If your exhaust fan is not running, then there are other issues.
Unfortunately the control board is set up so that all the components are tied together and work as a team.
If only the room air fan was effected you can wire a controller up to take care of it.
If the exhaust fan is not working too then it gets far more complicated.
The whitfield boards with the control knobs had issues that cropped up as the stove got a few seasons on them
If the feed motor will run on the timer by itself, you can wire the exhaust blower up to run alone but, I am thinking that at this point, you would be far better off to replace the board with a new updated one.
I have designed a complete new control panel for my whitfields but this take a complete rewire of the stove.
If you have some good basic electrical skills, I would be happy to share the schematic.
Now you must keep in mind that once you rewire the thing, all safeties that were in place originally must stay in place to protect you from a hazardous situation.
These pellet stoves are pretty simple.
A draft fan to pull air through the fire pot.
A pellet feed motor
A room air fan to distribute the heat
A one shot timer to start the cycle until the low temp switch closes
A variable timer that allows the feed motor to run about 2 seconds on time and adjustable from 2-8 seconds off time (off time is the heat range control
1 low temp switch
2 high temp switches to protect against a burnback or an overheat situation
A pressure switch to stop the feed in the case of the vent becoming plugged.
I have all the components now to redo my Advantage completely.
The cost for the new timers was $109
The company that the timers came from is Precision timer company
(860) 399-6253
One shot is part number 644B-G5R
Burn timer is part number 646B-P15RO
These units are industrial grade controls.
NOW FYI this setup will require the operator to RUN THE STOVE
You will have far more control avalable than the original board afforded
If you do not feel that you want to try this sort of thing, then a "Plug and Play" replacement board is the way to go.
Here is a link to the post I made regarding a rewire including the schematic.
This Schematic was done for my Prodigy but, the only difference is that the Prodigy uses one fan for the draft inducer/room air.
Simply wire the draft inducer/exhaust to run constant and the room air fan on the speed controller.
https://www.hearth.com/talk/threads/61838/
Hope this helps
Snowy