Help with '57 National Acoustic w/ Gibson Body

[walkindaddy]

i have little experience with working with acoustic guitars. I would appreciate your direction to a problem, which you may have the solution for in acoustic guitar 101...

A friend passed to me his 1957 National Acoustic Guitar. Valco Model 1155E, it appears that Gibson/Kalamazoo provided the finished j-45 bodies, assembled with a national neck....

their is a neck pickup built into the last fret, with six screws exposed
(thru the rosewood fretboard) for adjustment. unfortunately, it doesn't work though...

i replaced the one tone and one volume pot factory installed on the upper bout. i used new a250k pots on both.

i can tap the pup with a screwdriver tip, and it thuds out to the amp,

however no music through the amp when i strum it.

am i using the wrong acoustic bronze strings?...it doesn't appear to have a preamp/battery option built in.

i appreciate your consideration with helping me

[jonfields45]

Do the controls, relative to the screw driver test, change the volume and tone as expected?

Could you post a picture of the pickup?

Do you have access to the back side of the pole pieces?

One possibility is the pickup's magnets became demagnetized at some point. While this is not likely the cheapest option, you could try placing a magnet at the back side of the pole pieces:

https://www.stewmac.com/Pickups_and_...ar_Magnet.html

Another possibility is the tone control capacitor is shorted.

[walkindaddy]

thank you for your assistance.
re:

yes the volume and tone change when doing the screwdriver test

yes i have access to back of the pickups, i did not want to get "under the hood" because i don't know what i am doing... (strats and les pauls are no problems for wiring with me)

i could recheck/replace the tone capacitor on the tone knob if needed.

again thank you...

[jonfields45]

I would try putting a household magnet on or next to a few of the pole pieces and see if those strings start to be picked up. If that helps, then you can research an appropriate inexpensive bar magnet intended for pickups. The Stew Mac Alnico one I posted above seems kind of expensive and then there is the shipping.