Parweld XTI160DV

[RyanCollins]

Hi all!

Looking for some help. A friend of mine asked me to see if I could repair his XTI160DV. A component has blown and I can't identify it. I contacted parweld as the were helpful in the past, sending me schematics and service manuals, but they're not sending me anything helpful this time!

If someone here has the same welder, could you send me the details of the dead component!?

I've attached photos, the culprit is circled! Hard to tell from the photo, but it's popped, only the heatsink is left!
Thanks, Ryan

 

[MoreWellie]

Solely by looking at your picture it will probably be either identical to the transistor/triac/thyristor/fet that is just to the left of your red circle. Either that or the complimentary transistor (NPN PNP pair)

it looks to me like you might have had an exploding electrolytic capacitor given all that gunk as from my experience semiconductors just crack/fragment

These are the ramblings of an electronics person not someone familiar with that welder

 

[Richiew]

I have one. I'll try and get you some pics over the weekend.

 

[Richiew]

Not sure mine is the same as yours as I don't have that piece of frame running along the length of it. The electronic gubbins look different to my eye too. Anyway, here's a few pics. I'll get more for you later if needs be. Disclaimer, I know very little about electronic components.

 

[D B]

Hi Lads, I have a Parweld inverter that **** itself recently. XTI 161 DV model. I was using it recently, had the machine on while I was prepping & I heard the fan shut off. Then when I went to strike an arc, got nothing, not even a spark. LED light on the power button on the back is still working. I opened the welder up to have a look to see something obvious, no loose connections or burn marks on the cards, so I’m stumped. Any ideas on what might be the issue greatly appreciated. Thanks.

 

[eddie49]

Hello, and welcome to the Forum!

Is the machine still under warranty? If so, contact your supplier or the manufacturer and ask for a replacement unit. Defective inverter welders are not easy to fix, a DIY-solution is not likely. They are complex machines, crammed with a lot of electronics in a small area. With no documentation, they are difficult to troubleshoot.

To investigate the fault yourself:

- disconnect the machine from the AC supply, wait an hour or two for the capacitors ( with up to 325v DC !! ) to safely discharge, then remove the covers and check for:
- loose push-on spade tags at the back of the main power switch and on the bridge rectifier ( probably a rectangular alloy block mounted on a heatsink, with 4 tags, - there may be two rectifiers in parallel )
- loose bolted connections on heavy internal cables and copper or aluminium busbars, at heatsinks, and on thick tracks on the PCBs, and at the back of the front panel sockets.
- in particular, any loose or poorly-seated plugs on the multi-wire harnesses between the PCBs
- any sign of blackened or burnt components.

** Please be aware that dangerous high voltages are present in inverter welders. DC is more dangerous than AC. Voltages may be present across charged capacitors even after the machine has been powered off and disconnected from the AC supply. Do not work on this machine in a live condition unless you are confident and have the correct equipment.**

Tracing the mains input wires will lead you to the power circuit, possibly via a mains filter. There will be a soft-start circuit ( bypassed by a relay after a delay to allow the large capacitors to charge ), the rectifier(s), and the capacitors. The output of the power circuit will probably be 325v DC, and this will connect to the inverter section, where the multiple MOSFET or IGBT power transistors turn it to high frequency AC. If you are able to do this safely, you can check the 325v DC out of the bridge rectifier and capacitors, which would confirm that the DC power which runs all the machine is basically OK. If so, then the fault is more likely to be in the inverter section, or the control logic that manages it.

 

[D B]

Thanks for the info Eddie, I had a look inside at all connections and circuit boards, and no sign of loose connections or burn marks on the cards. That’s about my limit on inspecting it, wouldn’t have the tools or know how to test across any components. Warranty is well up too, so rules out going back to the supplier. Probably looking at a new caddy. Parweld machine owes me nothing though, great little welder.

 

[eddie49]

Thank you for the update.
If the connections are all OK, then it is likely that one or more of the power semiconductors ( transistors ) has blown up. There's a lot of them, clipped or bolted to the finned aluminium heatsinks and soldered to the boards.
They can be repaired - here's one we fixed earlier:

Parweld XTT182DV no power

I have an XTT182DV inverter set, which is currently not showing any signs of life. A preliminary investigation is showing that I am getting AC voltage to the first pair of rectifiers and when the DC side of the rectifiers is disconnected from the main PCB there is 240V DC. When the DC side of...

www.mig-welding.co.uk

I doubt if any commercial outfit would offer a cost-effective repair, working at component level ( as opposed to just swapping expensive boards ). You could find an electronics-savvy mate to have a go, with help from the Forum, or you could offer it for sale "spares or repairs" - maybe on here.

