Sundance Sentry 800 help

My friend has non-functional Sentry 800. On the board the resistors R26 and R28 are burned out.
Probably the triac TH2 (MAC 223 A10) also burned. Not sure about Diac U23 (MOC 3021) and transistors.
Questions:
Where is possible to find schematic?;
What could cause those problems? (Motor shortage?);
What triac could replace MAC 223 A10 ? I can't find exact that. May be it is obsolete.
What are values of resistors R26 and R28? They are burned out and black.
Any help will be appreciated.

Sorry ING,

Cant find any info on control circuit diagrams / schematics, but found you some datasheets on the triac plus a possible equivalent from Mouser.
The closest equivalent from Mouser is a NTE56018 see attached pdf datasheets.

hope this helps (a little)
Rotarymaker