Well, my Pz III seems to be dead today.

After running it for about 5 minutes in the morning outside, I turned the tank on this afternoon and the lights simply blink... when I press the ignition button on the transmitter, the tank won't start, the controls don't respond either. I tried turning off the tank and the transmitter and repeating the whole process but nothing. However, after a few tries the tank did start up and function normally again. So I turned it off thinking maybe this was just something temporary. Now, when I press the ignition button again, the same old problem occurs, the tank just sits there blinking...

My batteries are fully charged, a voltmeter test revealed 7.62 V. As for the batteries in the transmitter, it registered ~ 10.4V (with new AAs it usually reads ~11V).

My board is the new RX-14 so I don't think it has fried, the lights blink so power must be flowing. My assumption is that something must be blocking the signal from the transmitter to the tank. I checked for loose wires but everything seems to be intact, opened up the transmitter and everything seems to be fine. The only mod I've done to this tank up until now is using bits of styrene to seal off the suspension holes in the lower hull, this works well since I've ran the tank in about 2 inches of snow with the inside compartment being bone dry after check-up.

So could something have shorted out? I've been extra careful in handling the electronics so I'm a bit puzzled by this...

Thanks for any help.

Swap out the crystals with your spares. You do, you do...

I would make you a bet it will turn out to be your crystals,and the bad one will be in the receiver board. BIGMIG

Sometimes the batteries don't seem to set right in the Heng Leng transmitters. I have had this trouble as well and it has always been poor battery connections in the transmitter.

Can't believe tank is dead - that's a good thing !
But as a driver you'd have another HL available = Yes
can't imagine any driver having just the one tank

I'd start with eliminating the transmitter, swap crystals over first

I have a Futaba crystals set on 75mhz FM , would this work?

Also, are crystals also governed by +/- poles? I don't see any markings so I'm guessing this doesn't matter...

This will give you the chance to visit the Mato web-site and order a set or two.I have used RC RED HAWK crystals ordered from tower hobby for a little less than $5.00 dollars and $3.99 shipping.I bought 3 sets and the shipping covered them all.I think your transmitter and receiver require 27 MHz FM crystals.Crystals just plug in and it don't mater which direction they face(but there is one for the tx-transmitter--and one for rx-receiver). BIGMIG

Thanks for your reply Bigmig, since Mato doesn't sell the sets separately I guess I have to order something else along with it... On another hand I could desolder a set of 27mhz crystals off some Radioshack RC cars but I don't know if those are FM or not.

Are you positively sure that they have to be 27mhz? It's a shame I have to wait another few weeks to tank again.

They are FM--and the ones I know that work--From tower hobby--Flyzone HCAL7505 Crystal set 27.195 MHz RC RED HAWK--
( i have these and use them and know they work in HL tanks). You can go to tower and see how much they charge to ship to Canada
(if they do). hope this helps you--BIGMIG

Are you sure? [] i always thought that they were AM.

Thanks again! Are you talking about the Radioshack RC car crystals? Seems to me that most RC toys use AM...


Is this a common occurrence in HL tanks? I've only played with it for maybe a total of 2 hours and can't believe that already something broke... plus I don't think it's the receiver battery connections either, the red LED shines brightly so there must be power flowing.

What are the usual signs that indicate a fried board or a break in the circuit?

Well the ones I ordered from tower are the ones stated above and they work in my tanks.I'm pretty sure all the S&S tanks use fm crystals,But I could be wrong.The symptoms you described are usually the crystals,when one or the other of the set goes out (the transmitter and receiver can not comunicate with each other.If the board goes(it usually is just some features that quit working,allthough sometimes it will smoke and self destruct the board itself).There is most likely nothing wrong with the boards at this point.I have had several tanks do the same thing your's is doing and it was just a bad crystal. BIGMIG

P.S. I'm pretty certin the S&S radio's are FM because I don't think you could get AM radio to work with FM crystals or visa-versa.

