The Hobart Handler 140 (500559) runs the H-9 gun, and its feed problems split into two groups: things that kill the feed completely (a tripped thermal cutout or the voltage switch knocked off a tap) and things that make it drag or stall (liner, collet, tip, tension). The Handler shares its H-series gun consumables with Miller's M-series, so parts are easy to get. Below are the causes Hobart owners and Hobart's own techs report most, with the test that tells them apart.
Wire feed AND weld output both quit during a weld, the fan keeps running, and nothing is mechanically jammed at the spool or gun. It comes back on its own after a rest.
This is the thermostat protecting the transformer, not a feed fault. Leave the machine switched on so the fan runs and let it cool 10–15 minutes — it resets itself. To stop it recurring, stay inside the duty cycle (the Handler 140 is rated 20% at 90 A); long beads at high settings trip it.
No wire feed and no output at all — often right after moving, tilting, or bumping the machine.
The Handler's voltage selector must sit squarely on one of its tap positions; knocked off the detent (easy to do when repositioning the welder) it cuts both output and the feed circuit. Click it firmly onto a tap and feed returns.
Use Hobart's own test: disengage the drive roll and pull the wire out the gun end by hand. It should pull with little effort. If you can't budge it, the liner is the restriction.
Replace the liner — the Hobart .023–.035 in. × 15 ft liner fits the H-series (and Miller M-series) gun — and trim it square to the gun's length per the manual. Owners report a roughly $23 liner and 15 minutes clears a feed problem they'd chased for weeks.
Sight the contact-tip bore for an oval or arc-marked hole, and check the collet/adapter that retains the tip for wear or looseness.
Replace the contact tip sized to your wire — genuine Hobart 770177 for .030 (H-series tips). One owner's persistent feed issue turned out to be a worn collet, a simple, cheap swap once the tip checked out.
Rolls turn but wire slips (too loose) or birdnests at the inlet (downstream jam plus pressure). Check the roll's marked side.
Set tension with the half-turn-past-slip method. The Handler's drive roll is double-sided (e.g. .024 / .030–.035) — run the side stamped for your wire, and turn to the knurled side for self-shielded flux-cored wire.