Colleagues,
We have a generic 8 channel DVR for which the Admin password was altered - then misplaced (maybe by me!).
The only identification was "36588V" on the bottom, and KW3298H on the PCB. Searching tracked it to Yiwu Kexuan Electronic Firm ( www.ywkexuan.appliances-china.com). They did not respond to a support query, but the site suggests the units may be branded "AN-TONE". Ours is not.
We did eventually discover the reset trick. Adjacent to a flash-ram chip on the board is a 2-pin 0.1" header marked "J-15". While the box is powered up, short the 2 pins for a few seconds. There will be a beep, and the Admin password is reset to the default "888888". The user account does not appear to be altered.
It's possible other settings may be wiped by this action, so it would be wise to note any custom configuration values beforehand.