Picked up an Ender 3 off eBay after Christmas in an "brand new open box" state. Should be covered under warranty, and I shelled out an extra $6 for the Allstate Protection Plan, so I should have coverage even if the reseller drops off.
During unboxing, almost everything was neatly in its place. I noticed two oddities, however: the anti-static bag for the display panel was unsealed, open at one end; a piece of paper inside the box declared that the previous owner returned it as they had ordered it by mistake.
After assembly, I powered it on, but the display panel won't show anything but a blue screen. Reached out to the eBay store, who shipped out a replacement panel noting my observations above. Replaced the panel today, and there's no change in symptoms.
After powering it on, the extruder's fan spins, as does the power supply fan. The motherboard's fan does not. Display panel goes blue, without text. Pressing the button results in a beep on each press. I pulled the cover off the motherboard, and noted activity on two LEDs. After powering on, one near the fuse (labeled D3) lights up solid blue. The other, near the CPU (labeled O5), blinks twice quickly, then a long pause, followed by three more blinks. No idea if that's meant as a diagnostic code.
Nothing seems out of place when performing a visual inspection of the motherboard. Each connection is glued down, no scorch or blown components. I've tried updating the firmware, to no effect.
Board version: 4.2.2 CPU: GD32F303 RET6 Sticker on the MicroSD slot: H8
Waiting on the reseller to get back to me with their next steps, but I'm not expecting anything until the work week starts up. Any thoughts as to additional steps I might take while I'm waiting?
Update: reseller is shipping out a new motherboard to me.
Final update: new motherboard resolved the issue. I'm printing!
I would try a firmware update again. Both file name (it's gotta be something the printer has never seen before) and card format matter.
Reddit is annoying, but here's some more info: https://old.reddit.com/r/ender3/comments/i1jgg9/ender_3_v2_firmware_upgrade_bricked/
I'll do that. Should I be using the "Ender-3 4.2.2 mainboard (32bit)" firmware? I've read that the Marlin firmware isn't compatible with the GD CPUs, so I'm assuming the "Ender-3Marlin2.0.6HW4.2.2GD" won't work.
Update: support got back to me, with instructions to reflash using the latter firmware. The symptoms changed: during the firmware "upgrade", the 05 LED flashes about once a second. I let it run for ten minutes, but the printer never rebooted. Powered it off, removed the SD card, powered it back on... Still nothing but a blue display, though the 05 LED keeps blinking once a second.
I'm thinking it's a bad motherboard. Waiting on support, now.
Good luck!