ER-102 dead

I bought a used ER-101 & ER-102 combo, after looking around for long. Got the modules this week but when I plugged them in, the ER-102 does not light up—regardless of whether it is connected or not to the ER-101. What am I doing wrong?

  1. I plugged everything correctly as in the manual (I am not a rookie, I have three different cases, totaling 1,008HP).
  2. I tried with a different case.
  3. Stopped trying because if ER-102 is defective, I don’t want to burn the ER-101.
  4. Any other solution than sending it to Brian in Japan for servicing?

I’m a sad panda :panda_face:, having waited for this for so long…

It should at least light up even when not connected to the ER-101.

  • Perhaps the PCB sandwich has separated? Make sure the main PCB (the one with the power connector on it) is properly mating with the UI PCB.
  • Check the ribbon cable that you are using to power the ER-102.
  • If you have a voltage meter, use it to measure the test points on that back that are labeled with a voltage value (i.e. +12V, +5V, +3.3V) and make sure you get proper values.
  • Finally, I would consider that the CPU on your ER-102 has somehow been bricked.

This kind of confidence could potentially hinder the debugging process. Even I will occasionally plug things in backwards.

1 Like

Thank you @odevices!

  1. The two PCBs are well joined.
  2. I jad tried with a few different ribbon cables.
  3. I get proper values except for +3.3V which shows 350mV.

Still dead. :cry:

It’s not confidence or arrogance… Sorry if it came across like this—just wanted to avoid the “have you plugged it correctly” answer first. Also, frying a Doepfer Wasp filter module was a cheap lesson to check the red stripe if in doubt. But you’re right, It could happen again.

Since both my case and the modules have shrouded headers, I assume one of this could be the cause:

  1. A static discharge or something when I plugged it in (case was powered, but I never encountered any problems before).
  2. Reversed 101-102 connection (although I checked the ER-102 manual because the PCB markings were not clear).
  3. Other thing.

Thanks again, Brian! Please let me know if anything can be done.

You plugged in the ER-102 while your case was powered up?

Yes. And case has shrouded headers, so it was impossible to plug it wrong (that’s why I am thinking of a static discharge or another electrical bad juju).

Do not do this.

Eurorack power connectors are not designed for hot plugging because GND is not guaranteed to make first contact as you plug it in. You probably damaged the CPU on the ER-102 by making a connection with the live 12V rail before GND was connected. This also matches with your observation that you no longer have a proper reading on the 3.3V test point.

Expensive lesson learned. :frowning:

What are the options for bringing it back to life? Is this someone with a good soldering hand can fix locally, or I should send it to you for servicing (that would be my first option, but I know how busy you are, and fixing stuff broken by dumb users is definitely not an exciting pastime)?

You are of course welcome to send it to me for repair. Repairs are an unavoidable part of doing business in this area. :wink:

The repair requires hot air rework on a large MCU with hundreds of pins and then the replaced MCU needs to be reflashed with a custom bootloader using a standard but pretty specific JTAG connector and pretty specific host PC software. You can try showing it to a local technician but unless they are familiar with that exact MCU, it is unlikely they could complete the entire repair. Not to mention there could be collateral damage on the board besides the MCU.

If the MCU is the only thing that needs replacing then I estimate about JPY6000 for labor/parts and JPY3000 for return shipping via EMS. If EMS is not available to your country due to COVID-19 then we might need to use a courier and return shipping will be a LOT more (probably 5x more).

I appreciate it.
Please tell me where to ship it and how to mark the package so you don’t have to pay any custom taxes etc.:slight_smile:! EMS is fine, btw.

Maybe. What country are you located in?


EMS from Japan to Romania is currently suspended, unfortunately.

Well, the alternative is looking at a beautiful dead module in my rack.
I’ll send it to you and we’ll see about return options when it’s fixed. If EMS works then fine, if not we’ll see another company (not DHL—I had to pay customs fee for a module that I sent for repair, despite having the paperwork to prove it was shipped for repair). I understand it may end up be more expensive that the 3000 JPY you mentioned.
Let me know where to ship it.

Ok so this thread got curious and if the same “hot plugging” is bad when using a test meter with keyed header (i.e Test 3 from Joranalogue Audio Design) to test a module’s current draw??? You see it in the “Test 3” demo videos, live hot plugging and I’m hoping there’s some sort of module protection going on when doing so? If the Test 3 does offer some sort of protection it would be easy to get confused thinking the same hot plugging is acceptable going directly into a the bus board in a modular rack.