Blackline Mig 200 help please.

[Tin Chicken]

Hi, I'm new to the forum so hi everyone
I have a mig 200 as I'm building a hot rod in my garage and I have to say, it's a cracking machine. However, I turned it on yesterday and no power!
I stripped it down after testing feeds etc and found 240 V going into what I believe to be the bridge rectifier and nothing coming out.
Has anyone else had this issue and if so how did you get around it or were can I get this spare part ?
Thanks in advance for any help given .
Nige.

 

[Hutcho]

If you can see the part number - google it and see what turns up

 

[eddie49]

Hello and welcome!

Is your BlackLine MIG-200 new? If so, it will be under warranty, and you should contact the supplier to ask them to repair or replace it.
I think the warranty is for 1 year. If this has expired and you want to continue investigating the fault yourself, please be aware that there are dangerous voltages present in inverter welders. The 230v AC mains is usually fed via a double-pole On/Off switch on the rear panel to the two AC input terminals of the bridge rectifier. Your photos show that there are two rectifiers in parallel. The DC output from the rectifiers is fed to large smoothing capacitors, and these may hold the hazardous 325 volts DC for some time even after power-off. The terminal at the diagonally-trimmed corner of each rectifier is the positive output. This DC bus is fed to the power stage of the inverter, where switching semiconductors ( MOSFETs or IGBTs ) convert it to AC at 20 to 100 kiloHertz.
Usually the connections mentioned ( mains cable, switch, rectifier in & out ) are made with push-on tags. These are often poorly fitted or weak, so check all of the tags. If you are confident working on live high voltages, disconnect the output cable at the positive of the rectifiers, and test again for 325v DC between the negative and this positive pin.

 

[Robert Weaver]

Id try warranty first.
The voltages on that photographed part should be ac 230v on pins cp1 and 2, and full wave rectified on cp3 and 4. If the remainder of the board is attached, the caps will smooth the bolts to DC 315v, if not then you'll have a lumpy 100hz signal which you're multimeter may not see.

 

[Tin Chicken]

Thank you for your advice, unfortunately it is out of warranty so no joy there.
I did check cp1 and cp2 and had full voltage Inc a 240V two pin output on the back of the case.
I did try cp3 and cp4 but on AC not DC reading and had no output however, at the time I did not know this was a DC output so I will connect up and retest.
Nothing on the machine works other than the light on the on/ off switch on the rear of the machine.

 

[Robert Weaver]

The switch will be self illuminating, with no input from the parts after it.

 

[JOEPRO]

Email blackline with photos of the part and ask to buy a new one. I'm sure it's not that expensive.

I bought a couple of new boards for my SIP AC DC Tig and in the grand scheme of things they were inexpensive. I would just look for new parts and save yourself hassle.

 

[Tin Chicken]

So on the DC output from the board is only 9V so I'll probably email Rally Design as they are the UK distributor and see if they can supply a new unit.
Thanks for your advice and help

 

[Robert Weaver]

If there's no joy with rally design, and it's that part that's failed,the rectifiers can be replaced...
https://www.ebay.co.uk/itm/15578371...MtL0Gz0Sna&var=&widget_ver=artemis&media=COPY
(Or similar)

 

[Tin Chicken]

If there's no joy with rally design, and it's that part that's failed,the rectifiers can be replaced...
https://www.ebay.co.uk/itm/15578371...MtL0Gz0Sna&var=&widget_ver=artemis&media=COPY
(Or similar)

Hi Robert, your a star mate. I thought they may come off the PCB but didn't want to try too hard.
Now I know they do it makes sense.
Two on order and I'll let you know if it fixes the issue.
Thanks again for your help.
Nige

 

[eddie49]

It is odd that two high-power rectifiers in parallel have both failed and appear to be more-or-less open-circuit, with only 9v DC output.... Was that measured off-load, i.e. just this small connector board with the two rectifiers, 230v AC mains in on CP1 and CP2, and a meter set to DC across CP3 and CP4 ( positive lead on CP3, negative lead on CP4 ) with no connections onwards to the rest of the inverter ?

The two bridge rectifiers on that small connector board are the modern generic type, with a diagonally-cut corner to indicate the Positive output pin. That pin is also turned at 90 degrees with respect to all the other pins.
The "old stock" rectifiers in the link above do not have this layout so will not fit into the board easily.

In addition, these International Rectifier "IR 26MB20" components are incorrectly described in that eBay listing.
The datasheet:

26MB PDF

Part #: 26MB. Description: SINGLE PHASE BRIDGE. File Size: 46.91 Kbytes. Manufacturer: International Rectifier.

pdf1.alldatasheet.com

shows that they are rated at 25 Amps not 20 ( so two in parallel would be OK ), but the "20" is in fact the voltage code, and at only 200v that is not high enough for use on AC mains. Normally 600 or 800 volts is specified.
I would suggest searching eBay for "25 Amp 1000v rectifier".
Such as this UK supplier:

Pardon our interruption...

 

[Tin Chicken]

Just an update, Eddie 49, I took your advice and ordered correct bridge rectifier and fitted them back onto the welder.
I now have 320 ish volts DC output from the board but everything else is dead so it looks like I'll have to find a welder repair shop and let them have a look.
I'm not experienced in welder electrics so better to let the experts take over.
Thanks all for your advice and help.

 

[eddie49]

When inverter welders fail, it is typically one or more of the power transistors that "invert" the 320-ish volts DC ( i.e. turn it to high-frequency AC ) that go short-circuit. This usually blows the 13A fuse or trips the supply breaker. It looks like in your case this overload blew both the bridge rectifiers open-circuit.
Due to the complexity and lack of documentation, not many places will repair imported hobby-level MIG welders. You could ask Rally Design Ltd. if they know of out-of-warranty repairers for their welder.
Tec-Arc in York do repair inverter welders:

Technical Arc

The UK's leading manufacturer of welding & cutting equipment.

technicalarc.co.uk

 

[Tin Chicken]

When inverter welders fail, it is typically one or more of the power transistors that "invert" the 320-ish volts DC ( i.e. turn it to high-frequency AC ) that go short-circuit. This usually blows the 13A fuse or trips the supply breaker. It looks like in your case this overload blew both the bridge rectifiers open-circuit.
Due to the complexity and lack of documentation, not many places will repair imported hobby-level MIG welders. You could ask Rally Design Ltd. if they know of out-of-warranty repairers for their welder.
Tec-Arc in York do repair inverter welders:

Technical Arc

The UK's leading manufacturer of welding & cutting equipment.

technicalarc.co.uk

Thanks for the information. I've had to bit the bullet and brought a Headux titan mig 195. So I'll have a look back at the 200 when I've got time or sell it for spares if anyone wants it.
Thanks again for all your help

 

[eddie49]

brought a Headux titan mig 195

Heard about that brand for the first time recently:

Headux TitanMig 218ixp

Hi, does anyone have experience of this welder that they can share ..... https://www.headux.com/TitanMIG-218XP.html Cheers

www.mig-welding.co.uk

Looks like "Headux" might be quite an impressive company.