Programmer seeking help with breadboard for drink project!

Hello all, I'm currently working on a project that automatically dispenses drinks. I have a prototype built and you can see it here:

unfortunately some of the IC chips we bought are a little funky since they were $2 and ordered from a not-so-reliable source. The EE that is building the breadboard can't get the circuit to support more than 3 bottles at a time, and he can't figure out if its the arduino, the chip, or the schematic, or a combination of these factors. As we are both college students on a budget, we would like to build this as cheaply as possible.

Any ideas?

Thanks in advance

It's extremely hard to tell what's (not) happening without code/schematic.

Could be funky chips, it could use too much power, but there could also be something wrong in the schematic or code...

Right, I understand that it would be hard to tell what was going wrong without any information about the chips. We used a voltmeter to make sure the power from each pin to the breadboard was going high properly when the interface sent information over the COM port. unfortunately thats about all we know. the solenoids fire at 12 volts, and the voltage supplied from the arduino is 5. We're pretty sure the chips are the cause of the problem because we ordered 12 and 9 of them are known defective. The problems start occuring when you add more than three channels. Also, the code doesnt allow more than one solenoid to fire at once.

I guess what i'm asking is: do you know of any chips or any schematics that could handle 10 channels in parallel? in I would like to word my question with more aptness, but unfortunately breadboards are almost completely black boxed from my perspective. I am asking on behalf the EE

Thanks

Well if the chips die, you may have forgotten to add the free-wheeling diodes across the coils of the valves.

As you don't tell us what current these valves need, it's quite impossible to recommend a certain chip (well except to use beefy mosfets which won't die, but that may be overkill). The pure hardware aspect of your project is perfectly doable and not difficult at all.

More data!