Repetier host randomly not working?

Have you checked to make sure you have the right port?
Also, what operating system?

I've been having problems with the new version of Repetier also.  When I pause a print to change filament, I usually pause, lower the bed to prevent  blobing on my part, change filament and restart, and it starts printing in the air, bed does not return to print position.  Has happened several times, and is very frustrating.  Anyone else?

I don't know if this will help you, but if you go into the new Repetier, go to slicer menu,  look down at the filament part, to the right is a button called setup.  You can point Repetier to use the slicer version you want in there.

i tried to upgrade today too  i couldnt connect either! 7 x64 here too

oh well i at least upgraded from 0.82 to 0.85

Just tried that, isn't working still.  Also 0.85 works on 115200

Yeah, I do.  So is there anything else wrong in the settings?  I might give reinstalling the repetier host a shot.

Well, my luck must be continiuing.. I'm a big (ab)user of Slic3r beta's and releases, and ditto Repetier-Host (i think I posted the last 3 update posts )... and I have never contemplated going backwards.

My only suggestions are: DONT drop baud rates - it needs to be 250000 - If it 'fixes' anything its a placebo at best. It isn't the underlying problem, and will cause you mucho grief later with random mysterious print pauses and 'lost' layers...

Your firmware is expecting a baud rate of 250000 - the fact it 'works' at 115200 in older versions is simply a coincidence.

The repetier-host software isn't 'selective' in that if it worked one day, it will continue to work the next. If it doesn't, then something *else* external has effected it. I can say this with some level of certainty because I run 2 different versions, on 3 platforms, across 4 printer controller board types...

What does your Device Manager say about the device when you have it connected ?
Do you have multiple repetier hosts running but minimized (I do this a lot, and it will cause 'non connection' because the com port is already in use ) ?
Do you get errors in Device Manager connecting the device to windows ?
Do you get errors in Event Log about serial comms issues when you try and connect in Repetier-Host ?

You can uninstall everything and try again, including ditching your entries in registry (windows) and preferences list (mac). But your issue sounds more like a simple comms-driver/windows problem... With ONE exception - if you have the New Printrboard clone controller, there *is* an issue with Repetier 0.90, but this was fixed with 0.90B and is a non issue in 0.90C . If you have 0.90C, this is NOT the problem (the printrboard comms issue)

As to MolecularConcepts question: Inside Slic3r Config (not repetier) , go to Help Menu, select 'Check for Updates'.  If you can't see this entry in Help, find your slic3r.ini file, and uncomment the commented entry 'Check for updates=1' or whatever it says specifically - SD in their installers disabled this which means if you first installed their software then you may no longer see the update entry (as subsequent installs will retain your initial .ini config).

I'm also having problems with version .90c of Repetier host. Mine will randomly freeze and crash during a print. It will stop the printer while printing and just sit there with a (not responding) up at the top until I force quit repetier host and restart the program. Of course this ruins my prints. This has never happened before this version.

Oh.  DTR needs to be set to disabled.  Okay then.

Make an issue on RH's Github page. I believe there are a few random crashing bugs on Windows XP.

Might be a tad late on this reply, but I had an issue with not connection on V0.95F... I had to make sure I completely uninstalled everything on the old repetier host, including the files in Program Files, and I also had to make sure the Reset on Connect option was set to disabled.