Repairing Hexa

During my time at MOD. I purchased a Vincross HEXA as part of our robotics education program. It’s a beautiful six legged robot that can be controlled via a mobile phone app, or their MIND SDK.

Fast forward to a couple years down the track, and I’m now working for ACMI on their renewal project, but still miss my old colleagues, museum and robots dearly.

When I heard that HEXA wasn’t charging anymore I jumped at the chance to debug them, and see if I could bring them back to life.

I suspect that the batteries and/or charging circuit might be dead. We had it replaced under warranty once while I was at MOD., so it’s a likely repeat offender.

Tools

My goto tool kit for computer/phone/robot repairs is my ifixit toolkit. The tools needed for this repair so far are:

• H1.5 hex bit (of course it’s a hex bit)
• PH0 phillips head bit
• PH2 phillips head bit

Disassembly

I have to hand it to Vincross, they did a great job of designing HEXA for disassembly – almost making it too easy to access the batteries.

After removing HEXA’s white head case, undo the 4x H1.5 screws on the purple head plate.

Warning: Be careful when lifting it off not to pull on the flex cables that connect the cameras and headers to the motherboard.

From the front of HEXA, gently open it up and pull up the two black flex cable connectors. Then gently pull up the other 8-pin black connector (J513).

Now that you have access to the motherboard, gently pull the two connectors off, and unscrew the 4x PH0 screws holding the motherboard down.

Next you can unscrew the 2x H1.5 centre black screws holding HEXA’s black bottom motherboard assembly plate.

This will show two long slots held in place by 2x PH2 phillips heads screws. Undoing these and using a sharp tool to prise them open will reveal the batteries. Success.

The two batteries powering HEXA are:

• Panasonic NCR18650GA 3.6V 3450mAh 12.42Wh

Next step: test the batteries.

The batteries were both reading 0.0v – so they’re most probably dead. Next step is to buy some replacements to see if the rest of HEXA is still okay, and if the charging circuitry is still alive.

While I wait for new batteries to arrive I’ll see if I can revive the old ones with my charger.

Update

Unfortunately neither the revived old batteries, or the new batteries that I purchased powered up HEXA. So I’ve asked for help debugging the various circuit boards on the Vincross forum.

Update #2

8th August, 2020: I got a response from Vincross, and they’ve sent me a PDF with instructions for disassembling the servo & charge compartment, pointing to some pins on the charging board that they suspect may have desoldered themselves with the heat of HEXA being left on the wireless charger for a long time.

Here’s an image of the pins they suspect:

And the PDF if you want to read the full instructions: