DBC/DBU2 problems, need advice(fixed)
 

<div>I just installed a DBC/DBU2 in my HL Panther G. It worked great at first, but now seems to be not working. After I installed it I had a small tank battle with my son. It was great fun, we killed each others tanks several times. A couple days later I had time to battle again so we had a second battle. Again no problems. Then it began to act up.</div><div></div><div>I noticed it would flash the DBU LED&rsquo;s briefly when I turned the tank on, then not start when I did throttle stick up. It will fire the IR and make cannon sound but with no muzzle flash, and no recoil. All the time the headlight is flashing and no motor response, no turret turn and no gun elevation. It will take hits from my Leo and make the death sound when it is killed but with no movement from anything. It&rsquo;s like the DBC is awake but the RX-18 is not. The controller is 5 channel and I have not plugged in the 5th wire in to the receiver, just the 4 standard ones. </div><div></div><div>I got it from Phil @ RCTankwars and he was very nice and responded promptly to my e-mails asking for help. Sadly, his advice did not fix the problem. His web page has a manual for the DBC and it mentions that the two PC boards can get out of sync if you shut off the tank the wrong way. I&rsquo;m not sure what that means. I followed the directions to fix it but it did not help. </div><div></div><div>Strangely, for the last two days in a row it started up perfectly the first time in the morning but then would not work for the rest of the day. Yesterday, when it started in the morning I packed the tank in the truck and went up to the mtns. to play only to have a dead tank when I got there. </div><div></div><div>I purchased this system so I could go over to Denver and Battle with FRAG on the 28th but at this point it is too undependable for that. No way am I going to drive 7 hours to a battle only to have a tank that won&rsquo;t start when I get there. </div><div></div><div>I made a movie that shows the problem&hellip; because a picture is worth a thousand words.</div><div></div><div>Turn on steps: Controller on.</div><div> Tank on.</div><div> Right stick up.</div><div></div><div>Turn off steps: Tank off</div><div> Controller off.</div><div></div><div>So, any help or advice you folks can offer will be wonderful. Thanks in advance.</div>
http://www.youtube.com/watch?v=7awVP...ature=youtu.be

RE: DBC/DBU2 problems, need advice(fixed)
 

If you haven't done so already charge up the battery to a full charge and see if you still have the issue

DBC are sensitive to any kind of short or a low battery. Anything that causes a brown out will result in them being out of synch. If you have the track recoil on turn it off. Make sure your battery is fully charged. See if there is a loose connection or anything that might be causing something to ground out.

Sometimes just turning off the tank and the radio and "rebooting" is enough to get them in synch again, and away you go.

Let me know if you are still having issues.

There may be a cold solder joint. If there is, and you are up for it, you would have to remove the DBC chip, and go around to all the pins and reheat them until the solder is shinny. You may be loosing the ground momentarily, and that is why this is happening. I had a customer have a problem with one as well. I was able to fix it by doing the above.

Cheers


EDIT
After seeing the video I think you should try replacing the 3 wire control cable from the RX18 to the DBC. If that doesn't work you may want to try heating up all the solder points on the DBC board.

RE: DBC/DBU2 problems, need advice(fixed)
 

The battery is fully charged. Reads 7.86 vdc I have tried turning off the tank and controler to "reboot" but it dosen't help. Sitting over night seems to fix it... once, then if I turn it off and back on it goes haywire.

I will inspect the solder joints next as I have checked all the plug in connections.

Thanks

RE: DBC/DBU2 problems, need advice(fixed)
 

Fully charged should be over 8 volts, I think mine are usually 8.4 when they go to trickle charge.


Anytime I had a glitch with it, it was a low power issue. The battery can still have charge, but if the tank is drawing heavy, it can be enough to drop, especially if you're using NiCads. I use the 1800 mAhs in my Tamiyas all day long, but the same battery in the HLs with 400 motors, metal tracks and gears, DBC and Benedini there's a lot of drain.

Once I switched to NiMH 4200mAh, never had an issue.

I know the airplane guys talk a lot about power draw on motors based on prop size, and it really matters. Even running through higher grass will draw from the battery more.

RE: DBC/DBU2 problems, need advice(fixed)
 

It's a 4500 ni-mh battery. I charged it up yesterday before I headded up into the mountains. Worked for 30 seconds in the morning but would not start when I got there. I'm charging a fresh one now.

