Vintage Synth Repair

greetings 
    I am in need of the factory obx diagnostic ROM
or the file so I can burn one
any leads would be most appriciated 
Kevin S

It would be nice to have if anyone can has a ROM image file for it but I've fixed a few OB-Xs and never found I needed it. Usually you can just use a meter and scope to find faults. What's the problem with yours? Doug synthparts.com

--- In vintagesynthrepair@yahoogroups.com, cordanova@... wrote:

>
> greetings 
>     I am in need of the factory obx diagnostic ROM
> or the file so I can burn one
> any leads would be most appriciated 
> Kevin S
>

greetings Doug:
   thanks for the reply. I'll try to make this brief.

1) no scanning of pot, switches, LEDs or D/A converter

2) supplies good, no ripple

3) data and address buss lines all active, look clean on 'scope

4) IC 108  (74LS42) pin 1  (ROM 0*) active.

5) All other fan out "glue" logic: no activity.

I would guess that the system fetches it initial instructions from ROM 0
Bad ROM????
What do you say?
MY ROM burner/reader can't read 2708s only 2716s and on up.

when I get this beast running I will need key tops. Do you sell those?

cheers
Kevin Siegenthaler




________________________________
From: synthparts <synthparts@...>
To: vintagesynthrepair@yahoogroups.com
Sent: Monday, September 5, 2011 4:04 AM
Subject: [vintagesynthrepair] Re: Oberheim OB-X diagnostic ROM


  
It would be nice to have if anyone can has a ROM image file for it but I've fixed a few OB-Xs and never found I needed it. Usually you can just use a meter and scope to find faults. What's the problem with yours? Doug synthparts.com

--- In vintagesynthrepair@yahoogroups.com, cordanova@... wrote:

>
> greetings 
>     I am in need of the factory obx diagnostic ROM
> or the file so I can burn one
> any leads would be most appriciated 
> Kevin S
>

I would recommend what a friend and I did and replace the old triple supply 2708s with a 2732. This is what we did -

http://www.retrosynth.com/docs/obx/rom_hack/

ROM image for the 2732 is there.

Doug 
synthparts.com

--- In vintagesynthrepair@yahoogroups.com, kevin siegenthaler <cordanova@...> wrote:

>
> greetings Doug:
> Â  Â thanks for the reply. I'll try to make this brief.
> 
> 1) no scanning of pot, switches, LEDs or D/A converter
> 
> 2) supplies good, no ripple
> 
> 3) data and address buss lines all active, look clean on 'scope
> 
> 4) IC 108 Â (74LS42) pin 1 Â (ROM 0*) active.
> 
> 5) All other fan out "glue" logic: no activity.
> 
> I would guess that the system fetches it initial instructions from ROM 0
> Bad ROM????
> What do you say?
> MY ROM burner/reader can't read 2708s only 2716s and on up.
> 
> when I get this beast running I will need key tops. Do you sell those?
> 
> cheers
> Kevin Siegenthaler
> 
> 
> 
> 
> ________________________________
> From: synthparts <synthparts@...>
> To: vintagesynthrepair@yahoogroups.com
> Sent: Monday, September 5, 2011 4:04 AM
> Subject: [vintagesynthrepair] Re: Oberheim OB-X diagnostic ROM
> 
> 
> Â  
> It would be nice to have if anyone can has a ROM image file for it but I've fixed a few OB-Xs and never found I needed it. Usually you can just use a meter and scope to find faults. What's the problem with yours? Doug synthparts.com
> 
> --- In vintagesynthrepair@yahoogroups.com, cordanova@ wrote:
> >
> > greetings 
> >     I am in need of the factory obx diagnostic ROM
> > or the file so I can burn one
> > any leads would be most appriciated 
> > Kevin S
> >
>