Vintage Simmons Drums (UK) Users Group

So,

my SDS7 died a few weeks ago.

It has 12 modules and runs very hot. The rectifier for the +5V made a noise
and the display flickered in and out.

I´ve removed all modules and the CPU starts and run with no problem.
Reseating modules one at a time works fine but the more modules that are
connected, the more there is noise on the +5V rail ( no kidd....lol ). The
VCO´s sound garbled and the audio output has hum.

I have replaced the capacitor on the +5V rail but there is still around 1V
AC half wave noise on it. Both before the regulator and after the regulator.
This leads me to believe that I need to replace the rectifier bridge with
one that can output more current.

Does anyone have any suggestion for a suitable one ?

WT

i'm really sorry to hear this, hope help comes soon buddy!

/k



________________________________
Från: WT <waveterm@...>
Till: Simmons_Drums@yahoogroups.com
Skickat: fredag, 16 september 2011 22:52
Ämne: [Simmons Drums] SDS7 repairs



So,

my SDS7 died a few weeks ago.

It has 12 modules and runs very hot. The rectifier for the +5V made a noise
and the display flickered in and out.

I´ve removed all modules and the CPU starts and run with no problem.
Reseating modules one at a time works fine but the more modules that are
connected, the more there is noise on the +5V rail ( no kidd....lol ). The
VCO´s sound garbled and the audio output has hum.

I have replaced the capacitor on the +5V rail but there is still around 1V
AC half wave noise on it. Both before the regulator and after the regulator.
This leads me to believe that I need to replace the rectifier bridge with
one that can output more current.

Does anyone have any suggestion for a suitable one ?

WT




[Non-text portions of this message have been removed]

you can send me a pic of it so I could look if I have one ?
Tell me via private mail.
good luck,
Patrice.



----- Mail d'origine -----
De: KW
À: Simmons Drums
Envoyé: Sat, 17 Sep 2011 07:26:24 +0200 (CEST)
Objet: SV: [Simmons Drums] SDS7 repairs


























i'm really sorry to hear this, hope help comes soon buddy!



/k



________________________________

Från: WT <waveterm@...>

Till: Simmons_Drums@yahoogroups.com

Skickat: fredag, 16 september 2011 22:52

Ämne: [Simmons Drums] SDS7 repairs





So,



my SDS7 died a few weeks ago.



It has 12 modules and runs very hot. The rectifier for the +5V made a noise

and the display flickered in and out.



I´ve removed all modules and the CPU starts and run with no problem.

Reseating modules one at a time works fine but the more modules that are

connected, the more there is noise on the +5V rail ( no kidd....lol ). The

VCO´s sound garbled and the audio output has hum.



I have replaced the capacitor on the +5V rail but there is still around 1V

AC half wave noise on it. Both before the regulator and after the regulator.

This leads me to believe that I need to replace the rectifier bridge with

one that can output more current.



Does anyone have any suggestion for a suitable one ?



WT



[Non-text portions of this message have been removed]

























[Non-text portions of this message have been removed]

> I have replaced the capacitor on the +5V rail but there is still around 1V
> AC half wave noise on it. Both before the regulator and after the regulator.
> This leads me to believe that I need to replace the rectifier bridge with
> one that can output more current.

The diode bridge has failed, with one diode going short-circuit. This is surprisingly common - far more than failed capacitors which never go unless they get cooked off by a shorted rectifier!

Any very large diode bridge will do. I would tend to make one up out of discrete 10A 400V diodes, but only because I've got hundreds of them to get through ;-)

Gordon MM0YEQ

Yep,

rectifier is broken.

Should I replace it with an identical or find one that can handle more current ?

Any tips on a suitable one ?

WT

----- Original Message -----
From: Michael Buchner
To: waveterm@...
Sent: Saturday, September 17, 2011 2:33 AM
Subject: Re: SDS7 repairs


It looks like one of the rectifyer diodes is down. You can check this with a multimeter, but the rectifyer is so cheap that it is no thing to replace it.
The problem is happening only under load (massive power consumption). So, my bet is: Not the cap but the rectifyer (semi-conductor).
Best
Michael

[Non-text portions of this message have been removed]

Thanks mate !

WT

----- Original Message -----
From: "KW" <memtechlist@...>
To: <Simmons_Drums@yahoogroups.com>
Sent: Saturday, September 17, 2011 7:26 AM
Subject: SV: [Simmons Drums] SDS7 repairs


i'm really sorry to hear this, hope help comes soon buddy!

/k



________________________________
Från: WT <waveterm@...>
Till: Simmons_Drums@yahoogroups.com
Skickat: fredag, 16 september 2011 22:52
Ämne: [Simmons Drums] SDS7 repairs



So,

my SDS7 died a few weeks ago.

