This is Memo's reply today. "The Tribute truss rod nut uses a 4mm hex wrench, here is the link for the nut used on Tribute instruments
https://g-l-online-store.myshopify.com/ ... bullet-kitAs for the bridge pickup not working in the series parallel mode; check the bridge pickup connections to ensure the wires are connected properly also look for wires that may be shorting out with other solder points as this will cause the pickup to become intermittent. I have attached a copy of L2000 wiring diagram so you can check to make sure everything is wired correctly. If you have any questions email me back, have a great day."
After I read his reply I checked the (Harbor Freight) hex wrench set I used and I did use a 4 mm wrench and not a 5 mm that I listed prior.
The second part of his answer is toward another issue this bass has that I asked him about. The following was my question to him "Other issue is the bridge pickup works fine in every combination except when the parallel/series switch is set to bass boost. In that mode it's barely audible. The neck pickup works in every mode/combination. Both pickups engaged work in every mode/combination.
I checked wiring and none are disconnected. Solder joints look okay, but may not be.
Tapping on the pickups with a chopstick produces sound. Seems to be getting 11 out of the 12 sound combinations. Any thoughts?"
He attached an L2000/L25000 wiring diagram in his e-mail. I tried to attach it here, but not sure how to do it. Very kind of him to reply so quickly to me.