First thing, check the battery voltage. Set your multimeter to dc voltage, red probe on + pin of the battery, black probe on the - pin of the battery. If your multimeter have different voltage ranges, set to the one just above 9V (it's usually 20V). You should expect more than 8V from a healthy battery. That said, the 386 draws a good amount of current and you have two of them in the circuit, so I woudn't go for a battery. But anyway.
After you test the battery, plug it on your circuit. Since you used mono jacks (more on that later, let's first do some measures), you don't need to worry on plugging anything else, just the battery. Don't even worry on the switch. And btw, because of the mono jacks, the battery is drained as soon as you put it in the circuit, even you don't plug anything else.
With the multimeter still on dc voltage setting and the same voltage range as before, put the black probe on the ground connection. Any of them will do it. For example, the part of the jack that's connected to ground. Then, with the red probe, check both sides of D1. The side without the line should have the same voltage as the battery, the side with the line should have a bit less voltage. Then check pin 6 of both ICs, they should have the same voltage as the line side of D1. Also check pins 2 and 4 of each IC, they all should be zero. If you don't know how to tell the pin number, look at the ICs with that notch on the "upper side". On the left side you have pins 1, 2, 3 and 4 from top to bottom, and on the right side you have pins 5, 6, 7 and 8 from bottom to top.
Those voltages should give us some info to start the troubleshooting. If the doc had the expected voltages for each IC pin, we could measure them, but I really can't get the reason for not including the voltages on the doc.
And since you have a spare jack but not spare caps, not a problem (if you know what you're doing and we'll help you with that). You can build a tool called audio probe, which is one of the best tools to troubleshoot pedals. Get two pieces of wire, two different colors if possible (and black for one of them, if you have it). Solder one wire to each lug (black wire on the ground lug), and that's it for now. You'll improve it a bit after you get a spare cap. After you post the voltages, if those are correct, I'll guide you on how to use an audio probe.
