are any internal fuses that
may have blown or
>     where I may be able to get a new power supply from ????
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Do you own a voltmeter? Using one you should be able to check the supply
to figure out if that's the problem or not. You can get to the supply by
removing the 8 screws on the bottom black section of the case. I am
pretty sure the power supply has a label on it which lets you know what
voltage should be on each of its output's. If not let me know and I can
measure my supply.

 

Note that the fuse is internal to the power supply. If it is blown be
sure to take a look for sign of other problems since it's pretty
uncommon for fuses to blow for no real reason.

are these PSUs refurbable

\ufffd

are these PSUs refurbable

On Jan 25, 2012 6:03 AM, "Ryan, David" <RyanD@...> wrote:

\ufffd

Do you own a voltmeter? Using one you should be able to check the supply to figure out if that\ufffds the problem or not. You can get to the supply by removing the 8 screws on the bottom black section of the case. I am pretty sure the power supply has a label on it which lets you know what voltage should be on each of its output\ufffds. If not let me know and I can measure my supply.

\ufffd

Note that the fuse is internal to the power supply. If it is blown be sure to take a look for sign of other problems since it\ufffds pretty uncommon for fuses to blow for no real reason.

bonjour a tous

La panne est certainement la resistance qui alimente le uc3842 .

La resistance est : marron rouge jaune (120kohms) 2Watts

Elle se trouve dans l'angle interieur du dissipateur.

aller voir ici ==> http://img593.imageshack.us/img593/558/emualimdesecourmp7001.jpg

I had this happen with my P2500. I alway left the back power switch on and just toggled My E-Mu on and off via the front button. Eventually, the front button did not seem to be working well. It seemed like a faulty/dirty switch. Then I read a post about the same issue. Now I use the front button to toggle my E-Mu off first and then turn it off from the back.

Someone said something about the power supply being affected by always leaving the back switch on. I have no idea. I just know what works for me. Maybe it will help in others' situations.

Steve

--- In xl7@yahoogroups.com, Andrew <Alan_mansfield@...> wrote:

[snip]

> have you tried the hard switch on the back of the unit... sometimes flipping it off with the hard switch and letting it sit a few minutes before powering it back up can correct this issue.  For whatever reason, on some units, if you always use the soft switch on the face/front of the unit it will occasionally not power up.

PS: If the main power goes out and your E-Mu's back switch is on, when the main power goes back on, the E-Mu [CC and P2500, that is] will boot. (And your digital clocks that don't have battery backup/power will probably have the wrong time!)
Steve

2012/1/25 steve_the_composer <smw-mail@...>:
> I had this happen with my P2500. I alway left the back power switch on and just toggled My E-Mu on and off via the front button. Eventually, the front button did not seem to be working well. It seemed like a faulty/dirty switch. Then I read a post about the same issue. Now I use the front button to toggle my E-Mu off first and then turn it off from the back.
>
> Someone said something about the power supply being affected by always leaving the back switch on. I have no idea. I just know what works for me. Maybe it will help in others' situations.

I have the same "faulty/dirty switch" issue. Good to know, thanks Steve!

Usually I just left the all my synths on (including MP7), and turn
on/off the power strip in my rack. That was actually my biggest
improvement in the studio - reducing the boot-up time...

Nicko - merci pour votre explication! Il peut être très utile pour
tous les abonnés de la liste.

Bruno

While it's not necessarily your issue, the xx7 power supplies have crappy electrolytics and are failure-prone.  Recapping is not that hard (getting the power supply out of its little cage is probably harder); however, I've not, up to this point, seen a funky power supply cause the machine to stop working like that--usually there are weird behaviors before complete failure.

Tom
>

What are the weird behavior symptoms?

Weird behaviors from bad power supply:

On my MP-7, everything would work okay and then all the controls would start responding freakishly slowly.  Occasionally the instrument would make odd sounds on its own.  On the Proteus modules, the LCD backlight will dim or disappear.  

Recap is fairly simple, parts inexpensive.  If a cap has leaked, check for corrosion on any of the other circuit boards.  

tom

Hey there,

Sorry to hear about that. There is an internal fuse inside the PSU. If the fuse has blown, it may be the sign of other problems in the PSU sadly.

My friend's XL7 had the same problem as yours, we checked the internal fuse, it was OK. In the end we managed to get it fixed superbly by a great PSU repair place in Wirral, UK, for under £50. Details here:

http://launch.groups.yahoo.com/group/xl7/message/22347

Matt

 

--- In xl7@yahoogroups.com, "barnabyandrews@..." <barnabyandrews@...> wrote:
>
> Hi group members please can you help me !
> 
> Upon my return from holiday I was horrified to find that my MP7 wont power
> up! Ive tried numerous different power leads and nothing.......... There is
> a possibility someone switched it on by accident while I was away and if so
> then it could have been left on for a long time. Please can someone suggest
> how I go about fixing this as I love this purple machine and need to use
> it.. Does anyone know if there are any internal fuses that may have blown
> or where I may be able to get a new power supply from ????
> 
> B.
>