By your post you've had your new-to-you Tesoro for about 1½ months so maybe you've had several opportunities to get out and put in some hunt time with it. My two all-time favorite Tesoro's, the Bandido II
microMAX and Silver Sabre
microMAX, are always welcome in my travels. Either one of them or both are kept in my vehicle to join the others I decide to take with me anywhere I go.
I have two of each, and all four of them have a like-new, pristine appearance, and that's how I like to maintain all my detectors.

I'm curious which search coil(s) you prefer to use on them and the sites you tend to grab them to put to work? I have two of the standard 8" brown Concentric coils on their 'standard' metal lower rods that I keep in my accessory coil tote, but all four of my devices have the non-metal lower rods and each has their own 6" Concentric coils attached. That's the combination that seems to have been working best
for me in all the sites where a Tesoro gets called into action.
It's sad the company failed to hang in there, but most of their detectors hold up well when treated kindly, and they can continue to perform well and should long into the future. I had a late start today and it heated up too quickly, but my Bandido II µMAX will likely be the first-to-grab unit in my travels when I had out later this afternoon/evening as it starts to cool and also tomorrow as I will be out at crack-of-light.
(I sure wish I could handle the hot days of summer like I could when I was younger.)
Let us know how your unit is handling things for you.
Monte
"Your EYES ... the only 100% accurate form of Discrimination!"
Stinkwater Wells Trading Post
Metal Detector Evaluations and Product Reviews monte@ahrps.org ... or ... monte@stinkwaterwells.com 503-481-8147Detector Outfit: A selection of my favorite makes and models, with the best coils mounted, for the tasks I'll take on.Pinpointers: Pulse-Dive & ProPointer AT .. Headphones: 'Hornet' & 'Wasp' .. MS-3 Z-Lynk .. ML-80 .. N/M Green edition*** All working well today to make memories for tomorrow. ***