[ZyXEL] [NR7101] Boot problem with unusual LED sequence

Hello there!

Recently I've got myself a ZyXEL NR7101 - quite a bargain, but with one flaw I though I could fix. The device can't boot.
After connecting PoE cable I've got following LED sequence:
on (1 s), off (1 s) - three times
then on (0.5 s), off (0.5 s) - five times
then it stays lit for about 15 s.
After that it just keeps blinking on for a sec and then off for a sec.

So I was dying to check its serial port. Here's the bootlog.
(pardon me for that pastebin - I'm limited to 32000 characters :c)

First thing I was trying to do after getting this was to interrupt boot sequence with 'enter' key. Didn't save that particular bootlog but - no surprise - nothing happened :c
I was curious if zycast would do the trick, because the device awaits multiboot frames, but still - no effect. I've picked the Snapshot version - as per instructions posted here.
I've even tried to sniff for those frames to check if my setup is fine - an I've received a boatload of frames on my sniffer PC.
Next thing that came to my mind was to try to connect my linux PC with NR7101 through a passive switch to see if there is any traffic on ports - PC port keeps blinking, ZyXEL port - dead.

Personally I think that the port controller might be broken - NR bootloops after beethlink init, plus it does nothing during multiboot listening. Did anyone have a similar problem, or knows what that bootlog means? If it really is a problem with port controller I can have it fixed right away, but I don't know if it's worth bothering.

Best regards!

I agree. This looks like something is wrong with the switch. Your log is pretty much the same as mine up to that point: https://openwrt.org/toh/zyxel/nr7101#oem_bootlog

But I get a
[ 14.208000] MT7530 Reset Completed!!
where you have
[ 14.296000] MT7530 Reset Timeout!!

I guess that means broken hardware. Unless it's something very obvous, there's probably not much you can do about this.And the router is pretty useless without ethernet. Input to the bootloader is locked down by default. You need to set the "DebugFlag" variable to enable it. And there's no way to do that without either a booting system or the ZyXEL "multiboot".

Maybe remove the broken board and use the enclosure with wwan antennas for some DIY project?