Anyone ever have this problem before with their underpinner and if so what to do about it is what I am after.
My underpinner will not shoot. If I change the cartridge out from a 1/4 inch yellow one to another, and then place back the same yellow one. it will not shoot.It seems that the plunger does not sit against the "V" tp apply the needed pressure. Ther is slop of about 1/4 to 1/2 inch.
Waisting a lot of time and "V"nails this way.
Any ideas out there..
What kind of v-nailer? I had a Casesse(sp?) that used the cartridge style v-nails, and once every great while I had to disassemble and clean the block because of crud build-up. It would keep the v-nails from nesting in the receiver properly so it wouldn't work.
You might have an exploded view of the receiver in your manual or can get one off the internet.
Whatever brand of underpinner you have, there are two common causes of fasteners not shooting, assuming you have an adequate quantity of them properly loaded:

1. Globs of glue residue in the works. As Wally suggests, rouine cleaning fixes this one.

2. Slop in the pneumatic cylinders or friction surfaces, generally caused by lack of lubrication. The life of anything pneumatic depends on the quality of air that drives it.

The air supply must be clean, moisture free, and lubricated. If you do not have a lubricating mechanism on the machine, it is necessary to release the air supply and inject a couple of drops of pneumatic oil every week or two.

If you do not have an air filter on or very near the machine, harmful moisture and debris can collect in as little as ten feet of air line.

If cleaning does not solve your problem, check the looseness of your pneumatic cylinders. They can be replaced if needed, but if maintained properly, should last at least a decade or two.