ipcamuser11
Getting the hang of it
ipc_g0_cn_std_5-5-89_210429 this is the corresponding firmware associated with his serial number, should be correctBoth of these firmware files are on hikvision.com/cn
IPC_G0_CN_STD_5.5.88_200602.zip
IPC_G0_CN_STD_5.5.88_200610.zip
Make sure both were tried. I suspect it may not help though as one of them is in the 2XXX firmware package.