SD-1 Ensoniq Battery low message test

[roughshawd]

In my synth theres a program that reads the voltage in the battery and posts a value. I read about this type of circuit in high school, it just identifys a condition and then translates it into a value that that is posted by LED display or guage. This allows the equipment to warn the user that their battery is about to fail. When the battery fails and is replaced, the equipment is supposed to magically jump back to life and work...

The problem is that this equipment has a fail safe built into it that causes the little code to fail after you put a battery in it. This requires the owner to send the device back to the man and get him to reinstall the system the battery and what ever costing the owner multiple cases of tremons and a bundle of monies!

I did a lot of research on this thing. There are procedures that you have to follow when you perform the battery swap, or the system doesn't detect the new one. Now if you replace the battery without diconnecting any of the accesories...ie. the keys, the led panel, the mod pots, then the system doesn't know anything was done when you changed the battery, and it just reposts the OK values.

I did it once. It worked. But the board got hot and I didn't want to do it again. Besides all that high school BS could have been just that B*** S ***, but this last time, the main board failed(or the program isn't getting the right signal) of the new battery was made by someone who had the welder too high, or the power glitch problem happened... an all these cases, I am stuck with a "one shot Joe" synth that won't store my songs and programs anymore. Any body that can help me should, I'm sure there are a lot of problems like this out there, that should be hacked!

 

[roughshawd]

Wanted to let you guys keep up with my drill down on the greatest music synth biggest problem sortee.
I am following the repair manual and the PS is where it all starts. I am not(by a long shot I might pass the drinking fountain on the way in)a professional electronics ingenor or a novice by any means so, I could call my self an "enthusiast" and my meager attempts at repairs are mostly hit and miss....
I want you to know the first lesson in electronics should be "Its like trying to get my d#$@ in to a pinhole..."
That is most test points today are covered with either rubber or hard plastic insulation that requires an 'exacto' knife to cut away so you can get your leads on them.

After probing, twisting lightly pushing, I discovered that you can usually (using a hookscribe is best on this machines "high tension" connections) pull the terminal connector partially off of the connection to reveal a small area that you can get your probe in.
And deep in my imaginations somewhere......-
2b to 1A or 1B and all the other tests proved to be good at the mains...

personal note - never imagine that there is probably a gray wire in a connector.

 

[roughshawd]

Will try that. hope the best practices are still working afterwards.
The PS is looking ok on my synth after a few meterings. May be bad board contacts where the battery connects, or the OS has reached its limit...(I already ordered the next upgrade one and am patiently waiting for snail mail.

 

[Harald Kapp]

pull the terminal connector partially off of the connection

This may work, but is risky: If the connector isn't properly seated, there's no guarantee the connections are good and stable. On the mains side this may lead to sparking and unpleasant side effects.

 

[Martaine2005]

"Its like trying to get my d#$@ in to a pinhole..."

Some of us ‘unfortunates’ don’t have that problem!
But we do have “a fish slapping around in a bucket”.
Just my two cents!

Martin

 

[roughshawd]

Update PS looks OK
Ensoniq Power Supply Test

TEST ID TERMINALS CONNECTOR BAD GOOD
+ -
Digital Supply 1 3 J1 18.6vACrms
Analog Supply 4 6 J1 28.6vACrms
Display Filiment 7 9 J1 9.9vACrms

+5 Display 11 10 J2 4.86vDC+
+5 Digital 13 12 J2 5vDC+
VRES 14 12 J2 4.71vDC+
+12 Analog 15 18 J2 12.04vDC+
+VU 16 10 J2 10.62vDC+
-12 Analog 17 18 J2 12.04vDC-
J3 and J4 connectors are Serial(l to r)
+5 Display 20 19 J3 4.86vDC+
Vbb 21 19 J3 49.6vDC+
+12 Analog 22 19 J3 12vDC+
Display Offset 23 19 J3 10.71vDC+
Filament 23 24 J3 9.91vACrms

SD-1/VFXsd Only
+5 Display 25 26 J4 4.86vDC+
+12 Analog 28 27 J4 12.04vDC+

The differences in AC and DC goofed me up a couple times but after a few tests they are all there and line voltages too!