Is your Xhorse VVDI Mini OBD Tool refuses to update, won’t connect, or has stopped syncing with your devices? According to one experienced technician, the most common culprit isn’t a software glitch—it’s a dead or dying battery.
In this guide, we’ll walk through a complete disassembly, battery replacement, and reassembly to bring your Mini OBD Tool back to life.
The Problem: What Goes Wrong?
The tool had two classic symptoms:
Would not sync with the app
Would not update properly
After troubleshooting, the root cause was traced to the internal battery. This is apparently the most common failure mode for these units. The good news? It’s repairable. The bad news? Getting the case open is a fight.
Tools needed:
Small screwdrivers
Soldering iron
Desoldering braid (recommended) or solder sucker
Replacement battery (CR2032 or similar with 180° tabs)
Silicone and black marker (for case touch-up)
Super glue (for label)
Step 1: Disassembly – The Hard Part
The Mini OBD Tool is tightly sealed. The cover is held on by small tabs (ears) that make it nearly impossible to remove without damage.
“Although you can reach the edge of the piece, when you try to pull it out, it’s hard—very, very tight.”
The technician ended up having to use significant force, which caused some cosmetic damage to the plastic. His advice:
Accept that you may mar the housing
Plan to seal it back with a little silicone
Use a black permanent marker to touch up any scratches
Bottom line: Be prepared for a tough opening. Work slowly, and don’t expect it to come apart easily.
Step 2: Removing the Bottom Cover & Screws
Once the top cover is off:
Remove the label on the bottom (marked USB, LF)
Underneath, you’ll find three silver screws and two black screws
Important warning: There are small nuts on the other side of these screws. If you flip the board over, the nuts can fall out and get lost. Without them, the case won’t close properly.
“If you turn the piece over, the nuts come out, and if you lose them, the piece won’t close well.”
Step 3: Separating the Two Halves
The tool consists of two main sections:
One side connects to the vehicle’s OBD port
The other side handles processing and communication
Between them sits the battery, along with a small foam pad (bearing) on top and another on the bottom.
Step 4: Removing the Old Battery
The battery is soldered to the board. The technician’s method:
Heat each solder point until it melts
Add a tiny bit of fresh solder to help everything flow
Give the board a small tap while the solder is liquid
Repeat on the other side
The battery came out perfectly with no damage to the board.
Critical: Preserve the foam bearings (small pads above and below the battery). They prevent the battery from vibrating or touching other components. A loose or improperly seated battery can destroy the tool.
Step 5: The Surprising Replacement Battery Source
Here’s where it gets interesting. The battery you need is the same one found in Nintendo 64 cartridges.
“If you have a Nintendo 64 cartridge, you can take the battery out of that cartridge. It’s exactly the same—180° brackets, one on each side.”
The technician bought a pack of replacements for about $2.50 (250 of whatever local currency). But in a pinch, a working N64 cartridge will donate a compatible battery. N64 cartridges are nearly immortal, so the battery inside may still be good.
However: This is only a temporary fix. Always install a fresh battery for long-term reliability.
Step 6: Soldering Techniques – Clearing the Holes
Before installing the new battery, you need to clear the old solder from the through-holes on the circuit board. The technician offers three methods:
Option 1: Toothpick Method
Heat the solder until fully liquid
Push a toothpick through the hole
Quickly remove the toothpick before the solder resolidifies
Option 2: Solder Sucker (Extractor)
A vacuum tool that sucks up molten solder
Requires practice to get the angle and timing right
Very effective once mastered
Option 3: Desoldering Braid (Recommended)
Place copper braid over the solder joint
Add a little flux
Apply the soldering iron on top of the braid
The braid absorbs the molten solder
“It’s very easy to do with braid. This is the way I recommend.”
After cleaning, the holes should be completely open and ready for the new battery.
Step 7: Installing the New Battery
Polarity is clearly marked on the board: Positive and Negative.
The top of the battery is positive
The battery is rotated 180° compared to some others, but the markings make it foolproof
The positive side goes toward the pad labeled positive
The technician had to trim the battery’s legs slightly because they were longer than the original. Standard wire cutters work fine.
Step 8: Reassembly Tips
When putting everything back together:
Insert the battery with the foam bearing properly seated underneath
Solder the legs in place
Reinstall the foam bearing on top
Carefully close the case—watch for those loose nuts!
Don’t forget the lanyard (hanging strap). Install it just before final closure
The LEDs on the board face downward toward the bottom of the case
Step 9: Securing the Bottom Label
The bottom label may not stick well after removal. The technician recommends:
A light brush of super glue (cyanoacrylate)
Apply a thin line at the top, middle, and bottom
Use very little—just enough to hold it in place
Future removal is still easy because the glue layer is so thin
The Result: Fully Functional Again
After reassembly, the technician connected the Mini OBD Tool to the Titan app.
“Now it says it’s syncing… and done, synced successfully.”
The tool now:
Syncs without issue
Shows the latest software in the update center
Communicates with the server
Reads pins (the primary use case for this tool)
The Xhorse Mini OBD Tool repair is moderately straightforward—except for opening the case. That part is genuinely difficult and may leave marks. But if your tool has stopped syncing or updating, a dead battery is likely the cause.
With patience, basic soldering skills, and about $2.50 for a replacement battery (or a donor N64 cartridge), you can bring your Mini OBD Tool back to full functionality.
www.vvdishop.com
