Miller trailblazer 301g issue

[Scottis1]

Hello all,I just recently perchased a 301G welder, hooked up my leads, go to strike an arc...And nothing. I opened the top panel and took a closer look at everything.I wish I knew how to upload pics but anyway, there is a part that melted on the circuit board.What would cause the PC1 circuit board to fry like that?

[Scottis1]

[duaneb55]

That would be a fried trace (printed circuit). Cause is likely a failed component on the board or a shorted circuit off the board. Can't tell specifics from here.

[Scottis1]

How do you tell the difference?

[cruizer]

Probably some sort of surge, replace the trace with some 22 gage insulated wire soldered point to point and retry it

[duaneb55]

Looks a little more serious than a simple surge to me in viewing the photos. I'd suggest doing a little deeper investigating first but that's just me.

Scottis1, can you post a full view shot or two of the board in an attempt to determine which circuit trace got zapped? It appears to be one of the circuits leading either to or from board transformer T1 as it goes around receptacle RC18 and looks to affect a number of other components along the way.

[Scottis1]

[duaneb55]

Diode D48 has definately shorted likely due to a severe back feed. Unfortunately I don't have a board map to see what circuit D48 is in to be able to offer any suggestions on what to look for as a cause. I recommend a call to Miller Customer Service, Engine Drive Group to discuss the possible/probable cause.

The board can be repaired by replacing D48 and using a small gauge wire as a jumper to replace the burned section(s) of trace.

Below is an example of an Onan generator control board repaired using that method following replacing the failed components.
Onan Emerald III Control Board 005arrows.jpg

After sealant applied.
Onan Emerald III Control Board 018arrows.jpg

[benny]

where can i find parts for pc boards i have a 301g trail blazer that took a back feed and the same thing happen and i am having a hard time finding a print to id the parts i need i have all ready replaced the trace with hard wire but diode #17and fet q7 on the board is there a id parts print out there can you help me please i can not make out the # on the bad parts by the this is pc1

[MichaelMartinez]

It's seem that due to excess of temperature and over heat the Part of the circiut have melted , Don't worry for that getting the part of the Circuit is not at all a big task you can easily get the part in any elctronics Shopee , just make sure which part you want to buy for that you might be needing some elctronics person for that.