 

[blobby1]

Hi. you could try the bay, something like this, item 254397605860.

 

[fire hazzard]

Best way to fix this is to replace it with a Rtech or something similar. Parweld is garbage.

 

[JWo]

Hi all!

Looking for some help. A friend of mine asked me to see if I could repair his XTI160DV. A component has blown and I can't identify it. I contacted parweld as the were helpful in the past, sending me schematics and service manuals, but they're not sending me anything helpful this time!

If someone here has the same welder, could you send me the details of the dead component!?

I've attached photos, the culprit is circled! Hard to tell from the photo, but it's popped, only the heatsink is left!
Thanks, Ryan

View attachment 336978

Is this enquiry still alive? I have a very close match to yours XTI-161 DV i need a circuit board for mine but its £50 + so not really cost effective to risk buying it to repair a £150 machine. It may not even be the problem.
It was all working fine but next time I tried to use it it has no obvious fault but there is only a low power spark no decent current. A tiny blown chip on a PCB is the only fault I can find, it is not really possible to read the numbers on it with any certainty, Any one got any ideas?

 

[JWo]

Hi Lads, I have a Parweld inverter that **** itself recently. XTI 161 DV model. I was using it recently, had the machine on while I was prepping & I heard the fan shut off. Then when I went to strike an arc, got nothing, not even a spark. LED light on the power button on the back is still working. I opened the welder up to have a look to see something obvious, no loose connections or burn marks on the cards, so I’m stumped. Any ideas on what might be the issue greatly appreciated. Thanks.

Did you ever get anywhere with this? I have the same machine, and need a PCB. It is available but at £50-60 it is not really worth what is a gamble as it may not even be the faulty part. There is a chip on it which appears to be blown. If you have written yours off maybe I could buy that board from you if you still have it? I can send more details if there is any scope to make progress. Maybe yours is fixed now anyway? Cheers,

 

[eddie49]

Hello, and welcome to the Forum.
I cannot make out which chip on that board is damaged. The semiconductors are all low-power ( apart from what could be a voltage regulator at the centre right ), so they are unlikely to be drawing enough power to self-destruct in a visible way.
It is possible that this PCB is the Control board, which sends gate trigger pulses to the high-power MOSFET or IGBT transistors in the Power section of the inverter. Those devices run on over 300v DC, and are the usual components to fail first. When they blow up they can send high voltages back into the gate control circuits. If you check carefully where the power semiconductors are fastened to the large aluminium heatsinks, you may find signs of damage there. If so, that would mean that there is more than just this small PCB to replace, and so repair would really not be cost-effective.

 

[JWo]

Eddie, thanks for your help, the chip that has blown, (a definite little eruption in the middle) is the one just above the two capacitors in the photo, just above where you can see "C27". It is actually identified as U7 on the schematic but I dont know what it's function is. The big transistors attached to the heat sink look in perfect condition, no sign of scorching or heat. Seems a shame to scrap the machine for such a tiny component but thats the modern world.

 

[ivan 61]

Eddie, thanks for your help, the chip that has blown, (a definite little eruption in the middle) is the one just above the two capacitors in the photo, just above where you can see "C27". It is actually identified as U7 on the schematic but I dont know what it's function is. The big transistors attached to the heat sink look in perfect condition, no sign of scorching or heat. Seems a shame to scrap the machine for such a tiny component but thats the modern world.

Hi U7 is Top 244pn 7pin chip
chip

 

[ndj7919]

Hi, new to forum.. I'm fixing one currently.. it fell over and threw a fan blade. I replaced the fan but now it arc's then shuts down. I have removed the PCB and powered it up separate from machine. One IC was getting rather hot, so I've replaced that. Output is now circa 3A, no tripping.. I've repaired this machine before, fan had gone short circuits so the lights just flashed on front. This is the PSU on the main board shutting down due to fan short. There are 2 CT's, one on the main PCB (which I think is over current) and one cable tied to a post, has 4 wires, 0v, +15, -15 and signal.. I used several turns through the CT from a PSU and it's output looks good. Before the IC replacement I attacked a 1kW 1ohm resistor across output and got about 40A regardless of current setting.. anyway, I really could do with a circuit, this working in the dark is a pain it's.. erm, there are 2 lm324, a tl074, erm, 3525 and a 14066 IC. Forget the 6th IC.. I was working on an idea that the opamps form a pwm signal at 200hz that's used on the pwm p10 to shut the inverter down.. p10 defo changes when you unplug the thermal switch... So far I haven't seen this happening so can't say for sure if this is the way it regulates.. and this is from just falling on its side !!!