With the cheapest multimeters costing as little as just a few dollars there is no reason not to have the ability to check things instead of guessing.
With most portable tools and appliances the first thing to check is the power cord because around 60% of the time an internal break is the cause of a tool not starting.
Power tools and appliances often have electronics to provide variable speed or soft start. Checking these is beyond the scope of the home repairer but a multimeter can check continuity to any electronic component and from it to the motor and the ensure there is continuity through the motor.
If everything else is ok the fault is probably with the electronics if there is any. If you are feeling really brave, the final test is to temporarily and safely bypass the suspected component and apply power.
you can use a portable bandsaw to cut rebar, I find it to be the best solution when I can't take the rebar somewhere to cut it. But be careful if the metal is heavy it could fall and dent/damage the floor if you're working indoors of cause injury should it land on you.
Use a third blade, preferable mounted to your utility handle, to part them. Handle only from the back side and give the utility knife a slight twist as soon as it is between the points of the new blades.
Manual bolt cutters usually have symmetrical V-edge cutting blades. With the sharpening angle in the range of 20-30 degrees. For comparison, the sharpening angle of the kitchen knife is less than 10 degrees. With such a pretty blunt edge is impossible to cut your finger. But this is the best option for cutting thick metal rods or cables. Like this:If it is interesting to read more information about bolt cutters, I recommend this review - https://toolslaboratory.com/best-bolt-cutter-buyers-guide-2019
This utility knife reassemblies similar to the original. The only difference is this model uses two screws and that plastic insert. You will align the two metal halves and bring them together. Use care that the blade does not fall out of its holder and the little black plastic piece stays in place, near the blade. This may take a few tries. after you bring the two halves together you will carefully separate the bottom end (farthest from blade). Separate it just enough to slide the plastic insert into position. Once the three pieces align you will know. With little effort the two metal halves will close together. Install the two set screws and test for proper function. I'm including a Youtube video that shows how to properly change the blade and what it will look like after it is reassembled.
https://www.youtube.com/watch?v=5napTSRSyeQ
the utility of a utility knife is far more than most people expect. That is why, everybody should have the best utility knife as a companion to their daily Do-It-Yourself activities. More details BEST UTILITY KNIFE TO BUY FOR DAILY USES
Slicers stay wet from use and constant cleaning (hopefully) in delis and butcher shops. Parts can get rusty, especially one made from aluminum or stainless steel from that era. Soak the offending parts with penetrating oil over night and tap with a mill hammer or other non metallic hammer. Applying some heat with a Wagner heat gun may help loosen things up.
I used a Dremel with a diamond cutting wheel. First draw the oval shape you want in a window marking pen available from newsagents or post office, so you can rub it off easily. Then slowly cut around the edges, you will end up having to do small straight cuts keeping as close to the line as possible and then just file or sand the small edges that are left. Make sure you wear protective eye goggles and i would recommend a mask of some sort so as not to breath in the glass dust. Good luck.
"A glass cutter is a tool used to make a shallow score in one surface of a piece of glass that is to be broken in two pieces. The scoring makes a split in the surface of the glass which encourages the glass to break along the score." (Wikipedia)
With the sharpening angle in the range of 20-30 degrees. 
For comparison, the sharpening angle of the kitchen knife is less than 10 degrees. With such a pretty blunt edge is impossible to cut your finger. But this is the best option for cutting thick metal rods or cables. Like this:
If it is interesting to read more information about bolt cutters, I recommend this review - https://toolslaboratory.com/best-bolt-cutter-buyers-guide-2019
