mikeeyre74 289 #1 Posted March 8, 2018 second time now. That damned circuit board keeps going up in smoke. That was my last spare board... is there any reason why I “need“ any of that crap in the LED circuit board? Share this post Link to post Share on other sites
WHX?? 50,704 #2 Posted March 8, 2018 (edited) Yikes! Any chance water from blowing duty getting in through a bad connector and causing a short? Maybe a (intermittent ?) short of some kind exterior to the board that is causing it to fry but why not blow a fuse first? Engine temp on while blowing snow ?? A clue perhaps. Disection of board may reveal a clue also. Edited March 8, 2018 by WHX14 Share this post Link to post Share on other sites
mikeeyre74 289 #3 Posted March 8, 2018 This literally just happened, and I have to hit the sack now for work tomorrow so I will inspect this later, but the first one just melted down one of the LED lights on the right-hand side of the board, And that killed it. This one did pretty much exactly the same thing, with the engine temperature light starting to flicker just as I saw smoke starting to come out of it. Share this post Link to post Share on other sites
shallowwatersailor 3,214 #4 Posted March 8, 2018 I would first check your grounds, and clean them. It sounds like it may be taking a path through the board. 1 Share this post Link to post Share on other sites
mikeeyre74 289 #5 Posted March 8, 2018 When the original board burned out, I took the dashboard apart and cleaned all the contacts. I also replaced the battery and cleaned the main cables all up as well. What else am I missing? Share this post Link to post Share on other sites
lynnmor 7,557 #6 Posted March 8, 2018 1 hour ago, shallowwatersailor said: I would first check your grounds, and clean them. It sounds like it may be taking a path through the board. That would be my guess. You likely have a bad connection somewhere and not necessarily near the board. Share this post Link to post Share on other sites
cleat 7,023 #7 Posted March 8, 2018 Has the harness been butchered in ant way anywhere ? Just wondering if a signal to the board that is supposed to ground is instead being supplied with 12V or vice versa. Signal could be from any of the LED indications displayed on the board. For example Parking brake signal is +12V when disengaged and open circuit when engaged to operate that particular LED, if that signal gets inadvertently grounded then board could get damaged. Engine Temp is grounded to turn on LED. If +12V is inadvertently applied then board could get damaged. I have enclosed the wire diagram for your machine which outlines every circuit to your display board and you can follow each wire to determine the proper signal supplied. Later model 520 wire diagram.pdf This may take a bit of time but in the end should solve your problem. Cleat Share this post Link to post Share on other sites
mikeeyre74 289 #8 Posted March 8, 2018 (edited) In the meantime, while I try and source another one of these boards for the LED's, if I just unplug the board, will that be sufficient to keep things running without fires? These boards aren't all that cheap and I'm not sureI'm gonna be able to finding, even.. To answer your question, yes, the harness was modified. The P.O. had the Molex connector removed after it melted down and everything was soldered directly, without connectors. It appears to be well done, with heat shrink tubing on all wires. They did not bother to install the lights in the dashboard though, and none of them work or are even installed in the sockets. A couple of the gauges were missing as well. Edited March 8, 2018 by mikeeyre74 Share this post Link to post Share on other sites
cleat 7,023 #9 Posted March 8, 2018 You can run without the LED board. My 520HC only just has one LED for low oil pressure. Cleat Share this post Link to post Share on other sites
pfrederi 18,325 #10 Posted March 8, 2018 No 520s in my herd (and don't anticipate getting one just because of the electrical issues that routinely seem to pop up) Did Toro subcontract the electrical work on 520s to Lucas Electric?? (aka The prince of Darkness) 1 Share this post Link to post Share on other sites
squonk 42,519 #11 Posted March 8, 2018 31 minutes ago, pfrederi said: No 520s in my herd (and don't anticipate getting one just because of the electrical issues that routinely seem to pop up) Did Toro subcontract the electrical work on 520s to Lucas Electric?? (aka The prince of Darkness) Share this post Link to post Share on other sites
pfrederi 18,325 #12 Posted March 8, 2018 6 minutes ago, squonk said: Absolutely Fabulous and sadly true Share this post Link to post Share on other sites
cleat 7,023 #13 Posted March 8, 2018 44 minutes ago, pfrederi said: No 520s in my herd (and don't anticipate getting one just because of the electrical issues that routinely seem to pop up) Did Toro subcontract the electrical work on 520s to Lucas Electric?? (aka The prince of Darkness) The only real electrical issues I have are mainly left to me by previous owners. Once I repair, clean and grease up the connections then I have no more issues. I do not leave a machine outside ever and that helps a lot as well. Cleat Share this post Link to post Share on other sites
