Need Help with vendo-VF128

[dljm40]

     Hello all. Newbie here, after reading and searching I finally came tho the conclusion that I need help .  I made my own free vend momentary switch (Thank you jonnieG) for my Vendo VF128.  After installing the switch I push the momentary switch and you hear a click, I then try to make a selection and nothing happens. There's 5 cans in each of the selection and the "out of product" switches are all held down by a can. While looking in the relay box when I push the button, only the square relay activates, the other one "Sequence Relay Assembly?" does nothing. The serpentine system seems to work smoothly when I manually vend a can from the vend mech..

[johnieG]

first, did it work with the coinmech in place?  If the answer is "Yes" then you should make sure that you've included the jumper from pins 1 to 7 as well as the push button from 1 to 3.

If the answer is "no" ( it didn't work with a coinmech in place, or you never tested it with a coinmech because it didn't have one or the coinmech never worked to begin with) then next you should check for loose connectors on the underside of the rack ( feeding all of those nice little micro switches)

to get to the bottom of the rack easily, unload the cans, (or jam them in place with a bunch of rags so they don't roll backwards & get pierced & spray soda all over) remove the two large bolts at the top left & right of the rack, (don't lose the spacers that go along with them.) loosen the wire-harness retaining clamp (if there is one)  pull the top of the rack forward & tip it out of the machine, the bottom is pivoted, but you'll need a box or a plastic milk-crate to support it, now look at the bottom & carefully inspect the switches for loose or broken connectors, this style of rack is notorious for cheap/brittle brass connectors.

[dljm40]

WOW, thanks for the quick response.  The coin mech. did not work when I got the machine.  So I just unpluged the Jones plug and made your momentary switch from pins 1 & 7, and pin 3, just like the diagram. I read some of your other post about cleaning out the bottom after tilting out.  I unpluged and removed each vend, cleaned and reassembled. Nothing was broken or dirty (sticky).

[johnieG]

I can see the rack has "paddle-wheel" style vending gates be sure to double check the vending "pre-load" switches as well as the "empty" switches.. if the rack is "ready to vend" you should see 120 volts on pin #7 to chassis ground. before you hit the free-vend button. if not, you have an open circuit  somewhere.

[dljm40]

Where might I find these "pre load switches"? I'll also look at what voltage pin #7 puts out prior to pushing the free vend button.  What does that other relay do that's in the same box?

[dljm40]

Voltage to pin #7 prior to pushing free vend = 32 volts. Still looking for the pre-load switches.

[johnieG]

Where might I find these "pre load switches"? I'll also look at what voltage pin #7 puts out prior to pushing the free vend button.  What does that other relay do that's in the same box?

sorry, about time to make dinner for me & my boy, but the one should be the credit relay, I'd have to see the schematic to determine the other.   if you push the top of the credit relay, it should self-latch, at which point you should be able to select a drink button, the other relay may be a time-delay to terminate the vending credit either after the selection has been delivered, or after a specific "time-out" has been reached in which case it may unlatch the credit relay.

I just thought of something else too, some of these earlier vending machines had a delivery switch somewhere about the bottle (can) chute exit, typically attached to the bottle door ( can door in your case) if it's not set correctly, (IE: the door is closed) it may interfere with a vending cycle too.

32 volts is too low, unless it's stuck in the middle of a vending cycle. the switches are typically located on the bottom/underside of the delivery tracks it detects a minimum number of cans in each column ( usually two or three minimum) about two -cans up the serpentine rack, the cans sit on it & tell the coinmech that there is enough product to vend, ALL of the columns must have at least 2-3 cans each in this type of machine.

[dljm40]

Thanks again johnnyg.  I just looked at the can door and didn't see any switch or wire at all.  I did unplug the machine and pluged it back in, checked the pin voltage again and found that pin 1 and pin 3 had 117 volts, pin 7 had nothing.  Sorry I'm not a very good electrician but what did you mean by a chassis ground?  Again there are 5 cans in each rack and it appears that all the switches have cans on them.

[johnieG]

chassis ground = one test lead to the metal of the machines body/frame, the other to the point being tested.

[dljm40]

Chassis ground, now understood.  Well I must have a open circuit like you said. Pin #7 = 0 voltage. Where might be a good starting point?