737NG
After push back and checks completed illumination of Mach Trim Fail. Completed QRH and whith quick look at MEL as still on the ground it was ok to go with obivous precautions.
On requesting to continue taxi Speed Trim Fail light illuminated, again completed QRH and another quick look at MEL and was good to go.
I was flying so on line pushed TOGA and off we went. At Vr I pulled back and at that moment I lost my FD pitch bar and speed limit flag on my PFD and another master caution this time with Auto Slat Fail illuminated.
Reset the caution and continued the climbout and at N1 tried to engage Cmd B but it wouldn't engage so selected Cmd A and with flaps up into the QRH all whilst continuing with the SID. Whilst passing trhough FL080 my IRS decided it had too much and my PFD an ND went blank, A/P kicked out and was trying to fly and standby instruments. Eh you have control Capt!
We had already made the decision to return with the master caution after take-off since we now had 4 failures and more occuring.
Anyway upon landing and the enginneers coming onboard it was discover that the problem was due to one of the SMYD computers and was having clitches before take-off and according to the bite test failed at point of rotation.
What we learned from the event was that with the multiple failures was not to treat them seperatley and look at the bigger picture. Really comes down to keeping up with the tech side of flying and have since regularly went into the books to keep fresh.