Cybex 530t Pro+ DC Control Board Problems

Thread Starter


Joined Dec 23, 2013
Okay, so I found this site while searching endlessly on Google for help on repairing this damn thing! I actually graduated with a BS in Electronics Engineering but never used it and actually went into the computer field. Anyhow I got burned buying my treadmill off of CL after my handed down Precor (20+ years old... great product) finally gave out. So the couple that sold it to me "seemed" VERY friendly and like genuinely kind folks. Purchased it from there home and was told that the reason it wouldn't go full speed was because they didn't have the proper power. It was an older home and because I know that my Precor needed a 20Amp circuit and kept blowing the standard 15Amp outlets which are mostly in my home... it made sense to my stupid mind! I get social anxiety too... another story.

Anyway when I got it home, as is my nature, I completely broke the thing down for two reasons. #1, as I said it's in my nature... to completely clean stuff I buy from other people and I mean CLEAN. There seemed to be a mouse issue somewhere in the lifetime of the treadmill because I found a fair amount of droppings on the hidden parts of the treadmill (side walking deck support, circuit board, etc). So I disassembled it which was rather simple after all it is just a treadmill. Washed everything with pine sol, bleach, elbow grease... the thing is practically new now. Oh, and #2 because the damn thing was very heavy and it took two grown men to get it on the trailer, alas it was only me when I got home and needed to get it off the trailer AND up the stairs to it's final destination.

So after cleaning, transporting, and reassembly I fire the thing up and it throws an error code but it's just because the speed sensor needs adjusting, so I do that. Try again and the belt will not get up to top speed which is 12.4mph. The motor tops out at about 7.0 and whenever I step on the belt it bogs down terribly. Performance is frighteningly like that of when I walked on it at the couples home and was told the reason was due to the power outlet it was plugged into. Anyway, I've ruled out the motor as being faulty as I had a known working one to swap it out with and same symptoms. Further the brushes on the motor are fine, and the magnets also seem okay. Upper control boards are the cleanest thing on the treadmill and they seem fine. Connections to everything are good as well as the wiring. Considering the mouse fecal matter previously on the board and the suspect physical condition of the board amongst all that's already been explained... my guess is that I need a new DC control board. A quick search on Ebay, et al showed that I was going to be out another $250 for that part! Now a reminder... I went to school for this stuff so I do have the ability to big picture things. The big picture here is that a few components which might amount to a few bucks is/was going to cost me an additional $250 on top of what I already paid for the damn treadmill in dollars... not to mention time and effort. WTF?! Which brings me here. I'm hoping someone can shed some light on this damn circuit, what it does (it's really been that long), testing methods, suggestions, … guesses. It's been 4 weeks (going on 5 now that my previous treadmill broke and my body is suffering greatly). I really NEED to get this thing working.

I've attached detailed photos of the DC control board. Let's get this started.



Joined Apr 11, 2010
The pictures are so large, they cannot load in my browser and leave the post legible. Perhaps attach them via a zip file and insert smaller versions in your post.


Joined Feb 5, 2010
In the first two pics, I see two traces and possibly others that have carried far too large a current. They are crinkled and corroded now that the conformal layer has been cooked off by high heat.

Look between the white connector plugs and the two wax fixed variable pots.

Evidence of damage is clear to me. most likely the section controlling current to the motors is faulty and has failed in a way which is limiting current, hence the low power condition of the treadmill.

I don't have time to hold your hand and direct you with meter readings and possible avenues of investigation. Perhaps another member with more time to spare at this busy time of year can assist you further.

Thread Starter


Joined Dec 23, 2013
Kermit2, MUCH THANKS!!! More than anything it helps to have additional heads so to speak. I haven't looked at enough circuits to even be sure enough to make the conclusions you have... although the traces did appear suspect... I just wasn't sure/confident at all in my assumptions. In this case it would seem to me that the only course of action would be board replacement?


Joined Aug 27, 2018
G'day mate!

I'm looking at modifying this circuit and motor to run a power hammer I'm building in my workshop here in Australia. My partner very thoughtfully dismantled it to make room in the shed, but didn't take a photo of the connections on the board first, so now I need to find where I'm supposed to plug it all back in.

Have you by any chance got a photo of all the wiring hooked up in the right locations on the board? As in a "which colour goes where image"?

I'll be adapting a resistance pot to replace the digital treadmill control so I can have a "speed" dial. Hopefully I'll be able to run a few different projects similarly in the future if I can work this one out!