GSM Module SIM800L no working

I have a SIM800L module, but it cannot find the network(board LED blinking every second)

The SIM card was working fine on my phone

I'm sure the power isn't the problem, because I used 5v from Arduino board with a diode(drop voltage to 4.3v) and 4400uf capacitor, even tried with a 3.7v Lithium Ion battery

---> AT+CSQ
<--- +CSQ: 0,0
RSSI = 0: -115 dBm

---> AT+CREG?
<--- +CREG: 0,0
Network status 0: Not registered

---> AT+CMGF=1
<--- OK
---> AT+CPMS?
<--- +CPMS: "SM",0,30,"SM",0,30,"SM",0,30

---> AT+CPIN?
<--- +CPIN: READY

---> AT+COPS=?
<--- +COPS: ,(0-4),(0-2)

---> AT+COPS?
<--- +COPS: 0

---> AT+CBAND?
<--- +CBAND: DCS_MODE

how can I solve this problem, is possible that the module has broken?

sim800L is a pure 2G board, you sure your ISP supports 2G around there ?

KASSIMSAMJI:
sim800L is a pure 2G board, you sure your ISP supports 2G around there ?

I can get the 2G signal on my phone

try to set cband to dcs_mode,all_band

KASSIMSAMJI:
try to set cband to dcs_mode,all_band

I set AT+CBAND to ALL_BAND

---> AT+CBAND?
<--- +CBAND: EGSM_MODE,ALL_BAND

the SIM800L still cannot find the network

Looks like my country didn't support the 2G already...