Here's a few things you can try...
The heck with those tests.
You can't get parts in time anyways.
1]Try jiggling around the connectors going to the bill acceptor.
Could be a loose connection or an oxidized pin.
Spray some electronics contact de-oxidization cleaner spray
into the connectors, blow dry them and shove them back in.
The pins are probably straight because you didn't take the connectors off.
Or did you?
If you did...one is bent now.
Find it and straighten it out.
2] Take out the cash box and push it back in fully.
2.5]Take out the cash box and push it back in fully...
but this time, make sure the screws are tight.
3] Check the transport out, blow some compressed air into the
sensor holes and whatnot. Do NOT use any alcohol wipes.
They only cloud up the optics and make things worse.
4] Bang on the left side of the cash box and big bill acceptor bracket.
5] Clean any optics with more compressed air on the transport.
Now put the dip switches back where they were before
you started fiddling around with them.
They worked before, they will work again.
You and I have no idea what they do but I never touch them.
Power up the machine and cross your fingers.
That's all I care to know about DBV's
and one of these usually works for me just about every single time!