(Now for the solution! If the info is badly formatted, sorry...this website may not handle white space appropriately.)
SOLUTION:
This specific solution is for an RCA VCR, but give it a try for other vendors and models.
The RCA or child lock feature [tradmarked as Pro-tect Plus(TM)] is controlled absolutely via the RCA remote control unit. The setting can be very easily activated by accident without any clear indication of what you did to cause the change.
My specific model is an older RCA model VR629HF, but this issue is similar across multiple RCA models. No override method appears to be documented, if such override exists at all.
However, even new RCA remote control units seem to work well when paired with older RCA players, as I have recently replaced a worn-out RCA remote unit. If you have another vendor's product, simply try the steps below or search for "Child Lock" or "Protect" on your vendor's product support pages for your model.
(1) Enable/Activate the child lock - Point the RCA remote control at your VCR and press and hold the VCR (or VCR-AUX, or even the ON/OFF as newer models offer both options). Hold the button for 6 seconds. "SAFE" is displayed in the status display window. The VCR appears to become an excellent boat anchor at this point. It is frustratingly disabled.
(2) Disable/Deactivate the child lock - Repeat the procedure in Step 1 above. The same procedure is used toggle the feature on or off.
IF THE REMOTE DOESN'T WORK, YOU'RE TOAST! So, please read on to make sure your remote is working.
If Step #2 above fails - as in my case - the remote control unit may have gone temporarily bonkers.
(3) Make sure your remote control batteries are good!
Dead battery = no service
Weak battery = questionable service
(4) Remove the batteries from the RCA remote.
(5) Wait 30 seconds or longer. Reinstall working batteries. The remote control should (may?) reset itself to its default, factory settings. The factory settings then should work with your RCA equipment, but you may have to reset the key codes for the remote.
In my case, the battery removal trick worked and the factory setting was fine for the VR629HF VCR, but I did have to reprogram codes lost for my non-RCA DVD and TV sets. Minor issue after the previous headache!
Hopefully, this adventure will help someone else along. Cheers!
Dave, December 2005