dede

Well, so change subnet to 192.168.1.x on your laptop

Just any USB-TTL cable, you can search it on ebay or just use one from old mobile phone. But i encourage you to do it via telnet, cause serial console will require some special skills and knowledge and there's a risk to break your DVR

It doesnt sound right. Maybe your PC is in the different subnet? has to be the same 192.168.1.x

If you still cant login, then you will need USB-TTL cable and you will have to connect to DVR console and do the same steps as with telnet

Check default IP in manual (should be 192.168.1.10 or 1.108 ). Or just use any IP scanner utility to find the address

Looking for a firmware or DVR name that has same boot logo (attached) and having slave board inside (2 SoC's)

Board name is DVR_MB_69 and DVR_MB_70 slave, both having GM8180 SoC's

Need contents of the "User" MTD partition, can share semi-broken fulldump, if someone needs (without mentioned above MTD)

Can you telnet into your DVR? If so, you can remove /mnt/mtd/Config/Account* and password will be gone