But playing music via itunes works?
Yeah! I pretty much use my iTunes everyday… Can anyone help me? 
Are you runing Cubase only? Can you try to switch all your other applications off?
Once again. Turn the controll room completely off please… and try then. There is a blue button in the upper right when you are on the studio page of the VST connection. Click it so that it turns grey.
Best regards.
If you switch the Control Room Off, you have to change the setting of Outup. Set Main output in the Output tab of the VST Vonnection.
This thread is kind of funny in the sense that it’s trying to tackle a bunch of things individually. Anyone viewing the OP’s posted screenshots should clearly see quite a number of “new user” missteps going on…. leading me to suggest this to the OP:
Stop. Really. Just stop what you’re doing with that Project and trash it. Quit Cubase and start over.
Before you relaunch Cubase, do this:
Navigate to HD/Users[yourname]/Library/Preferences/Cubase 6.
Right click on the folder and choose: Compress “Cubase 6”. This makes a quick backup.
Throw the original folder into the trash.
Restart Cubase.
I am not a subscriber to the shotgun approach of trashing the entire Prefs folder, but in your case, I think this may be the best course of action because of what I can’t see in your screenshots. Clean Slate.
Re-launch Cubase. Do exactly what is shown here:
http://78cf01617e3950417f0c-edf74d1b5a4206a253d3389ccc6c1dae.r38.cf1.rackcdn.com/QuickStartVSTi.m4v
Before recording on the Track, double check these settings and make sure Built-In is selected:
http://78cf01617e3950417f0c-edf74d1b5a4206a253d3389ccc6c1dae.r38.cf1.rackcdn.com/DeviceSetup.png
http://78cf01617e3950417f0c-edf74d1b5a4206a253d3389ccc6c1dae.r38.cf1.rackcdn.com/VSTconnectOuts.png
Arm the Track and start recording. Can you hear your LM-7 track now?
jeeez…this is exhausting.
Before you trash it… Well, trash it. I trashed prefs quite often.
Only problem with trashing prefs happens with programs that use a library
like iPhoto and iTunes. Maybe rescan media bay afterwards.
BUT:
When it’s all about that plugin where is a picture of thee plugin UI?
When it’s all about that plugin where is a picture of thee plugin UI?
The LM-7 plug-in is a non issue. My little example uses the same plugin. It works on a Mac.
It would appear that the main issue here is that the OP has activated a lot of non-relevant elements all over the UI and is obviously not familiar enough with the program to realize that some or all of this extraneous stuff may be contributing to the problem: no sound getting to the MPBs internal speakers.
Let’s see what happens following what I’ve suggested, eh?
Hi, i think i know the main problem of my cubase! Does anyone have the link of where can I download lm7 plugins for mac? Thanks
To be true… No. Was the lm-7 a steinberg plugin?
Like the vb-1? I guess I remember it now and I used it
ages ago. Why do you want to use this plugin anyway?
So the problem was that the plugin wasn’t really there all the time??? 
This is what I get for assuming the plug was actually loaded in the 3rd screenshot the OP posted:
No1DaBeats was right to ask to see the LM-7s UI. I should have guessed the OP did not originally generate this Project file.
Here is the link to the Mac version of the plug-in and its companion presets:
ftp://ftp.steinberg.net//Download/Legacy_Additional_Content/Additional%20Cubase%20SX%20Plugins/Mac/Universal/Drums/LM-7.zip
This plug-in will work in at least 10.6.8. Beyond that, I don’t know. Put the two files here:
HD/Library/Audio/Plug-Ins/VST
Who’d have guessed that? The Audio Outputs of the plugin are still visible in the project
window. Shouldn’t happen. Strange thing!
Facepalm!
Everyone wants project interchangeability - and you think Cubase should delete VST Instrument channels of not found VST Instruments? How would you ever know, what Instrument was used originally with what EQ / Insert settings, if Cubase simply deleted the Channels…?
True. Didn’t think about it. I never exchange projects.
THANK YOU! you’re a lifesaver! It finally works!! 
sorry for all the trouble everyone… rookie mistake 
Awesome. Thank you!