Trouble with a small MI system

Hi everyone! Please help a modular noob out. As my first foray into modular, I decided to build a tiny FX skiff to go with my Dreadbox Erebus. So I ordered Mutable Clouds, Peaks & Shades, and an Erica Synths Pico Case (/w power supply).
Now, the problem is as follows:

  1. Clouds doesn’t work at all - no LEDs flashing, no sound coming out, nothing;
  2. Peaks doesn’t work either. However, one of its LEDs flashes for half a second when I turn on the power, then everything goes dead;
  3. Shades seems to work fine, but only if it’s the only module connected. As soon as I connect Peaks or Clouds, Shades goes dead, too.

I’ve made sure that the polarity is correct, and there was no hiss/kaboom/smoke, so I hope the modules are ok. I suspect that the power supply in the Pico Case doesn’t output enough power (although it should be plenty enough according to the specs). But I’m not great with electronics - I’m just a musician who wanted to explore a different instrument.

So, what should I do before I return it to the store? What exactly should I check regarding the power supply? And is there a way to determine whether the modules are fine, seeing that I’m the only synth guy in my area, so I can’t try them with someone else’s system? Thanks in advance, and I apologize if my questions are stupid - I’ve just never dealt with this stuff before.

I’m afraid there’s not much you can test by yourself - maybe it’s something wrong with the PSU, maybe, but more unlikely both Peaks and Clouds are dead (but occurrences of DOA modules are very rare, so it’s very unlikely to get two of them together).

Where did you buy them? Maybe as a first step you can return them to the shop and they can test them for you.

The specs of that power supply should be more than enough for all of those modules at once. It sounds like something might be wrong with the case, I would try to exchange it for a new one, a different model perhaps. I assume you double checked the polarity of the cable on both the module and case side? They should arrive correct on the module, but just to be sure.

I bought them from Musicstore.de. Problem is, I’m in Russia, so the whole procedure will probably take a lot of time due to international shipping. But yes, looks like I’ll have to do that, unless I find someone willing to test them for me within my country.

I was just worried that I’d fried the modules, but there’s no visible damage, and the red stripe definitely went to -12V on both ends. So I hope it’s just the PSU.

Thank you for your answers!