add some details to 'hitting enter does nothing'

Author: asinn826

articles/virtual-machines/linux/serial-console.md

@@ -153,7 +153,7 @@ As we are still in the preview stages for serial console access, we are working
 Issue                           |   Mitigation 
 :---------------------------------|:--------------------------------------------|
 There is no option with virtual machine scale set instance serial console |  At the time of preview, access to the serial console for virtual machine scale set instances is not supported.
-Hitting enter after the connection banner does not show a log in prompt | [Hitting enter does nothing](https://github.com/Microsoft/azserialconsole/blob/master/Known_Issues/Hitting_enter_does_nothing.md)
+Hitting enter after the connection banner does not show a log in prompt | Please see this page: [Hitting enter does nothing](https://github.com/Microsoft/azserialconsole/blob/master/Known_Issues/Hitting_enter_does_nothing.md). This may happen if you are running a custom VM, hardened appliance, or GRUB config that causes Linux to fail to properly connect to the serial port.
 A 'Forbidden' response was encountered when accessing this VM's boot diagnostic storage account. | Ensure that boot diagnostics does not have an account firewall. An accessible boot diagnostic storage account is necessary for serial console to function.
 
 

articles/virtual-machines/windows/serial-console.md

@@ -170,7 +170,7 @@ As we are still in the preview stages for serial console access, we are working
 Issue                             |   Mitigation 
 :---------------------------------|:--------------------------------------------|
 There is no option with virtual machine scale set instance serial console | At the time of preview, access to the serial console for virtual machine scale set instances is not supported.
-Hitting enter after the connection banner does not show a log in prompt | [Hitting enter does nothing](https://github.com/Microsoft/azserialconsole/blob/master/Known_Issues/Hitting_enter_does_nothing.md)
+Hitting enter after the connection banner does not show a log in prompt | Please see this page: [Hitting enter does nothing](https://github.com/Microsoft/azserialconsole/blob/master/Known_Issues/Hitting_enter_does_nothing.md). This may happen if you are running a custom VM, hardened appliance, or GRUB config that causers Windows to fail to properly connect to the serial port.
 Only health information is shown when connecting to a Windows VM| This will show up if the Special Administrative Console has not been enabled for your Windows image. See [Access Serial Console for Windows](#access-serial-console-for-windows) for instructions on how to manually enable SAC on your Windows VM. More details can be found at [Windows Health Signals](https://github.com/Microsoft/azserialconsole/blob/master/Known_Issues/Windows_Health_Info.md).
 Unable to type at SAC prompt if kernel debugging is enabled | RDP to VM and run `bcdedit /debug {current} off` from an elevated command prompt. If you can't RDP you can instead attach the OS disk to another Azure VM and modify it while attached as a data disk using `bcdedit /store <drive letter of data disk>:\boot\bcd /debug <identifier> off`, then swap the disk back.
 Pasting into PowerShell in SAC results in a third character if original content had a repeating character | A workaround is to remove the PSReadLine module. `Remove-Module PSReadLine` will remove the PSReadLine module from the current session.