I’m hoping for some help diagnosing a problem with my uConsole.
Setup:
uConsole with a HackerGadgets expansion/carrier board
CM4, 8GB RAM, eMMC variant (no NVMe)
Purchased from a local shop in my country, not directly from HackerGadgets
What happened:
While reassembling the device, I accidentally connected the ribbon cable to the HackerGadgets board with the 5V mark on the wrong side — and I powered the device on in this state before noticing the mistake. I’ve since disconnected power.
Current symptom:
On power-on, the screen flickers briefly, then nothing happens — no further activity, no boot. The HackerGadgets board has a red LED lit, and the uConsole motherboard has a green LED lit.
Images tried so far (flashed via the HackerGadgets expansion board):
Rex’s Debian Trixie image
uConsole_CM4_v3.1_64bit.img.bz2
Both were flashed to the eMMC through the HackerGadgets board, and both produce the same result: screen flickers on boot, then stays blank/unresponsive.
Questions:
Has anyone else recovered from a reversed 5V ribbon cable incident on the HackerGadgets board? What did you check, and what was the outcome?
Is there a way to test with a multimeter whether the board’s regulator/fuse survived, before I power it on again?
Does “screen flickers then nothing” + red/green LEDs point more toward a hardware issue or a software/image issue? Any known working image/kernel combo for CWU50 + eMMC CM4 I should try instead?
Any input — even “same thing happened to me, here’s what I did” — would be hugely appreciated. Will update this thread with what I find.
Only the earlier version of the ribbon cable has the issue when installed in reverse. Take a photo of the ribbon cable, and I will tell you which version it is.
If it’s an old version of the ribbon cable, it will recover when you remove the cable or install it the right way. Unless you charged the uConsole while the cable was installed the wrong way, one of the components on the mainboard will be damaged.
Please connect to the HDMI display to see what’s happening. Your symptom is more like the CM4 can’t load the OS than a hardware issue.
Unfortunately, I did try charging it — I’m not 100% certain, but there’s a real possibility that I did. I have tried connecting an external HDMI display, but only while using Rex’s image, and the screen stayed black.
Which ribbon cable did you install in reverse: the one connected to the RJ45 Ethernet and USB 3.0 expansion board, or the one connected to the battery board? You will only have trouble if it is the one connected to the RJ45 Ethernet and USB 3.0 expansion board.
If so, check the component the arrow points to in the following picture to see whether it is damaged.
The cable I reversed was the one connecting the battery board to the expansion board. At the time, the ribbon cable to the RJ45/USB3 board was also connected — that cable has no 5V marking on it — but I removed it during diagnostics.