RE: DBC/DBU2 problems, need advice(fixed)
 

Altitude sickness?

Certainly a good battery size.

I don't know what Tx you are using, but if I don't remember to center the left stick on my DX6i before I start up (and I usually don't), I end up starting the config protocol. Not saying that's the issue, just relaying everything that was weird for me and had an explanation.

RE: DBC/DBU2 problems, need advice(fixed)
 

It's a DX5e Spektrum. It has digital pots so it's hard to tell when they are centered. I push up till it beeps, then count clicks down till it beeps, then half the number of clicks up to center.

<span style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255); ">Altitude sickness?</span> Nice! <br type="_moz" />

RE: DBC/DBU2 problems, need advice(fixed)
 

The trims shouldn't matter, but the stick itself isn't self-centering unless you bought the kit or had them do it (if you purchased from Horizon). What happens with me is, if the left stick is up or down or I accidentally move it up or down before I push the right stick to start, then it's choosing from the configuration menu.

I couldn't figure out why the LEDs would be lit on startup until I realized what I was doing wrong.

RE: DBC/DBU2 problems, need advice(fixed)
 

I tried a new battery and went through the configure mode. The LED's on the DBU light up for each option I pick, but the up throttle will not start it so I don't know if it saved the options.

Could my throttle on the controler be the problem?

RE: DBC/DBU2 problems, need advice(fixed)
 

It might be. Try changing up the servo connections to the reciever. ie. Change the throttle for the turret. See it if will start under the control of the turret stick. You will also be able to check your throttle stick, as it now will be lighting up the DBU LEDS

Did you check the three wire cable and ensure all connections are good. I had a wire break off one time and it was hard to see it was broken.

Your battery seems more then adequate, and if the above all checks out and the tank still won't start, try reheating the DBC solder poiints.

RE: DBC/DBU2 problems, need advice(fixed)
 

The three wire tests good with my meter.

I have reheated one solder joint on the board that looked bad with no luck. I am going over the others with a 10x loup. I have soldered miles of stuff so I know that a cold joint is a bad connection.

I'm going to switch the servo connections after supper.

RE: DBC/DBU2 problems, need advice(fixed)
 

i hope it works for you let us know

RE: DBC/DBU2 problems, need advice(fixed)
 

OK.

I tried switching the servo plugs to see if it is the throttle stick on the controller. Nope. Still the same, just on the other stick.

I tried reheating all the solder connections on the board. No change. Before I reheated them all I looked them over with a 10 x loup and my OptiVisor, andI must say thatPhil does nice soldering. Clean, without too much solder.

I'm going to unplug the battery for the night and try it in the morning. It has fixed itself for the last two mornings, then the Gremlins wake up.

RE: DBC/DBU2 problems, need advice(fixed)
 

Sorry I missed the youtube link the first read through, I would have seen the centerred stick and the Tx.

I know this stuff can be frustrating to work out, for us as well as the guys who designed it.

I don't want to harp on the battery stuff, but what kind of charger do you have?

Do you have a spare RX-18 to try?

Second, I'm not familiar with the DX5, are there any gear switches or mix switches? I know with my DX6i, there are certain throttle fail safes or something that act weird when switching from planes to helis. I think I have to switch off one rate and the mix.

I'm reachin' here, but I feel your pain. Good luck.

RE: DBC/DBU2 problems, need advice(fixed)
 

<div>Here is a movie I took this morning.  In it I start the tank and everything works great, all the functions perform perfectly.  Then I turn off the tank and controller.  I turn them back on and it doesn’t work.  Just like the past two mornings.  Three days in a row it has done this.  I am beginning to believe in Gremlins.  Perhaps in this movie is a clue to what the problem is.  I’m still not ruling out pilot error. </div><div>
</div><div>http://www.youtube.com/watch?v=BvgFRLNhC5M</div><div>
</div>

RE: DBC/DBU2 problems, need advice(fixed)
 

Yikes.

That's beyond my scope of understanding. Can you hook up a multimeter in between the battery and the tank and see how it's drawing? Maybe there's some bizarre drain.

I know with lipos, even though they are rated a 3.7 volts per cell, it you run them to 3.5 or so, they are like 90% depleted. I mistakenly ran a 2 cell down to 6.8 volts (3.4 per) yesterday and when I charged it, it took 817 mAh, when it's only a 850 total. 3 volts is death and full is 4.2 per cell.

