What your friend did was bypass the "start" position of the ignition switch by connecting battery power directly to the starter solenoid. The "solenoid" is just an electrical switch. Normally your ignition switch would send a bit of current along a Yellow/Blue (or is it Yellow/Red?) wire to that solenoid, and it then activates, connecting the large blue battery cable to the starter itself. That cranks the engine. Your friend's screwdriver just substituted for the ignition switch and Y/B wire.

If he knew how to do that, he may be able to troubleshoot further. The Y/B wire comes from the ignition switch through the firewall into the engine compartment. It's very unlikely there's anything wrong up to here. In the engine compartment it immediately goes into (and continues out of) a large Gray plastic connector, high up on the firewall above where your feet would be, with about 4 other wires. From there on, the wires of your year of 240 are infamous for crumbling insulation.

Check that wire. Unfortunately, if it's in poor shape, so probably are others and future electrical problems are possible. I was able to buy a good condition, used wiring harness for our 83. But fixing the Y/B should get you going for now.
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Bob (son's 81-244GL B21F, dtr's 83-244DL B23F, 'my' 94-944 B230FD; plus grocery-getter Dodge minivan, hobbycar 77 MGB, and numerous old motorcycles)