Powerproblem IO Instruments

He fellow users,
I just got the io instruments Kalyke and wanted to put it in my rack, I have the tip-top audio power supply with two ribbon cables. But when I plug in the Kalyke all the other modules don't get any power, except for the Kalyke and the other way around. So what's the problem here? I am quite new in to eurorack, so maybe this seems like a really dumb question, but I would cheer for an answer /solving

Hello @Homunkulus,

The first thing I would do is double-check that all power connections in the system are attached securely (no loose connections between each module and its power cable, each power cable's connection to the power supply ribbons, the ribbon cables' connections to the power supply, and the external power connection to the power supply) and oriented the correct way at those connections (if the ribbons don't have shrouded headers, then make sure that the red stripe is on the same side as -12V).

The second thing I would check is the power specs of the specific power supply you have (mA available on each of the +12, -12, and +5V rails) and compare that to the total load that all of the modules you have connected to it in your case. The load of all of your modules together needs to be below what your power supply can provide with some extra headroom. The amounts I hear people mention most often for this excess headroom is 20 - 30% of your power supply's maximum output. For example, if your power supply can provide a maximum of 1000 mA on each of the three power rails (1000mA @ +12V/1000 mA @ -12V/1000mA @ +5V) then you should only connect modules that need 700 - 800 mA total on each of those rails. To my understanding, this is because many modules draw more mA when first powered on than what they need to function after being powered on (which is likely what the specs provided for most modules are). Also, if your power supply relies on using an external power brick, make sure it has the appropriate wattage/voltage/amperage specs for the power supply. If the power supply accepts a range of voltages, you can try a power brick with a lower voltage within that range to get a higher amperage output (but the wattage must remain the same) Amps x Volts = Watts. It can also be useful to know if the power supply you are using splits up its power output in any way. For example, if there are two headers for ribbon cables on your supply, it is possible that the power supply's total output is divided between those two headers, so you may need to redistribute which modules are connected to each of the ribbons for a more even distribution of power draw. All of these specs should be available in the manual for your power supply.

I hope some of that helps!
Chace

Thanks to your help I found this in the manual:
Zeus Series: microZEUS with Flying Bus Boards
Using 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 o, 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.

It's exactly the fifth module 🤣 and the rack would need 250mA on the - 12V rail. I hope this will do trick. If not I might ask again 🐒

Still the same problem, but when I remove the jumper and turn it on all lights turn on +12,-12,+5, as soon as I plug in the Kalyke, the light for +12v doesn't turn on and the Kalyke gets power but the others don't. I just don't get it... So I am trying all combinations that left now, but I am getting nowhere... I also double checked every connection, switched positions of the modules on the ribbon cables, divided them between them... Nothing.

This is actually the third time I am editing this post, I've now searched all of the internets and found out that the the power provided by the yZeus is only half of what it says, so I will need that booster adapter to get the power I need. The information was really hidden in the reviews for the booster adapter...
Now I just have to wait like 3 to 4 weeks till my favorite vendor has it back in store... But still this seems to be the problem, the person who wrote the review described exactly the same problem.

But still I am glad you helped me out here and provided me with your knowledge.
Thank you

So I tried everything possible now, and it still doesn't work. I will now buy one of those small 4ms cases, maybe it will work when I outsource the Kalyke... Wish me luck :)

Darn, I'm bummed to hear that it still didn't work out =( Hopefully you'll have better luck with it on a different power supply!

Was totally worth it, the Kalyke works now with a 34hp 4ms case. And I now have additional space in my tip top rack, which I haven't thought of till now 😂 good for my GAS🐒