'old' mac wont play well with others

[lone eagle]

running OS X on older desktop - been wireless for years on small company network - yesterday both the Mac, and 1 windows laptop stopped talking to the network. (seems a new sheriff came to town with a more powerful Wi Fi - must be a 1000 watts rig - na - just kidding - anyway - it over powers my in house unit) - a third unit (desktop wireless) continued working.
ran a temp hard wire to laptop to solve it's issue. hot dogs - I'm cook'n now.
ran hard wire to Mac - no talkie - we use the mac for graphics design only to drive a large digital press (big copier) only licensed program is on Mac. it sees and works on the internet just fine, meaning it is working off of our system connection, however, it does not see our system's backup hard drive or the big copier or any other machine - have looked at all of the setting that I could find to play with.
it sees the 'big copier' and says that it is not printing, but will not connect to it or see anything on the network,
running at least 5 - 6 machines at any given time
- have checked the ip address for the press, which is correct, have tried to connect using the web ip address, no go, having to do graphic layouts on different box which it taking hours longer but the trips with the flash drive
you will be added to my Christmas list if you can provide me with some help or a tip
i'm not really a Mac guy - and don't know the 'ins and outs' of the Macs - we use the mac because it came with the job, i'm more of a Boeing type of guy
thanks in advance for using your gray matter - and may the blessings of the 'Builder' be with you!

 

[Cory Cooper]

Hello and welcome.

A few questions:
-Which exact model Mac?
-What version of OS X?
-What changed in the network - the Wi-Fi router? If so, what brand/model and who installed/set it up?
-Do you have an IT department?

Sounds like something in the network changed and the settings need to be adjusted on the router, as well as the Mac.

C