It is important to note that the size of these machines limits the components and the capacity or production.
As in all channel style machines when the heat bar starts to warm up the ability for the pump to pull air out of the bag decreases.
These machines do not have a heat sink under the wire so this happens quickly. It is very important to allow time between seals. If you try to go too fast, the air channels in the bag iron out, and you cannot pull air over a flat surface (it won't suck).

This thing is not vacuuming the way it use to: This is sometimes caused by the "channel gasket" crushing down over the years. Try removing the gasket, and soaking it in a silicone lubricant. Use the stuff you apply on the dash board of your car, or the silicone that skin divers spray on the inside of their wet suites, to keep them supple. Keep the gasket out for a day or two to fluff it up, then reinstall it. ... or buy a new one!

I dropped it, and the thing that used to clip down broke off:Well we do have a repair for this, AND it does not look like new, but it does work. Glue is not the answer, it involves melting the case, and adding some plastic to rebuild the clip. ... Send it in, (it doesn't look too bad when we get done) or live without it. The first "Compact Foodsaver did not have a clip to lock the lid down.

My bags vacuum and look like they are sealed, and the air gets back into them after a few minutes: The most common occurrence that sends these machines in for service, is the heat tape, because the heat tape is glued to the heat wire. The wire expands and contracts. However, the heat tape does not stretch, so it has a tendency to buckle, or get a wrinkle somewhere along its length. This makes a cold spot on the heat seal, and then your bag has a leak. The only fix is, to send it in for a new piece of heat tape. We have found that removing the adhesive from the heat tape, and making a "zone" or track for the wire to travel in, will fix this problem. This is not a home repair, sorry!