I built another Case :
ModularGrid Rack

and wanted to use the uZeus with a 3000 mA PSU Adapter. When i turned it on the -12v led didnt light up, but the other ones did. Some modules powered on, too but I quickly turned the PSU down because I feared of destroying anthing.
I also found something in the manual of the uZeus regarding the -12v rail:

"The –12V rail uses a switching regulator. This switching regulator needs to
have a minimum load of 100mA (out of 500mA) at any given time. The
uZeus has a factory setting to self consume this current. If your uZeus is
powering more than four (4) analog modules you can then disable this
setting if desired to make this 100mA available for use by your modules.
With the uZeus powered off, look for header J7 (located below the blue
resistor) and remove the jumper. Re-insert the jumper such that it comes in
contact with only one pin. Once reinstalled in the system, the uZeus will
provide the full 500mA of –12V power for your modules"

Do I just need to remove the jumper? If not, what are the best steps to debugging?

Thanks in advance!


Yes. Even with the jumper removed though, it looks like you are probably pushing the -12V rail close to it's limits. So definitely remove the jumper, but pay close attention to the lights on the UZeus when it powers on. If they blink when you power on then that means you're probably pushing it too hard. All the lights should turn on immediately. Also feel the faceplate of the UZeus after you've had it on for awhile. If it feels like you're going to burn your finger then again, you're probably pushing it too hard.

You need to get in the habit of looking at the power consumption numbers listed in Modular Grid to give you an idea of how much power your rack is using. Yeah it's just a rough estimate, but in this instance it's 478 mA on the -12V rail, that tells you right away that you definitely need to remove the jumper. Given all the space you have left in the rack, you're definitely going to need more power for that rail when you add more modules. A 4MS Row Power module might be a better idea for the remainder of the rack (it provides more power on the -12V rail).


Thanks for your reply! I removed the jumper and one module with 50ma on the -12 bus and now all 3 leds are on. I will monitor the temperature while playing a few minutes... But Are there any better solutions on upgrading mA on the -12v bus than just adding a new set of PSU? I once saw a brand which allows daisy chaining two psu modules. I think it was by 4ms... Its a bit annoying because I thought buying the Boost PSU by Tip top audio would be enough to power the whole row (which is indead very long because it sits on top of 2 other racks)


Yeah I mean I guess it depends on what modules you have, but IMO powering 185 HP with one uZeus isn't very realistic. I'm not an expert on power and I'm sure others would have recommended a more robust power solution from the beginning, but given that you already have the uZeus, I think a 4MS Row Power 35 would work fine for the remainder of the rack. And yes they can be daisy chained to run off the same power brick, but not to my knowledge with the uZeus. You could go with a second uZeus instead I guess and save money, but my thinking is it would be better to give yourself some elbow room in terms of the -12V rail so that you don't have to worry about running out of power.

Not having everything running off the same power supply can be useful sometimes, for example, if you have a module that's sensitive to picking up interference from other modules, then having the ability to separate them and run them off of different supplies can be handy. I have a pretty large system which includes several uZeus modules, 4MS Pods, and a Row Power 45 in addition to some Dopefer cases, and it's worked out ok for me.