Help with T99A issues.

[tankme]

Could be the LED is soldered in wrong or the LED is bad. Either way it is clam shelled in between two glued together pieces of plastic in the tail light housing. It would be hard to separate without damage. It would be much easier to just get a replacement tail lamp assembly. Toucan Hobby is pretty good from my experience with them. They refunded my money on two gearboxes when they got lost during Covid. When they finally did arrive, they gave me a discount on them for the inconvenience.

[dai phan]

Not to offend everyone that has responded already, but you can ignore the soldering comments. Those that don't have the ZTZ tank or seen the way the LEDs mount on it would not know what the issue is. The ZTZ model tanks seem to have a unique way they mounted the LEDs. Unlike most of the regular Heng Long tanks the rear three LEDs are mounted on a small PCB board and then wired to a singe + and - wire.





The legs of the LEDs are not just pushed through the chassis and have cables soldered on. They are actually plugged into one JST connector each. On my ZTZ-99 (non-A) version I had to install the rear LED lights myself as they weren't installed at the factory. The tail light part actually has two metal leads coming off of it that plug into the JST connector on the bottom of the rear track sponson.



If one of your LEDs is not on, then yes it is most likely bad because the other two work. The entire tail light part can be replaced pretty easily without any soldering, but if it is glued in it will be a pain to get out. This is the replacement part you need and a link below as to where you can get one if Toucan Hobby doesn't send you one:



https://www.aliexpress.com/item/4000249 ... web201603_

Thank you so much for your guidance. I think the LED is bad so TH is sending me a replacement along with a new cable. I look at the cable and did not see any faults. The connection is secure. I did not glue the tails lights on because I see potential problem of replacing them in the future. Dai

[dai phan]

I think the two parts that are coming off are the metal upper track return rollers. I have the plastic return rollers and they are only press fit in on my tank and mount differently. Seeing that those metal ones are hollow, I personally would use a very fine thread screw and washer on the inside of the tank to hold them on. Glue could also work, but it may not hold permanently.

These parts do not go through the holes so the only option is to glue them on? Press fit will come right off.
Dai

[tankme]

I'm glad they are taking care of the issue for you. Like I said, I've ordered from them before and they are good about taking care of issues.

That's strange about the metal return rollers because the plastic ones have a little metal rod that goes through the chassis and I can see it inside. In that case I would either glue them in or still do the fine threaded screw. I would just have to drill a small hole through the chassis plastic for the screw to go through making sure it's a smaller hole than the shaft of the return rollers. I have found that even though Heng Long sells "upgrades" that not all upgrades are "easy" or straightforward for that matter. If you do use the screw method make sure there is a washer behind the screw head on the inside of the chassis.

[dai phan]

I'm glad they are taking care of the issue for you. Like I said, I've ordered from them before and they are good about taking care of issues.

That's strange about the metal return rollers because the plastic ones have a little metal rod that goes through the chassis and I can see it inside. In that case I would either glue them in or still do the fine threaded screw. I would just have to drill a small hole through the chassis plastic for the screw to go through making sure it's a smaller hole than the shaft of the return rollers. I have found that even though Heng Long sells "upgrades" that not all upgrades are "easy" or straightforward for that matter. If you do use the screw method make sure there is a washer behind the screw head on the inside of the chassis.

The metal rollers have the holes at the end but no holes for the screws at the chassis so I glue them in. It appears that all rollers are press fit and they will come off after few minutes of run. Dai

[dai phan]

Not to offend everyone that has responded already, but you can ignore the soldering comments. Those that don't have the ZTZ tank or seen the way the LEDs mount on it would not know what the issue is. The ZTZ model tanks seem to have a unique way they mounted the LEDs. Unlike most of the regular Heng Long tanks the rear three LEDs are mounted on a small PCB board and then wired to a singe + and - wire.





The legs of the LEDs are not just pushed through the chassis and have cables soldered on. They are actually plugged into one JST connector each. On my ZTZ-99 (non-A) version I had to install the rear LED lights myself as they weren't installed at the factory. The tail light part actually has two metal leads coming off of it that plug into the JST connector on the bottom of the rear track sponson.



If one of your LEDs is not on, then yes it is most likely bad because the other two work. The entire tail light part can be replaced pretty easily without any soldering, but if it is glued in it will be a pain to get out. This is the replacement part you need and a link below as to where you can get one if Toucan Hobby doesn't send you one:



https://www.aliexpress.com/item/4000249 ... web201603_

The site says I will get the parts next year in February. Does it really take that long? Dai

[tankme]

I have ordered some parts from that company and it is now going on 3 weeks waiting for them so it can take a while.

[dai phan]

Hi all,

TH sent me the replacement lights and I got the problem solved. But after running the tank for 5 minutes, the tank stops making turns or even moving forward. The sprocket shafts now do not move with the motors so the motors need to be replaced. To be honest I am getting tired of this crap. Same thing happened to my HL Panther G. Very typical of Chinese engineering. Dai

[dai phan]

I open the tank and inspect the gears carefully. No broken gears, no falling out shafts. Everything is snug. Every screw is tight everywhere including road wheels, idlers and sprockets. The sprocket shafts turn when motors are on but on the ground, the tank barely moves and cannot do spin. Looks like the motors simply does not have the strength to do anything except freewheeling. The battery is Admiral 7000 mAh fully charged. My guess is one or both motors are bad. Comments please. Dai

[abramsky]

Hi
It's really bad luck to have so many failures in such a short time. If you are familiar with the multimeter, take a measurement of the voltage the Engines receives from the MFU ESC when you give it full throttle. Do this first when the tracks are off the ground and the second on the ground. You can put the multimeter in the lower hull and disconnect the upper one while the tests. Then you can check how much current each motor consumes while driving (it should be around 2A). Be careful. You measure the current separately for each of the motors and multimeter must be connected in series with only one wire ( eg. red one ), otherwise you will short the MFU ESC circuit. You can also (FOR A MOMENT) Block the sprocket of each track separately and see what is the max current. It should be around 10A. The safest way to do this is to connect the motor directly to the battery. Be careful to only do this for a while (1 second should be enough).
If the voltage supplied from the ESC of your MFU is correct (with throttle on max it should be the same the battery voltage ) you can try to swap motors from another model and see if there is an improvement. All these measurements to rule out MFU failure if the motors are OK.
Good luck