By trial-and-error, I found that pressing the CANCEL button will wake the printer up.

I have the same problem - no response after sleep starts.

On my Mac, I can't even find the Status Monitor to extend the sleep time. However, extending the time would just delay the problem.

There must be a way to wake the thing up other than powering down and then back up!

I've tried that, didn't work for me.

Is there a way to disable the feature? as even if the cancel button did work it would mean having to press it to print something.

Is the firmware version 0.49? I have that version installed but it won't wake up.

I forgot to mention that I was trying to wake up using a PS310U usb sharing device which wasn't waking the printer.

I've now tried connecting it directly to a Dell/Win 7 PC and it's still not waking up.

I installed firmware update 0.49 - the latest from the Dell website.

My 1250c was purchased from Dell in January 2012 and did NOT ship with the firmware update installed. Nor was there any hint of an update in the package. I used the live chat to confirm that the printer was compatible with Mac OS-X before purchasing it.

After the firmware update, Apple OS-X, Windows XP and the top buttons wake the printer from sleep.

If your printer won't wake up from its Start or Cancel hardware buttons, it has more serious problems than firmware or drivers. I'd suggest a live chat with Dell support.

I changed to settings to Sleep: 5 mins, deep sleep 1 min and it now wakes when I press any button or try to print to it.

At least I know that's what it should do, so if it doesn't wake again I can get a replacement.

Thanks for your help Ronnieh1.

This post is a little old, but in case the OP or anyone else with a 1250 is having these issues I do have a few suggestions.  It is the only post that comes up regarding the 1250 sleep issue so rather than divide attention I will just attract Google searches to here.  If this post helps even a single person it will be worth the effort.

We use a number of Dell 1250's at my workplace many of which are deployed remotely.  Many of them have this same deep sleep issue that is described above.  If you call Dell Tier 1 Technical Support they will tell you that this is a design feature (going to sleep might be, but being unable to wake-up is clearly not).  It took about 7 phone calls and several hours, but I eventually transferred to someone from the Dell Imaging Life Support Team and from there was given a couple of possibilities for less obvious solutions.  The first solution did not apply at all in our case, but I am posting everything for the sake of completion in the hopes it may assist someone with a slightly different configuration.

Solution 1 for Networked 1250's.

Check to see if SNMP Status is Enabled

Printer Properties->Ports Tab->Configure Port->Uncheck SNMP Status Enabled

Solution 2 for all 1250's.

Go into Device Manager on the system that one of these printers are USB connected to and open up the USB controllers.

Then right click on a USB root hub and select properties. Under Power Management, make sure “Allow the computer to turn off this device to save power” is UNCHECKED. You can also check “Allow this device to bring the computer out of standby” if you want to. This either needs to be done to ALL USB Root Hubs, or, look for a power tab ,and that should give information regarding if something is connected to that Root Hub.

Please post if any of these things help.  Short of disconnecting the power nothing else has worked for us so far.  Firmware updates, power button, sending jobs to the printer, etc.  I was also told another "solution" would simply be to send a blank print job every hour before the printer goes into hibernate, but I am not going to suggest anyone actually do that unless they feel it is their best solution.

I will followup when I have some results.  Good luck folks.

An update on my post from 09/02/2012, the printer is still going to deep sleep and can only be used by power cycling. Dell sent me a new replacement printer which does the same thing.

Spectear - My printer is connected to a TP-LINK TL-PS310U printer server, with a Dymo Labelwriter 450. I've tried the two solutions you listed, but for the port I get a message saying it cannot be configured at this time. I'll try leaving it connected directly to a PC and see if that makes a difference.