Internet Problems

I work on iMac and use a router plugged directly by cable to telephone and my mac and I've been using the internet for years without any problems, suddenly the internet is working and then not working.
both the telephone company and service provider say all is good, but now i'm struggling to get onto the net and my mails come through sometimes.
does anyone have any suggestions? Please, i'm desperate.
thanks.

1. Do you have a router/modem combined or a router and separate modem.

2. If separate does the problem persist if you connect direct to the modem?

3. Are all internet services affected email, updates, different browsers?

4. Do you have any other devices that are or could be connected? Do they have a working connection?

Hi there,

one
2. If separate does the problem persist if you connect direct to the modem?

3.Are all internet services affected email, updates, different browsers?
yes, sometimes my mail comes through perfectly and sometimes it won't but sometimes I can get onto the internet but the pages won't load properly and sometimes I can't get onto the net at all.

4. Do you have any other devices that are or could be connected? Do they have a working connection?
nothing except a hard drive connected sometimes, but that's all.

: )

OK. It would be really handy to get a friend, family member or other willing volunteer to connect to your network with a laptop, tablet, phone and see if they experience the same issues.
That would tell you if the issue is with your Mac or the router/modem/supplier.

But there are some things we can try on your Mac. Most and routine maintenance type tasks, some more network targeted. Try you connection after each step to see if there are any changes.

1. Reset the PRAM/SMC
About NVRAM and PRAM

2. Download and install Onyx (choose the one appropriate for your version of OSX)
Titanium's Software • Index page
Once running choose the Automation tab and running every on that tab.

3. Log into the Guest user and see if the problem persists

4. Reset your Network Configuration

• In Finder go to yourMacHD/Library/Preferences/SystemConfiguration/preferences.plist
• Rename the preferences.plist to preferences.old
• Restart your Mac
• Reconnect to your network and try again.
• If that doesn't work then do the same thing but for the whole SystemConfiguration folder

thanks.

thanks, i'll try those things and get back to you.
thanks a lot.
chat soon