--- xserver-xorg-video-intel-2.1.0.orig/src/i830_display.c
+++ xserver-xorg-video-intel-2.1.0/src/i830_display.c
@@ -507,6 +507,9 @@
 static void
 i830_crtc_dpms(xf86CrtcPtr crtc, int mode)
 {
+    //this function is a matter of hanging the system when an external monitor is not connected,
+    // it is necessary to verify its existence
+    return;
+
     ScrnInfoPtr pScrn = crtc->scrn;
     I830Ptr pI830 = I830PTR(pScrn);
     I830CrtcPrivatePtr intel_crtc = crtc->driver_private;