I have a number of Camera for sale which are all new and boxed.
5no DS-2CD2555FWD-IS 2.8mm 5mp
5no DS-2CD2165G0-I 2.8mm 6mp Black
5no DS-2CD2123G0-IU 2.8mm 2mp
4no DS-2CD2723G0-IZS 2.8-12mm 2mp
2no DS2-CD2T43G0-I5 4mm 4mp
All Retail boxed all UK versions.
If your interested...
What you can do is try older firmwares for a 7600 series NVR with the flag set.
But as said above your NVR will still be Chinese with English text.
But as your talking about a 4 channel NVR I wouldn't bother the English version is only £110
If you want a professional alarm system go with Texecom Premier Elite and add the smartcom.
Ring alarm kits are at best basic,
Pyronix wireless kit eat batteries.
Honeywell Galaxy is now over 20yrs old and limited by design.
Well all good fun but not necessary really, forcing a firmware that doesn't go into the NVR or a Camera will partly brick the device this is done on purpose to corrupt the stored user details of the device.
All new IPC come with a reset button so this is only on older models.
Once you have...
recheck that you have pins 3 and 6 split correctly.
A cheap tester will show all cores are correct when they are not, you should be working to 568B standand.
Also check that the cameras rj45 socket pins are not bent up
The only time I've see skipped frames is when people use crap hard drives in their NVR.
only use a digital video hard drive like a western digital purx40, or similar.
my personal choice is to avoid Seagate due to high levels for failure.