FAQ: My Omega2/2+/2S/2S+ won't boot! The serial console shows a logo and says there's 64 kB of DRAM
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The Symptoms
- When powered, the Omega2 device does not boot
- The power LED doesn't light up
- The serial console outputs this and only this:
The Root Cause
The 64 kB DRAM in the serial output is the key here. It indicates a hardware issue: the RAM is no longer connected to the MT76 SoC.
The 64kB in the screenshot is a small cache of DRAM that's internal to the SoC.What can cause this issue
This issue can be caused by a few things:
- Factory defect - possible but very unlikely since every module is extensively tested during manufacturing
- Damaged in transport - possible but not likely
- Damaged during assembly - most common for surface mount modules
Questions to ask to narrow down the issue:
- Did the module ever work before?
- If not, then it's likely a factory defect
- If it did, then it was somehow damaged
- For surface mount modules:
- Was it hand-soldered to your circuit board or was a reflow oven used? If it was a reflow oven, was the reflow profile from the Omega2S datasheet followed?
- If a hotter reflow profile was used, then it's possible the higher heat desoldered some contacts on the SoC or RAM chip
- Was the middle ground pad on the bottom of the module soldered?
- We recommend against soldering the middle ground pad. See the Omega2S datasheet for the recommended reflow profile.
- Was it hand-soldered to your circuit board or was a reflow oven used? If it was a reflow oven, was the reflow profile from the Omega2S datasheet followed?
Relevant Forum Posts
https://community.onion.io/topic/1135/omega2-not-starting-up
https://community.onion.io/topic/3969/omega2-gone-non-responsive
- When powered, the Omega2 device does not boot
