You have pin 17 as the speed control, it should be pin 11, also you have no gate drive resistor on pin 4, thats two things wrong.

 

According to TEMIC, pin 17 goes through a 220K ohm resistor and back to L.
According to my diagram, I go through a 390K ohm resistor, back to L (white wire from mains in)

According to TEMIC, pin 4 goes to the gate of the TRIAC through a 180 ohm resistor
According to my diagram, I go straight to the TRIAC with no resistor.

Double checking the board visually confirms both of these findings. Not sure where I am wrong?

 

Keep in mind, I did not make up this board. This is a board that was made for this router and is part of a complete unit.

 

I have to ask again, aren't there any resistor (SMD) types that have gone high ?
Did you check the SMD ones.
If all the resistors are OK there is no way it should not work.

Did you check the SMD caps for short ?

Just put the DVM in diode range and measure the SMD caps that shows low readings.
Without power of course.

 

On the other hand, measure all the caps for shorts.
Please confirm this for me.

 

I like to see a clear picture of motor connected to the controller.
Your picture in unclear of how the wires are.

 

I have checked and rechecked all SMD resistors. As for caps, I have only checked them with a capacitor tester for value and they read OK. Did not check with ESR. Only ones I have not checked are brown SMD's with no marking. Not sure what I am looking for.
As for the picture, there is nothing more to it. It is as shown in my diagram. The picture has a red jumper wire just joining red wire from board to wire in motor. Nothing more to it.

 

What are the two wires coming out of the motor connecting to grey wire of the board.
What are those two wires....{ed}⇒Is it Neutral ???

The brown SMD's do get shorted. Just check for really low resistance across the brown SMD caps.
If low it is a problem.

Another thought.
take out the resistor that connects the center of triac to the pin 1 of IC. Check if the values has gone high or not.
If it is high than rated, could be a problem

 

The two wires coming out of the motor are from the field coils I believe. One goes to purple wire on board (grey) and the other goes to pink wire on board.
the resistor coming off the TRIAC was replaced because of low value. Checking SMD caps now

 

I have gone through and checked all the SMD resistors again. All read as they should. Checked SMD caps as per your instructions. Nothing to be found.I think I'm toast for the day. My head hurts

Just a quick thought. The 22uF caps in parallel connecting pin 2, 3 and 5. On pin 5 is automatic retriggering. Could they affect this if they were shorted or open? How can I check electrolytics?

 

the resistor coming off the TRIAC was replaced because of low value. Checking SMD caps now

Wait a minute.
Can you confirm the value of the original & what you replaced it with.

 

The original from the TRIAC was a 390k Ohm resistor. It measured okay but looked like it may have been damaged. I replaced it with the same.
The other one I replaced was the 22k Ohm resistor. The original was red,red, orange and measured 92 ohms.

 

So how far have you got,is it working?

 

The other one I replaced was the 22k Ohm resistor. The original was red,red, orange and measured 92 ohms.

can you point this one out from image.

 

can you point this one out from image.

In post #11, it is the one beside the speed controller. Dodgy, it sits on my bench right now and unless the electrical Gods smile down upon me and deliver an answer that I know will fix it, I'm not touching that thing again. I knwo I said I wouldn't give up, but for the moment, I'm stumped. Doesn't help that I don't know how the circuit should work but I've tried everything othere than changing the electrolytics and surface mount components and if it comes to that point, it's too much work for the end game.
I was hoping this would be simple but I guess not.

 

In post #11, it is the one beside the speed controller.

If it is the one connecting from Neutral to a 820Ω SMD to pin#8 of IC, I do not think it is a 22KΩ. Can you measure the bad one or how put that one back and check the controller.

 

In my opinion, you'd better get the highest rated cap in that same footprint. It is the best way I think.

If the OP is correct with 1.5uF - its probably possible to get a multilayer ceramic chip that will fit.

Much more hardy component, and won't go leaky at the tinyest hint of reverse voltage.

 

Looking at your drawing ,you have two 100k resistors from pin 18 ,doing nothing!! also i think the live and neutral should be swapped, but that wont fix it,

Why dont you use a light dimmer instead, rated at 500W, if it works just put a bigger Triac in.

 

1) The original resistor was red, red, orange and measured 95 Ohms.
2) My bad. I said use drawing from Post #29. I had it numbered wrong. Use drawing in post #35. I had numbered the IC wrong. What you are looking at as pin 10, is actually pin 18. Now I see what you meant by my drawing was wrong. It was corrected but I led you to the wrong one. Sorry about that. Post #35
3) I asked about the live and the neutral a long time ago and nobody seemed curious so I figured it must be okay. It never looked right to me. I live in Canada. Black is hot, white is neutral. They are connected opposite to the diagram.

 

so your pin 8 has a 22k, and a 820 ohm in series to ground pin 2., no tachometer then...