Vintage Synth Repair

hi there!

i´ve got a rev3 in great cosmetical shape. i keep it in a studio and
i´ve never taken it on a gig... one day it broke down and now it only 
makes funny noises when i play. just noise and weird modulated stuff!
has anyone out there got an idea of what can be going on!!?!? is
there anythig i can try before i get i serviced!?!?!??? also when
it´s functioning "normaly" the led flashes a little bit when i turn
the knobs and the filtersweeps sounds a bit stepped when i use the
button!!! is that normal?!??

cheers! and thanks!

Daniel

One usual problem of prophets is the powersupply. Is that allright?

reg,
Eric.


--- In vintagesynthrepair@yahoogroups.com, "daniel_muschinsky" 
<daniel@s...> wrote:
> 
> hi there!
> 
> i´ve got a rev3 in great cosmetical shape. i keep it in a studio and
> i´ve never taken it on a gig... one day it broke down and now it 
only 
> makes funny noises when i play. just noise and weird modulated 
stuff!

> has anyone out there got an idea of what can be going on!!?!? is
> there anythig i can try before i get i serviced!?!?!??? also when
> it´s functioning "normaly" the led flashes a little bit when i turn
> the knobs and the filtersweeps sounds a bit stepped when i use the
> button!!! is that normal?!??
> 
> cheers! and thanks!
> 
> Daniel

The flashing led's is not unusual with P5's - often due to power supply
problems. I have a P5 that shows this to varying and unpredictable degrees.
There is an "official" power supply kludge but it might be a better idea to
retrofit a better supply. A good synth tech shouldn’t have much trouble with
this.

The sound problems could be caused by a power supply or you may have lost
the preset memories. Can you set up a good sound manually? 

Another problem I have seen is pots get "latched" in an intermediate state
with the scanning hardware. Try cycling all the rotary controls back and
forth a few times then program a sound to see if you get lucky.

mw

-----Original Message-----
From: desteric [mailto:desteric@...] 
Sent: Tuesday, July 20, 2004 11:45 AM
To: vintagesynthrepair@yahoogroups.com
Subject: [vintagesynthrepair] Re: prophet 5 not working!!!

One usual problem of prophets is the powersupply. Is that allright?

reg,
Eric.


--- In vintagesynthrepair@yahoogroups.com, "daniel_muschinsky" 
<daniel@s...> wrote:
> 
> hi there!
> 
> i´ve got a rev3 in great cosmetical shape. i keep it in a studio and
> i´ve never taken it on a gig... one day it broke down and now it 
only 
> makes funny noises when i play. just noise and weird modulated 
stuff!
> has anyone out there got an idea of what can be going on!!?!? is
> there anythig i can try before i get i serviced!?!?!??? also when
> it´s functioning "normaly" the led flashes a little bit when i turn
> the knobs and the filtersweeps sounds a bit stepped when i use the
> button!!! is that normal?!??
> 
> cheers! and thanks!
> 
> Daniel




 
Yahoo! Groups Links

--- In vintagesynthrepair@yahoogroups.com, "daniel_muschinsky" 
<daniel@s...> wrote:
> 
> hi there!
> 
> i´ve got a rev3 in great cosmetical shape. i keep it in a studio and
> i´ve never taken it on a gig... one day it broke down and now it 
only 
> makes funny noises when i play. just noise and weird modulated 
stuff!
> has anyone out there got an idea of what can be going on!!?!? is
> there anythig i can try before i get i serviced!?!?!??? also when
> it´s functioning "normaly" the led flashes a little bit when i turn
> the knobs and the filtersweeps sounds a bit stepped when i use the
> button!!! is that normal?!??
> 
> cheers! and thanks!
> 
> Daniel

I think LED's flash due to the main Z80 proceesor not having enough 
grunt.

Filter sweeps sound stepped in the Prophet due to their settings 
being held in digital memory,it's one of my main complaints with the 
Prophet.

Sounds very familiar to me. Sounds to me like the back-up memory battery
has gone south. Backup battery is soldered to the main cpu PCB. Should
measure at least 2.8 volts dc. When the battery goes south, miscellaneous
data appears in the ram such that all your patches are playing with the
control
knobs in various bizarre settings.
Try this-go into the manual mode-then set-up a patch from scratch. if a
sound appears then i'll betcha your battery is history. Note that merely
replacing the battery will not restore your sounds. You will have to as well
reprogram the beast. Good luck and au reservoir. Russ

>> 
>> hi there!
>> 
>> i´ve got a rev3 in great cosmetical shape. i keep it in a studio and
>> i´ve never taken it on a gig... one day it broke down and now it
> only 
>> makes funny noises when i play. just noise and weird modulated
> stuff!
>> has anyone out there got an idea of what can be going on!!?!? is
>> there anythig i can try before i get i serviced!?!?!??? also when
>> it´s functioning "normaly" the led flashes a little bit when i turn
>> the knobs and the filtersweeps sounds a bit stepped when i use the
>> button!!! is that normal?!??
>> 
>> cheers! and thanks!
>> 
>> Daniel
> 
> I think LED's flash due to the main Z80 proceesor not having enough
> grunt.
> 
> Filter sweeps sound stepped in the Prophet due to their settings
> being held in digital memory,it's one of my main complaints with the
> Prophet.
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
> 
>

Oh and one more thing about your LED's blinnking when you play keys or
change patches or go into edit mode, every prophet 5 I've fixed in the last
18.97 years does this even when they are behaving properly does this.
So ass our great prophet Bud Dolan says"dont think twice, it's allright"
Regardio, Russ

>> 
>> hi there!
>> 
>> i´ve got a rev3 in great cosmetical shape. i keep it in a studio and
>> i´ve never taken it on a gig... one day it broke down and now it
> only 
>> makes funny noises when i play. just noise and weird modulated
> stuff!
>> has anyone out there got an idea of what can be going on!!?!? is
>> there anythig i can try before i get i serviced!?!?!??? also when
>> it´s functioning "normaly" the led flashes a little bit when i turn
>> the knobs and the filtersweeps sounds a bit stepped when i use the
>> button!!! is that normal?!??
>> 
>> cheers! and thanks!
>> 
>> Daniel
> 
> I think LED's flash due to the main Z80 proceesor not having enough
> grunt.
> 
> Filter sweeps sound stepped in the Prophet due to their settings
> being held in digital memory,it's one of my main complaints with the
> Prophet.
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
> 
>