It has 12 modules and runs very hot. The rectifier for the +5V made a noise
and the display flickered in and out.

I´ve removed all modules and the CPU starts and run with no problem.
Reseating modules one at a time works fine but the more modules that are
connected, the more there is noise on the +5V rail ( no kidd....lol ). The
VCO´s sound garbled and the audio output has hum.

I have replaced the capacitor on the +5V rail but there is still around 1V
AC half wave noise on it. Both before the regulator and after the regulator.
This leads me to believe that I need to replace the rectifier bridge with
one that can output more current.

Does anyone have any suggestion for a suitable one ?

WT




[Non-text portions of this message have been removed]



------------------------------------

Yahoo! Groups Links

Installed now is an RS 261-491

http://se.rs-online.com/web/cpd/0261491/?searchTerm=261-491

WT

----- Original Message -----
From: <Jacquot.Patrice@...>
To: "Simmons Drums" <Simmons_Drums@yahoogroups.com>
Sent: Saturday, September 17, 2011 4:16 PM
Subject: Re: SV: [Simmons Drums] SDS7 repairs


you can send me a pic of it so I could look if I have one ?
Tell me via private mail.
good luck,
Patrice.



----- Mail d'origine -----
De: KW
À: Simmons Drums
Envoyé: Sat, 17 Sep 2011 07:26:24 +0200 (CEST)
Objet: SV: [Simmons Drums] SDS7 repairs


























i'm really sorry to hear this, hope help comes soon buddy!



/k



________________________________

Från: WT <waveterm@...>

Till: Simmons_Drums@yahoogroups.com

Skickat: fredag, 16 september 2011 22:52

Ämne: [Simmons Drums] SDS7 repairs





So,



my SDS7 died a few weeks ago.



It has 12 modules and runs very hot. The rectifier for the +5V made a noise

and the display flickered in and out.



I´ve removed all modules and the CPU starts and run with no problem.

Reseating modules one at a time works fine but the more modules that are

connected, the more there is noise on the +5V rail ( no kidd....lol ). The

VCO´s sound garbled and the audio output has hum.



I have replaced the capacitor on the +5V rail but there is still around 1V

AC half wave noise on it. Both before the regulator and after the regulator.

This leads me to believe that I need to replace the rectifier bridge with

one that can output more current.



Does anyone have any suggestion for a suitable one ?



WT



[Non-text portions of this message have been removed]

























[Non-text portions of this message have been removed]



------------------------------------

Yahoo! Groups Links

Yeah, I´ve seen this before in a couple of PPG Wave´s and a few other
devices.

There´s not a lot of to get in there and do such a mod. I think just
replacing it with a similar one will be a big hassle due to the
construction. Getting the card out means stripping the whole mainframe down
to its bare minimum.

WT

----- Original Message -----
From: "gordonjcp" <gordon@...>
To: <Simmons_Drums@yahoogroups.com>
Sent: Sunday, September 18, 2011 2:38 PM
Subject: [Simmons Drums] Re: SDS7 repairs


>
>> I have replaced the capacitor on the +5V rail but there is still around
>> 1V
>> AC half wave noise on it. Both before the regulator and after the
>> regulator.
>> This leads me to believe that I need to replace the rectifier bridge with
>> one that can output more current.
>
> The diode bridge has failed, with one diode going short-circuit. This is
> surprisingly common - far more than failed capacitors which never go
> unless they get cooked off by a shorted rectifier!
>
> Any very large diode bridge will do. I would tend to make one up out of
> discrete 10A 400V diodes, but only because I've got hundreds of them to
> get through ;-)
>
> Gordon MM0YEQ
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

Arschel !!!

Changed the rectifier for a bigger 4A one and it made it worse.

Now I have ripple on +15V and on -5V. Sigh.....

Will change the +5V Regulator.

WT - Not happy....

----- Original Message -----
From: "WT" <waveterm@...>
To: <Simmons_Drums@yahoogroups.com>
Sent: Sunday, September 18, 2011 2:56 PM
Subject: [Simmons Drums] Re: SDS7 repairs


> Yep,
>
> rectifier is broken.
>
> Should I replace it with an identical or find one that can handle more
> current ?
>
> Any tips on a suitable one ?
>
> WT
>
> ----- Original Message -----
> From: Michael Buchner
> To: waveterm@...
> Sent: Saturday, September 17, 2011 2:33 AM
> Subject: Re: SDS7 repairs
>
>
> It looks like one of the rectifyer diodes is down. You can check this
> with a multimeter, but the rectifyer is so cheap that it is no thing to
> replace it.
> The problem is happening only under load (massive power consumption). So,
> my bet is: Not the cap but the rectifyer (semi-conductor).
> Best
> Michael
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>