Help with SS Checkmate 12 (CM12)Teisco amp

[Teisco_Kid]

Hello all'
well somewhat proficent at self-taught guitar repairs ..
can solder well read a meter had 6 months electronics in 70s
know diode capacitor resister transformer understand voltage
wire houses 100/200 amp NP..
will never make a buck on guitars but derive satisfaction and spend untold hours gaining experiance and learning ..its a hobby on steroids for me ..
OK so I bought a beat up amp for parts ..(another project for another day)stuff
but have no idea about powered speakers..used to car systems..
Teisco Checkmate Solid State amp/prefer to fix instead of cannibilizing
very loud humming and speaker vibrates like hell
turn up volume tone changes a bit but still loud/would say pitch changes maybe ?.. ..tone pot makes little difference ..
checked well visually for damage ..
believe all original never had repairs
Damage or what I think could be wrong is missing solder on circuit board
appears maybe it fell off ..solder applied to copper foil ? on printed circuit board ..2 spots..
I jumped these with power on carefully no change in sound same hum ..
I read somewhere about speaker and a coil or transformer like power supply attached to magnet thereabouts ..shellac comes off ..need to re-dip it..
all wires appear good see no components fried so looks like I have to test and need a starting point..
have lots time and willing to try repairs..
I do not have values for components but may have a schematic on-line I saw..
have checkmate 10 amp SS schematic but newer smaller ..
probably only good for identifying similiar values..
Anyone up for this ?
Or maybe easy fix for a pro ? I leave it alone ?
sold my scope years ago , thought never would need again..go figure ..
but have a real expensive telephone meter box for communication work
not sure how to use it though ..high end meter of sorts
not sure if any good for this type work anyway ..
well see what happens ..my 1st post about amps ..
posted problem areas I think need advice on ..proper acid core solder ect
Thank you kindly..
Teisco_Kid