I own a single HL Sherman that I bought about 4 years ago, and I would drive it in my backyard about once a week, every two weeks. It was only very recently when i started to drive it in more difficult terrain, such as small puddles and thinner mud.
Anyways, I was driving my sherman in my backyard the other day when all of a sudden, the tank disconnected from the transmitter(went lights flashing mode). I tried to re-start the tank(through the lock key) however there was no reaction. At that time I had just assumed it was a battery issue and did not pay too much attention to it.
I then re-charged the batteries, tried the startup process again, yet the tank still didn’t start up. It went into lights-flashing mode when I flipped it on, but did not start when the lock key was pressed on the transmitter.
I tried replacing the batteries in the transmitter, yet it still led to the same result. Re-binding the transmitter to the tank, however, did start up the tank. Unfortunately, despite being in started-up mode, the tank did not react to any of the controls being manipulated. No track movement, turret traverse, nothing. It just sat there idling like a stone.
After attempting to re-bind the tank multiple times(due to it being the only method of starting up at the time), i was finally able to get a bit of reaction from the tank when I lightly moved the controls, albeit very delayed. Thirty seconds in, the tank then became unresponsive to any controls and continued to idle like a stone.
I attempted this process over a course of multiple days. Every day, i was able to get a bit of a reaction from the tank. Sometimes, the delay would lessen significantly, but the tank would still become unresponsive after a minute.
Does anybody have an idea of possible causes to this issue + potential remedies or spare parts i could buy?
Much appreciated yall!
Hello, same diagnosis as my friend above. How can we be sure? that no humidity in the circuit? that your battery (accumulators) is well charged? What is a CBB battery, what type, has your tank already worked? before this problem, type of charger used? As I often say, a discharged battery will provide enough voltage (volts) to operate lights or others at low consumption, but if it requires high capacity (Amperes) type motors? will not work. Then to be sure that there is no humidity in the plate? you have to open it and see if anything is oxidized. Also see level of all the plugs, and first, that of the battery, if in addition a Tamiya? recurring problems with this model. Voila, after that it's just a personal opinion. Attached is a photo of a precious and essential tool? a Multimeter.
As for any problem? The first thing is to ensure the good condition of the battery, voltage (volts) and capacity (amps) after that it's just suppositions? but you seem sure that humidity concerns? without having opened the plate? see condition of the IC, oxidized or not? in troubleshooting there is a methodology to respect, and without a minimum of tools and knowledge, and short of a miracle, you seem convinced of the good health of your batteries? (possible) but you have no means of control? Moisture in the plate? if you don't open it?this is just guesswork!! (personally don't really believe in it?) but possible, a bad connection? here too, check carefully, and you also need a minimum of tools and electrical knowledge. Otherwise, and unless there is a miracle? We are going in circles. 
It could be that the transmitter is binding correctly (as evidenced by your brief experience. Could the batteries and/or connections in the transmitter be a problem? A voltmeter would be great for testing the transmitter batteries. Or one could just get fresh AA batteries in the transmitter. Then try to ascertain that all the batteries are seating fully in the transmitter. I have encountered HengLong transmitters that did not contact the batteries well enough, but only needed a little careful bending of the contacts.