How to Troubleshoot the Mini-Weld Model 6 or 7 Airless Plastic Welder

This video will show you how to diagnose your Mini-Weld Model 6 (5600HT) or Model 7 (5700HT). You will need an Ohm meter.

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Click here: https://www.youtube.com/watch?v=GDz4jarLAJo

Replacement Parts for the 5600HT or 5700HT:

• 6012C Ceramic Core Assembly
• 6020 Temperature Control Switch

Video Notes:

• English Closed Captions have been provided for this video. Click on the CC button to turn them on or off.

Music Credits:

• "Sage" by Slenderbeats
  From the YouTube Audio Library

English Transcript:

I'm just going to explain how to diagnose any faults with the Mini-Weld Model 6 or Mini-Weld Model 7 airless plastic welders. They're a real simple tool. Other than the power cords, there's really only two components that can go bad that will cause it to stop working, and both are easily checked using a multimeter and just by measuring the ohms. The most common thing is the heating element inside the airless welder goes bad. That's a part that looks like this on the Mini-Weld Model 7. On the Model 6, it's a nichrome wire wrapped around a spool, so you can't just replace the core, you have to replace the whole cable and everything.

The easiest way to do this is just to open up the box here and make sure it's unplugged - you don't want to have your cords plugged into anything. And I'll unplug that, get it out of the way. And you're going to use just a small Phillip’s head screwdriver to unscrew the tiny, tiny screw on the side of the box. Alright, take that screw, open the control box, and in here you'll see there's a control switch and then just some electrical connectors. So basically, what we're gonna do is check the continuity of the circuit from the blue wire that goes to the heating element and the white wire - or well in this case it's gray - that goes to the switch. Sometimes you'll find that these are black and white, it doesn't really matter, same component. The easiest way to get these apart, you know, just kind of wiggle sideways and pull. They are pretty tight. I'm going to use needle nose pliers here. Unplug this, and this one actually doesn't have to come completely off; you just have to get some metal exposed on the tab. But the wire to the switch does need to be disassembled. Like that. Alright, so I'm going to take a multimeter. It's set on ohms. Alright, so “ohms” is the little upside-down horseshoe, and that's just testing resistance through the circuit. You're gonna test the heating element only, because there is a capacitor in the switch that won't allow you to get an accurate reading through the switch. On the Mini-Weld Model 7 you should get about 53 ohms, plus or minus three. If it's a little bit out of that range, don't worry about it, it'll still work. If it's not showing any continuity, of course, then it'll be a bad heating element or bad wire. Okay so I've got this set on ohms. I should also mention on the Model 6 welder it'll be about 176 ohms. Alright, so I'm just going to take one contact and put it on the tab right there. Alright, and then I'm going to take the other one and I'm going to put it on the tab here. Alright, so you see this welder is not showing any continuity through that circuit. So what that tells me is that, you know, there's something between here and the heating element that would cause this not to work.

Alright, so in order to replace the heating element, and also you can double check the heating element in here, you're just going to unscrew this large nut, and you can usually do that by hand. Unscrews like that, pull that off. Pull your little spacer out. And then we're going to remove the three screws here. You can use the same screwdriver. Okay, once you have those three screws out, you just remove that, and then in here you've got a ground spring. Okay, so what you can do is you can push the cord and everything up through the handle. And the ground spring, it just plugs in. There's a little tiny connector there. Just unplug that, slide that off, and then your heating element just pulls out like that. And so you can see this one's been used. I'll double check this just to make sure it's not something else. I'll put the contacts on the heating element. And so I've got 54.2 ohms. Okay, so what that's telling me is that, you know, the fault in this is somewhere in here or it was just a loose connection. And that does sometimes happen. You can also see that this is twisted. This will happen if somebody tries tightening the tip without holding the flats of the heating element. So it can spin it around, and that that can actually cause a short sometimes. So I'm going to untwist that. And, actually, I think I found the fault. You've got this connector here that is not fully seated inside the housing. I'm going to push that in, and it's snug now. Yeah, all I'm going to do is reconnect that. Slide this insulator back down. Alright, I'm going to slide this spring back on, reconnect it. So that's your basic assembly. I'm just going to pull it back down through the handle. And this ground spring is just used to make contact with the metal part here, and that grounds the whole thing in case you have a short.

Alright, so while I'm doing this, I'm going to talk about the switch. And, you know, if you were to do a continuity check through the switch, depending on the position of the switch sometimes it'll show continuity, sometimes it won't, you'll get kind of a random resistance reading. And it really doesn't tell you whether the switch is good or bad. So to determine if the switch is bad, you know, you're just going to rule out the heating element. If the heating element is good, the wire checks out good, then you know it's the switch. Alright, so I've got those three screws in. Reinstall the spacer here. Take my welding tip, put that back on, and this kind of fits down and over the element inside. Keep that from turning. Take some pliers and just give it a little snugging up. And there we go. Just going to double check my continuity at the box again. And we're getting 54.7 ohms, so that loose wire in the handle is the fault. And I'm just going to reconnect this. Put the lid back on the box. But in case, let's say it was the switch, the switch is pretty easy to replace. It’s just two contacts. You pull the knob straight off, there's a nut there. Just unscrew the nut, pull the switch out, put new one back in, and put your knob back on. And get that sealed up. And put your plug back on, and there you have it.