[sdiy] CZ-1000 update and memory mod help
Joe Frey
frey at radioles.com
Tue Mar 10 05:31:28 CET 2020
Hello all, To those that answered my original post asking for guidance I
found the problem. The output relay had gone bad and needed to be replaced.
So, after getting the synth to sound good again I decided to make an
improvement and add ram power management so my custom patches wouldn't
disappear when I put the synth in it's case for half a year. It turns
out there's a chap that made a mod that I found out about that people
say works. I contacted him and though he no longer provides the kit he
did supply the info to make that mod.
https://www.artefacts.nl/bitsandpieces.html
He also gave this advice, "_Before you start modifying the CZ you should
check if you can change the standby voltage as described in the
installation manual_. You should also check the RAM chips get a voltage
between 4.8Volt and 5.2Volt when the unit is switched on. If you can not
get these voltages within range the kit will not work."
Of course being me, I ignored the first line of the instruction and made
and installed the mod. DOH! Now, everything is cozy and in place but I
can't use the trimmer to get the standby voltage down to 3.2V. I can get
it to 3.7V. I am wondering if I put a diode in the end of the VBR
regulator circuit to use the diode drop and try and get from 3.7 to 3.2V?
The schematic is found here.
https://www.synthxl.com/wp-content/uploads/2018/01/Casio-CZ1000-schematics.pdf
And the VBR power supply is at page 4, grid 4F. And, the ribbon cable
pin I am measuring voltage at is pin 9.
Any advice is appreciated. JoeF.
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