My computer won’t switch on!

Diagnose, fix it yourself in 5 minutes

These are the things you can do to troubleshoot this yourself. After each of these steps, press the ON button to test again. Diagnosis is only effective if you do things one at a time.

1. Press EJECT on the CDROM see if any mechanical sounding action results. If it ejects or tries to eject then power is probably OK, but the Operating System has crashed, or else the monitor is off or disconnected.
2. Check there is a light on the monitor / screen. If not then test with a different monitor.
3. Disconnect ANY USB devices (including Keyboard, Monitor, External USB disk, Printer etc)
4. Completely disconnect power plug. Wait 20 seconds. Reconnect.
5. Test another device with the same power cable / wall socket to ensure it is live.

Call your IT support. Make a note of the following findings to help them assist.

1. Do you hear any noises or see lights flashing briefly anywhere on the machine at the moment you plug it in?
2. When you attach an Ethernet cable between the Ethernet Wall Socket (if you have one) and the Ethernet socket on the machine, are there any lights?

If your organisation has no IT support, we may be able to help.

For the confident or the brave

If your willing/able to open the case and get under the hood you can probably get to the root of the problem yourself! Firstly
ensure that the power supply is live as per instructions above (must be some lights or noise when you plug in power). Sometimes a faulty peripheral can stop the machine from starting up so lets try to disconnect them all. Again it’s important, after each step below, to test the ON button again.

1. Open the case – on most modern machines you don’t need tools
2. Disconnect the CDROM
3. Disconnect the Hard Drive
4. (advanced only) Disconnect all the memory modules. Be very careful not to handle with un-gloved fingers the gold/silver strips on the modules. If response to power-on changes then probably you’ve got a faulty one. In this case, place them back in the machine one at a time repeating power-on test each time. When re-installing press firmly and gently, don’t forget to ensure the holding clips are closed properly. When behaviour changes you’ve probably found your faulty SIM. You can get like-replacements from https://crucial.com/ or contact us for a quote.

master ssh keys

Use ssh to run scripts on remote servers without entering a password.

Create your ssh key


ssh-keygen -b 4096 -t rsa -f ~/.ssh/keyname.rsa


will produce a keypair. The .rsa file will be the private and the .rsa.pub is the one that goes into authorized_keys on the remote server. If you don’t enter a password the key can be used with no user interaction. Do this when you need script operations on a remote server.

Load a key


ssh-add keyname


Upload your ssh key to a server


ssh-copy-id -i keyname.rsa.pub username@remotehost


Carry your key with your ssh session

if you need to carry your key somewhere, for instance if you will be chaining through to a host WITHIN the network of your remotehost and there is no direct ssh port forwarded to that host.


ssh -v username@remote -A


using -v (verbose) can help diagnose connectivity issues

Display the ssh keys you have loaded


ssh-add -l


if you forgot to carry a key or you need to add a local key you will get the error:


ssh-add -l
Could not open a connection to your authentication agent.


in this case use


ssh-agent bash
ssh-add keyname


Using alternative ports

Sometimes your remote host is running ssh on another port since 22 on that IP is already used. To reduce brute force attacks on the standard ssh port you can also use alternative ports by setting up the listening port in sshd_config on the server.

Use the -p flag to specify:


ssh -p 41843 user@remotehost


You can use an -i flag to specify a key to use (always needed in bash scripting for using ssh password-less)


ssh -p 41843 -i ~/.ssh/keyfile.rsa user@remotehost


If you manage many servers you may want to use ~/.ssh/config to alias the connections.


vim ~/.ssh/config
Host remotehost
IdentityFile ~/.ssh/keyname.rsa
Port 41843
ServerAliveInterval 240


In the case above you can simply use ssh user@remotehost to get in using keyfile.rsa on port 41843

How to forward email in Zarafa WebApp

1. Click Setting top-right.

2.  Click Mail Filters to the left.

3. Create a rule.  When the message is sent to … you (choose your name) and click the To: button in the Address Book

4.  Do the following…  Forward the message to… either choose from Address Book and click To: or enter external address in To: field

5.  Tick Stop processing more rules

6.  Click Apply