In my experience, electronics either work or they don't, they don't decided they way yours seems to be doing. The only outside influence is power.

But again, I'm just reaching here, I'm no expert by any stretch.

RE: DBC/DBU2 problems, need advice(fixed)
 

The battery read 8.42 volts before I ran the tank and it reads 8.16 volts now.  I will try what you said and see what the voltage drops to under load.

RE: DBC/DBU2 problems, need advice(fixed)
 

No voltage drop with the throttle stick up, should start the tank.  .02 volt drop when I fire the gun.  The only control that produces a voltage draw is the fire command...    Battery at 8.15 volts now.

RE: DBC/DBU2 problems, need advice(fixed)
 

I'm out of ideas.

I meant to ask, what are those two blue bundled pieces? They look like flash units.

RE: DBC/DBU2 problems, need advice(fixed)
 

You might try running some wire. Perhaps one of the traces on the board has a hairline break. I would start running the ground from the 3 wire receptacle to the Voltage regulator on the DBC, and then to the ground point on the Chip. Without a proper ground all kinds of things can start happening

Perhaps the temperature is playing into the trace problem. Maybe when it warms up something opens up and a connection is broken , By paralleling the key connections with wire you may solve the issue.?? Just something to try.

RE: DBC/DBU2 problems, need advice(fixed)
 

I don't own a DBC so take that to heart but,<div>does the DBC shut down the tank if you move the stick all the way up when it is running?</div><div>it appears to me that shutting off the tank with the power switch is possibly leaving a charge on the system and the electronics are hung up in a loop or they are in the middle of an executuion. It takes a while for the charge to leave the system and that is why you can restart the next morning. </div><div></div><div>Like I said I don't have a DBC but that is what it appears to be.</div>

RE: DBC/DBU2 problems, need advice(fixed)
 

Phil has been in contact with me and is working out a solution.   He is great to work with.  Not many like him left in the market place. 

The blue bundles are sound cards, I think.  It has cannon sound, hit sound and death sound and I think they are on seperate sound cards.

The shut down step is sort of confusing.  There is two ways, failsafe and without failsafe.  I'm not sure what type I have so that could be the problem.  Phil's web page has the steps listed and up throttle turns it on but is not mentioned to turn it off.  I did try that but the tank just drives.

The time intervel to self repair does make me think that a charge has to bleed off to reset a switch somewhere.  I'm leaving it alone all day today to test that.  I will try it tonight to see.

RE: DBC/DBU2 problems, need advice(fixed)
 

Hi Its been a while since i played with one of these ,but if its powering up allowing you to select modes ,but not starting ,I would say Dan is on the right track ,its not sending signal to the RX18 so I would redo  the three wires to the RX18 and check the tracks of these for breaks,its probably a dry solder joint or a broken wire cracked track.But limit your search to these wires and tracks .

 regards pete

RE: DBC/DBU2 problems, need advice(fixed)
 

Failsafes might be the key.

I love Spektrum, but the 5 and 6 aren't surface Txs even though they can be used as one. Horizon has a lot at stake with liability and swinging props. There's tons of threads of people chewing up hands and legs, so they build safety measures into what they can. Usually nothing will work until the throttle is set all the way to zero. Maybe between the self centering stick and a failsafe, something is being triggered on shut down.

I'd look over your DX5 manual and see what it has as default. I know there are ways to program them out of failsafe.

RE: DBC/DBU2 problems, need advice(fixed)
 

I am sure Phil will figure something out with you. Sometimes that track recoil plays havock with the DBC. On a DBC3 with a Benedini, I tell people they should run without the track recoil.( Most people want to get rid of it anyway) It is a real good power drain with both motors suddenly kicking like they do. Any model of DBC hates a brown out!!!!!!. Usually turning the tank and transmitter off and on will clear a problem caused by the track recoil. In your case it didn't though, and that is why I still think you might need to run some wire across the key grounds on the board. If you do have a wire trace problem or other wiring issue where something is shorting out , that recoil jerk will also contribute to moving some loose wires.

Keep us posted, as I sell these as well and have an interest in making sure this gets resolved. Just so you know you are not alone. I also had to resolve a similar issue with a customer of mine as well.