also i have noted the solder jobs are piss poor i had a dead board just reworked the solder it was all ok then
but the very first unit i pulled out had a dead rx crystal so a process of elimination

i noted that the reciever board when you push down on it it would fire up ok as soon as you took the presure of it would die again so i reworked the solder and that fixed it
also had a problem with one motor would not go forward so i reworked the solder on the main larger board and that fixed that hmmmm
pays to have a good soldering iron for doing smaller electronics on hand

Check for lifted tracks on the receiver board (the little roads between components), check antenna wire is on their solid, then check crystals (the 75mhz ones you have wont work) are firmly seated in their sockets tightly and that the batteries are truly charged, as that can cause these exact symptoms

I always slightly bent the crystal legs outwards to guarantee good pin contact with the sockets.

GOOD: (o) (o)
BAD: ( o ) ( o )

To throw in my worth the circuit(s) is(are) a narrow band FM system.

Yours Simon M.

Same thing that happened to my Tiger. Lights would flash, smoker worked, but wouldn't start. After a good nights sleep tried again the next day and the lights wouldn't come on, but the smoker still worked. I spent $25 and sent it back - I never did hear from Mato about the problem, or if they repaired the problem or just sent a new one, but they shipped me something Wednesday so I should have a tank in a couple days.
Good luck with it... frustrating, but I guess it comes with the territory, and like they say, the real ones broke down too.

My tank is revived!!!

Wacky, thanks for your input. I noticed that one of the contacts on the Tx crystal socket was slightly bend outwards so I took a tweezer and adjusted the contacts a little bit. At first this didn't work but when I flipped the Tx crystal (switched the pin positions) and pressed the ignition button, the tank fired up right away and was functioning normally again!

However, the turret rotation seems to have changed a little bit. Here's what I mean: even though the left control stick is not proportional, usually by giving it a slight flick (left or right) the turret would rotate just slightly (maybe 20 degrees). However, when I flick it now, the rotation arc is almost double as it used to be... The turret would rotate smoothly if I held the stick before, but now I can hear the motor stuttering every few seconds as it turns. Throttle control seems to be unaffected.

So would these crystals damage my boards if I kept using them? I'm contacting my LHS to see if they have crystals in stock.

Excellent Nemo!

Crystals can go either way, I'm unsure if using incorrect crystals can damage the boards. With the control lag, the only times I've had laggy controls is if either of the batteries are flat OR if the antenna wire is missing, broken or poorly soldered, or the tank is right on the transmitter's range limit. Check the wire, make sure its not crimped or damaged, and that its soldered on well. Another possible cuprit is the little washer soldered to the antenna wire end is oxidized or just not making good contact.

Always check the crystal sockets when changing crystals, they can easily be bent out slightly: one leg might sit in firmly, but the other just sits in mid-air, because the contacts in the plug are spaced too far apart [8D]

An update.
I wrote in an other tread that my tank didn't work.

Well, I tried all the suggestions without success.
Finally I bought new crystals from Tower Hobbies.
AND now the tank is running again
Thanks !!

Excellent. I dread these "my tank is dead" threads but thankfully its usually something simple that is easily/cheaply fixed.

Well done to those who took the initiative and fixed their tanks on their lonesome!

Wacky you the man,where in the world did you get all that knowledge.?? I think from now on you will be the RCU tecnician,We will send all the tank problems directly to you.I have been taking a lot of notes and I'm shooting for your abilities[
BIGMIG

before you go shopping crazy.. which i would do anyhow [&:] pull the crystals and make sure contacts are clean etc and put them back in. see if that dose it. if you got the tank open check the antennae wire to. have you tried "starting" the tank with the transmitter close to the tank? like within a foot?

Mine too but with different symptoms. Mine does a normal startup but when when the transmitter stick is moved foward (throttle) the tank dies, when moved backwards the sound level drops to zero and no movement is observed. Lights and turret functions are ok RX13 board, changed crystals, changed transmitter and receiver batteries, changed transmitter, same story. Have not done a detailed inspection of the board yet but that will be done soon Sounds like the main board to me but what do you all think?

sounds to me like a dead short on the board[X(]
check for loose wires and the like when you have the chance[)]

hopefully you find the short before the board dies[)]