LT40HD Feed Rate Circuit Board Repair or Replace

[Mountain_d]

My LT40 HD feeds forward at full speed no matter where the feed rate dial is set. I spoke with Woodmizer tech and he is confident it is the circuit board. My board was replaced around 2010 (previous owner) but is still a one piece board with no LED lights on it. I can replace the board for about $620.00 Can. Anyone ever try take this board to someone to troubleshoot and solder in and replace board components? I could likely find someone that could do the work but could they do it without a schematic of the board? Would anyone have access to the schematic (board part number P20420 B)? Based on members experience, anything else could cause a runaway feed rate? Do you think I should just bite the bullet and get the new circuit board? 
Thanks in advance for any help.
Mountain D. 

[Southside]

I don't know if they could help you or not, but dinosaurelectronics.com has fixed a couple of A/C boards for me.  Worth asking, they are good folks.  

[SawyerTed]

Has the dial/potentiometer been eliminated as a possible bad component?  It should be easy to test.  I like to start simple and work up to the complex. It's less expensive that way. 

[KirkD]

Ted is right check that first. I don't know if your 95 is the same as my 89 but mine has a box that is nothing but a motor speed control and a forward/ reverse switch to start the feed the direction you want it and that is it.
I had the motor speed control board go out on my Woodmizer drag sharpener and replaced the whole board with this https://www.amazon.com/gp/product/B071NQ5G71/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
I was able to mount it inside the same box the old board was in. Not sure if 30 amp is enough for the motor on the feed but there are a lot of other DC speed controllers out there and doubt you will need to spend more than $100 for one that will work.
Hope this helps someone ;)

[Chuck White]

With a schematic diagram of the board, any competent electronics technician should be able to trace the circuits on the board to a defective component, then just match up the component and a simple remove and replace!  ;)

[Mountain_d]

I bought a cheap circuit board from eBay for about $70 Canadian. It works. I cut about 400 Bd ft with it so far. So far, so good. The proper board from WM would have been $620 Canadian plus tax. The board I bought was listed as a "100a 5000w Reversible DC Motor Speed Controller PWM Control Soft Start". 
Mountain.