A blast of compressed air sometimes works wonders.
Ah the old DW735. I just did some heart surgery on my old planer. I always check the roller speed rate gear(photo 2 on left) that operates outside the planer with a toggle switch that tells you normal rate and finish rate speed. This is something you change ONLY while it is running. Strange.
If you are like me, I don't switch it very often and I don't recall that it made a difference if you take a light cut. This is the loudest machine in my shop and taking a healthy cut on some sugar maple makes that thing scream.
Back to the switch. Along the pathway to the motor from the red pull / push switch is an interrupter safety switch. When the owner puts the
lid on the machine the on/off switch will work. There is a visible detent hole that you can wedge a piece of wood in to make the line hot again.
For those repair nuts like me I wedge a small piece of wood in the detent opening so I can see what is happening. I know this sounds reckless but at the time that I did this I was searching for where the dust chips were coming from that filled up the chamber, made the adjustment posts clog and yes sir MADE THE CONTACT POINTS ON THE ON/OFF SWITCH WORK IMPROPERLY.
There was so much dust and wood chips in the chamber the switch did not work correctly.
I would do the following:
1. unplug the little beast.
2. remove the 4 cover screws and lift it off.
3. From the inside just a simple look around the back of the switch area. If there happens to be chips all around the contacts, this might be your solution. Clean it up.
If there are tons of wood chips in the chamber-- you most likely have a crack some place in your impeller cover.
I would trouble shoot the switch. I hesitate to suggest doing what I do but you'll need to get a look when its operating.
If the worst pans out and you need a switch, I have had good luck with Eplacement supplies.
good luck