AstroAI Digital Multimeter Tester
“Non-negotiable for charger teardowns. I always check voltage before touching anything inside a power supply — this has saved me more than once.”
— Object Opened
The AstroAI AM33D is a 2000-count digital multimeter that measures AC/DC voltage, DC current, resistance, continuity, and diodes. Double-fuse anti-burn protection and a silicone protective cover make it safe for beginners and pros alike. Batteries and test leads included — ready to use out of the box.
- Measures AC/DC voltage, DC current, resistance, continuity, and diodes
- 2000 counts with backlit LCD display
- Double-fuse anti-burn overload protection
- Data hold, auto shutoff, and continuity buzzer
When to use it
Before opening any power electronics (chargers, power supplies, inverters). Always verify capacitors are discharged to safe voltage levels before touching anything inside.
What it replaces
A basic continuity tester can check some things, but a multimeter gives you the full picture. Don't skip this for power electronics.
Frequently asked questions
Yes. Every tool listed on this site is one we actively use in Object Opened teardowns. We don't list tools we haven't personally tested.
No. Start with a precision screwdriver kit, a spudger, and opening picks. That covers most phone and small device teardowns. Add specialized tools as your projects demand them.
All tools are linked to Amazon. We use Amazon affiliate links so you can find and purchase tools easily, with fast shipping and buyer protection.
It depends on the device. Phones and laptops are generally safe if you disconnect the battery first. Power electronics (chargers, power supplies) can retain dangerous voltage in capacitors — always discharge them before touching anything inside. Wear safety glasses when prying open enclosures.
Some links are affiliate links. If you purchase through them, we may earn a small commission at no extra cost to you. This supports the channel. See our full affiliate disclosure on the Legal page.