Faulty Bee Bot Junior School educational robot

You might check the two electrolytic caps, are they bulging at all ? Thats
a sign they are failing.




I noticed in manual the soldering on the boards looks pretty crappy, you might
inspect with a magnifying glass for any poor connection.

These 4 connections in manual, notice how lower right lead seems not to have
solder wicked fully around it......



These do not look great either :



Google "good solder pcb connections" and look at images found in your browser.
PCB Flux helps a lot.

Regards, Dana.

Measure the battery voltage under load. If it drops significantly, the Bee-Bot may be resetting due to a low-power condition. Clean the battery terminals and contacts inside the Bee-Bot.

Dana. Thak-you for your thoughts. I checked the Caps and they are fine. When initially reading the service manual I thought I'd be replacing those charger PCBs given their poor quality, but the ones I have are much better quality, so perhaps they've changed their supplier. The batteries all charge and then hold their charge for several days afterwards. The main PCB also looks in good condition. too.

Ahsrabrifat, Thank-you. I've checked the battery voltage under load for both a working and a non-working Bees and both exhibit the same small change in voltage, but only dropping by 100mV or so when the Bee is moving.
The fault still exists when I hold the Bee off the ground when there is less load.
I tried swapping a batteries with a good Bee, but the fault stayed with the Bee, not the battery, so I'm reasonably confident it's not the battery.

I'm baffled by what could be resetting the device after roughly 8s. It's unlikely to be a bad connection, otherwise the timing would be more random. I'm next going to look for a voltage regulator and see if there's any drop on the regulated side. It's handy to have both working and non-working Bees to compare, though!

Thank-you again for your thoughts.
Regards, Clive

I have literally just had the same problem occur with my school's Beebots! Programme a series of commands and they stop after following 3. Mine are the transparent ones as opposed to the older yellow ones!

Clive - I would be interested to know if you get to the bottom of this!

Regards
Ben

Hi Ben.
I've not managed to get any further on this one, but I have three yellow "Bee bots" which are all working and four transparent "Blue Bots", of which three are faulty. Now the Blue Bots have much more on the main circuit board and have bluetooth (hence "Blue").
As the fault so repeatable, it's not a bad connection or faulty battery. I've tried swpping over batteries and the fault stayed with the same robot. When connected with the phone app (by bluetooth) when the bot stops it also drops the bluetooth connection, so it must be doing a restart. I think the main PCB needs to be replaced.
My next step is to try to contact TTS support, as this same fault was being reported in 2019, so they must have sorted it by now!