B737-700
Flight Crew Last 90 Days 197; Flight Crew Type 4500
Troubleshooting; Confusion
Aircraft Equipment Problem Critical
Aircraft Equipment Problem Dissipated; Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport
Aircraft
After takeoff we began to experience issues with the instruments/navigation.  At approximately 400 FT AGL; the pitch mode dropped out; causing the flight director to disappear.  The aircraft roll mode automatically went into HDG.  At about this time; I noticed that the Captain's Navigation Display (ND) started blanking out intermittently; just for a few seconds or less; for approximately one minute.  As this was occurring; my ND also began doing the same thing.  We leveled off at our assigned altitude of 3;000 FT; and everything seemed to stabilize.  The displays returned to normal and the instruments appeared to be reading true.  There were no cautions/warning to indicate any continuing problems; so we proceeded.  We continued our climb as instructed.  At approximately 12;000 FT; we began to experience the same issue with the ND displays again.  This time we were presented with a DISPLAY SOURCE annunciation on both sides.  We ran the QRH for the item and checked all of our DC and AC power sources; which all appeared normal. The DISPLAY SOURCE message cleared before we even were able to complete the QRH checklist.  The ND displays were once again back to normal and stable.  At 18;000 FT; when changing the altimeter setting; I noticed a brief intermittent freezing and releasing on my altimeter.  It only lasted for about five seconds and then seemed normal once again.  We continued the climb.  At approximately 30;000 FT; the ND displays once again began to flicker and blank out.  This was almost immediately followed by both the upper and lower engine instrument displays also blanking out intermittently.  I watched the engine displays closely; and they were not blanking out entirely at once. Only some of the gauges were blanking out at a time initially. Soon; however; those screens also completely blanked out.  At this point the PFDs also began blanking out intermittently.  All six displays were flashing on and off for a few seconds at a time.  At one point; I witnessed all six display screens black at the same time.  After a several moments; the screens returned to normal.  We made the decision at this point to return.  During our turn; the screens began blanking one last time; just for a few seconds.  After that; the displays remained on and normal for the remainder of the return flight. The Captain stated repeatedly that the HUD display was true and correct throughout the incident.  We were in night VMC conditions the entire time.
B737-700 First Officer experiences intermittent freezing and blanking of display screens from takeoff to FL300 where the decision is made to return to the departure airport. During the turn back the screens blank one more time then operate normally to landing. The HUD functioned normally the entire time.