RC Tank Warfare community hobby forum

I found my old walker bulldog tank in my store room,(with the sound,gun, front light, smoke unit, variable resistor, smoke unit switch removed) and when i tried starting it up, nothing happened. After a few tries i got frustrated and used a 3000mAh battery instead. After the third time switching on the tank, some white smoke came out of the Rx-18 and melted some wires. After doing some repairs the tank still does not function. Please help!!!!!

You let the magic smoke out. Rule 1 about electronics: they only work if the magic smoke is still inside.

You mention some 'repairs' - what repairs specifically? If those repairs don't include 'completely replacing every damaged component on the RX18 with like parts using my expert soldering skills and various electronic measuring tools' (which I doubt, because if you were capable of that you wouldn't have posted this thread) or 'completely replaced RX18 board', then you're probably out of luck and are going to have to replace the RX18 board. It's dead.

Welcome jian....What I have to say isn't good news... there must have been a reason that Walker was where it was... couldn't be that old as it had a RX...but it does sound like someone did some fiddling with your electrics... the smoke coming from your RX really means that tank is pretty much dead...Something I would relegate to parts...as it does seem you will need to start your internal rebuild from scratch...It just seems more logical to purchase a New Walker ...if you like that model.. and strip what you can off of this one

Enjoy your adventure

ALPHA

Hi First thing to check when it wont start is the crystals on the receiver and the radio(also check they are the same frequency) ,if they havnt been used for a long time they need to be taken out cleaned the just bend the legs a tiny bit to make a good contact. then try again if the headlight comes on full instead of flashing it has switched on ,if it dosnt move the board has fried ,you need a new one.

regards pete

So do you guys mean i need to replace the rx-18?
And Lert, I only replaced the molten wires, i did nothing to the rx-18, and how to check whether the rx-18 needs to be replaced or not?

seejianshin wrote:how to check whether the rx-18 needs to be replaced or not?

At this point, I'm 99% sure you need to replace it. However, to check ...

Make sure you've got the proper battery and it's properly charged. Hook it up to the tank. Turn the tank on. Does the light start flashing?

Wait ! the fact that wires melted indicate a short , that needs fixing first . Which wires were they ?

Lert, the light flashes all the time. As for blimp, they are the wires from the receiver, and the power cable is slightly damaged. I really think it is caused by the 'magic smoke' from the rx18. Plus, can the tank function without most of the electronic parts(say the gun)? Can the transmitter and receiver work without the crystal thing???

Without gun yes maybe, I have one that does everything but "gun" due to airsoft was in a sequence that acted as a very high load (I could see the chip glow, it was under the motor FETs), needed to be taken apart and made sure no gearmesh was happening with piston, replace RX18.
Haven't tried no crystals, but would think a big no-go.

Really hope things work out, these tanks are fun.

As far as I understand, this is how the electronics are set up:



The red lines denote something going from the module to the RX board (power in the battery's case, signals in the receiver's case)
The green lines denote something going from the RX board to the module (a combination of power and signals in all cases)

What normally happens when you flip the 'power' switch on the underside of the tank is:

1) The RX board receives power and boots up. This happens very quickly.
2) The RX board starts sending a 'stand by' to the headlight. IE: blinking.

So if you turn the physical power on and the headlight starts blinking, that shows that at least that function of the RX board still works.

Then when you switch the TX (the transmitter hand unit) on and press the key button, the following happens:

3) The receiver hooked up to the RX board receives the 'soft power on' signal from the key button press on the TX hand unit and sends that signal to the RX board
4) The RX board goes through its 'wake up' sequence: playing the 'engine start up' sound
5) When the wake up sequence is finished, the headlight starts burning uninterrupted and the engine idle sound plays. Now the tank is ready for play.

Any external function (with green line) is a separate entity and will function independently of each other. IE, you can run the headlight and turret functions without hooking up the motors, or run the motors without hooking up the headlight or turret functions, or any other combination.

Now, how the signal between the TX handset and RX board works is as follows:



A control input (IE left stick forward) goes from TX handset controls to the transmitter, through the crystal,to the antenna, is transmitted to the antenna of the tank, goes from there through the crystal and receiver to the RX board.

By trying to operate without crystals, you're removing two key components that are required for operation: after all, without a crystal in the TX to give the signal its proper frequency, it can't get transmitted from the TX. And without a signal in the receiver to decode the frequency of the incoming signal, it can't go from the receiver to the RX board.

I hope this answers some questions and clears up some of your confusions.