Help with VV circuit

[rshields]

I am trying my hand at my very first VV mod. To make the first attempt simple I chose to purchase this little VV kit: Variable Voltage Regulator Board Kit Rev 2

This circuit gives me a steady 1.3 volts output no matter what the setting of the pot is. I have examined my soldering job many times over and it looks good. I have tested continuity at every possilbe point to ensure that what is supposed to be connected is and nothing is shorted. I tested all the individual components (except the voltage regulator itself, which I don't know how to test) and it is all working per spec.

Do any of you expert modders have any suggestions as to what could cause this circuit to output constant 1.3 volts?

 

[Rockproof]

Don't take offense at this question but the simplest always have to be asked first...are you using two batteris stacked?

 

[TomCatt]

If you can, post some pictures and/or a drawing of how you have connected everything.

 

[WillyB]

Well it's giving you the standard reference output voltage ~1.25V.

Check the 10kΩ resistor (R1) and make sure it is in fact 10kΩ, you should also check your trimpot and make sure it's resistance is in the ballpark also and make sure it changes as you turn it. It seems your problem has to be in that part of the circuit.

There is a diagram in the datasheet.

 

[rshields]

Don't take offense at this question but the simplest always have to be asked first...are you using two batteris stacked?

No offense, it is a good question and I should have said to begin with. I am using two 14500 batts in series as power source.

 

[rshields]

Well it's giving you the standard reference output voltage ~1.25V.

Check the 10kΩ resistor (R1) and make sure it is in fact 10kΩ, you should also check your trimpot and make sure it's resistance is in the ballpark also and make sure it changes as you turn it. It seems your problem has to be in that part of the circuit.

There is a diagram in the datasheet.

I have put the pot on my DVM and verified that when turning the pot it ranges from 0 -50K. I also tested both resistors and they were will within tolerances.

 

[rshields]

If you can, post some pictures and/or a drawing of how you have connected everything.

Well, that would have been a good idea. Shoulda done that. But in all my efforts to figure out what is going on I have since desoldered all the components except the regulator and then soldered in some wires so I could connect it all to a breadboard and further play with the circuit (the format of the regulator prevented me from directly connecting it to the breadoard). I still get the same results and I redid all my continuity tests to prove valid connections.

EDIT: But as for a drawing, my connections were exactly as the "picture" provided by madvapes on the link in my OP.

 

[TomCatt]

Have you posted this over on the madvapes forum? If all the components you could test are as expected, consider ordering another regulator to check if that's the problem. MadVapes sells the regulator separately. Hoog and company at MadVapes are excellent, contact them and explain the situation; I'm sure they would work something out with you.