<![CDATA[Hardware issues]]>Sharing issues we've had with the hardware (problems that turned out to be due to the physical module).

  • 4-Relay modules (U097). Several modules in different applications had relays that "stuck" off. The LED came on, but the relay did not close. Desoldering them from the board confirmed they were not functional, and a teardown confirmed that they could work. Our solution was to replace the relays with TE equivalents (T77S1D3-05). The most recent relay modules haven't exhibited this problem so far.
  • DAC2 modules (U012-B). Two of three modules are dead. Both seem to be having problems with the boost converter (provides 12V for the DAC 10V range). Output of one boost is ~5V, no switching at the SW pin. Other boost gets really warm. Analysis ongoing to what and why they failed. Anyone have insight here?

Anyone have other issues (and hopefully fixes)?

]]>https://community.m5stack.com/topic/7578/hardware-issuesRSS for NodeWed, 29 Apr 2026 04:14:11 GMTTue, 27 May 2025 22:50:58 GMT60<![CDATA[Reply to Hardware issues on Wed, 11 Jun 2025 15:08:23 GMT]]>Update on DAC module: found probable root cause from within my system setup.

Failure point on the module is the +5V input - only a few ohms vs GND. I found the +5Vdc supply transient of -4V relative to GND for 200µs. Most ICs don't do well with anything below -0.3V relative to GND.

(the transient is caused by design depending on a great deal of Grove wiring as a GND path, combined with relatively high voltage/current on other rails in the system. One solution is redesign for low-ohm, low impedance GNDs)

]]>https://community.m5stack.com/post/29221https://community.m5stack.com/post/29221Wed, 11 Jun 2025 15:08:23 GMT