LN 25 Pro Troubleshooting

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I recently stumbled upon a 2010 Lincoln LN 25 Pro at auction. Upon inspection and initial testing it is doa. After disassembly and further inspection found the diode bridge fried, the power supply wire from input to diode cut out and missing, the work lead disconnected from diode bridge. From all my inspecting and testing I am finding all the problems seem to be right at the diode. I am going to replace it as it has visible damage. Also tested with multimeter and it is open shorted to the negative side of bridge. The question I have is there anything else that could be wrong or have caused this issue? And, would this cause it to not power up at all? Any help from anyone with knowledge on this would be helpful.
Reply:The bridge rectifier is used as a auto polarity device. No matter how the LN 25 is connected to a welder the correct polarity voltage is applied to the flexpower control pcb. Depending on which version you have. power goes from the rectifier through a filter then to the control pcb. The first ones had only a coil. Then they moved the coil to a filter pcb and added more parts. It is mounted just above the control pcb.If you are lucky only the rectifier failed. You will have to replace it and then apply power and see if it works. There is an LED on the control pcb that has to light up before it will work. Also the little fan will turn on. If the 5vdc power supply is good.You will need to apply more than 15vdc and less than 100vdc for LN25 to work.Haven't seen to many rectifiers blow. replaced a lot of filter pcbs and a few control pcbs. If you need a owners manual go to Lincoln's web site and under the resources tab, select parts. it will take you to the service navigator. enter as a guest. then put your code number in the box. wait for LN25 to appear then select it. Should have a machine diagram you can get.
Reply:Thank you that is some great information. I do have the Filter pcb in mine. I also have the owners manual, that is how I traced out the missing wires. I was looking for more technical information, such as what you just gave me. even if I have to replace all the boards in this thing I am still safely under retail on price. At least parts are still available.