How can i do if no output occurs on the console

Possible Causes
1) Console setting errors (baud rate, flowcontrol, and COM port) on the host
2) Console cable damage
3) PC system faults
4) Switch software faults, causing processcrash
5) Switch hardware faults (forexample, faults of stacking modules or cables causing switch crash, and faultsof console-based circuit)

Troubleshooting ProcedureStep1: Check whether flow control is disabled on theterminal management software (SecureCRT or Hyper Terminal).
If the setting is incorrect, correct andsaved it, exit and the restart the software. Flow control is enabled by defaulton the SecureCRT. Disable flow control when setting parameters.


Flow control is disabled on the HyperTerminal by default. If it is enabled, reset its default setting.
Step2: Check whether the COM port is correct.
Right-click My Computer and then choose DeviceManager > Ports (COM & LPT).

The COM port needs to be the same as theserial port specified on the Hyper Terminal or SecureCRT.
Step3: Change the baud rate to 57600 or 115200 to checkwhether the fault is rectified. The default baud rate is 9600 on the consoleport.

If the fault persists, go to Step 4.
Step4: Press Ctrl+Shift+6 and then enter x to checkwhether the console port is recovered.Step5: Check whether the device can be accessed throughTelnet and check with the customer about whether services are operational.
If services are operational and the devicesupports Telnet, run the following commands under Telnet (no risk) to identifythe cause for no output on the console terminal:
Ruijie#debugsu
Ruijie(support)#tech-supportpackage
After information collection, run the clear line console 0 command to recoverservices. If the services are not recovered, collect information and contactRuijie technical support.
If services are operational but the devicecannot be accessed through Telnet, run the following commands to identify thecause for no output on the console terminal:
Collection poses highrisks (@@@@@ may even cause network interruption). Before performing thefollowing operations, clarify the risks with the customer and collectinformation when no service or service risk is available.

Connect the faulty device to the consoleport.
Run the following commands in sequence. Ifthe customer wants to recover services, restart the switch whether thecollection is complete or not. (4Esc indicates pressing the Esc button for fourtimes.)
4Esc +b        : reboot
4Esc +d        : debug_show_all_locks
4Esc +c        : open and close console
4Esc +f        : dump tech-support info
4Esc +h        : help
4Esc +i        : dump cli debug info
4Esc +j        : dump irq info
4Esc +k + pid + #  : kill pid proc
4Esc +l        : dump start process
4Esc +m        : dump mem info
4Esc +n        : start hrtimer
4Esc +o        : stop hrtimer
4Esc +p        : close logging message(sameas: no logging on)
4Esc +q        : dump context switches andruntime
4Esc +r        : dump other cpu dump_stack
4Esc +s        : show 5@ info
4Esc +t        : show task states
4Esc +x        : start dot task
4Esc +y        : stop dot task
If the devices are in a VSU system, run thefollowing commands on each standby device:
@@@@C
Ruijie#debugsu  
Ruijie(support)#tech-supportpackage
After information collection, submit cases to the case portal for further troubleshooting.