4.88 is a bit low. I just checked in clays guide and this is what is said. "+5 volts DC: TP2 (TP101 on WPC95). Should be 4.92 to 5.1 volts DC. If this is below 4.92 volts, the game will most certainly reset easily, as this is the voltage the "reset watchdog" examines."
There is more on this in the guide but i didn't copy it on here, I don't want this forum to get into any pooh over copyright issues.
I hope i am allowed to post that part of the guide here.

Its no problem, Andrew - as long as you quote the section and credit the author. Even a link to the section will suffice.