I borrowed evo treadmill 500i, but dont have the safety key for it is there any way of starting it? i have no idea where the key is to be inserted either.

do you have the safety key clip inserted into the console ?
http://www.amazon.com/Safety-Key-Proform-Weslo-Treadmills/dp/B006E7YTIC

http://www.fitnessrepairparts.com/equipment/Select/15953/Proform/PFTL700090-705-Trainer

Contact the store where you bought it. I'm sure your treadmill is covered by the warranty.

Anyway, the next time buy some high quality treadmill to avoid any hassle. I like the treadmills reviewed here: http://www.your-workout-routine.com/cardio/best-treadmills-2014/

no fold up a card the size of the key and insert...it worked for me.

Error Code: Replace Safety Key (SAFE)
Meaning: Safety key is not recognize
Diagnostic: Replace safety key
If problem persist replace upper display board
you should also try cleaning the area where you insert the key magnetic

horizon rct 7.6 , safety key off , replaced ,key.reed switch and board , still says safety key off ?? spoke to horizon several times and repair techs as well ,it can only be 1 of those 3 items , all switch & key tested good , must be a faulty new board ?? could it be anything else ??

I have a Weslo Candence treadmill and I too lost my safetly key and I recently folded up a leftover valentine's card from my child's kit box and to my surprise it worked. I just folded to the size of the key and inserted and the treadmill started up with no problem. YEAH!

We have no idea, but it is now working.

I pulled the safety switch out, and the elevation is stuck on 10 degrees

Try putting the treadmil in a cooler location. the heat is effecting the mother board.