I have a question for all you DBU owners out there.

I connected my DBU to the DBC in my panzer 3 tonight and noticed something strange.

After I powered up and hit the engine button, the LEDs remains lit on my DBU. Is that normal?

Nope not normal, you got anythingto shoot it with? Try getting another tank to shoot it and see if you get 'hits'. also check your chip on the DBC and see if you installed it correctly, oreintation or skip a leg or bended legs. Btw did you remove teh chip from the chip holder before sholdering theholder on the board?

Yes. I will take some pics and send them to David and see what he says.

Tim

Here are some pics of what I have done. I have been in contact with Dave, but if anyone can shed insight (ie YHR) please do.

It lookslike you have your 5 volt line wrong! What does the yellow markings on the green wire signify??? Na if that is conncted to the 5 volts it's OK. IT's hard to say from the pictures what about checkin the basics starting with the seating of the main chip of the DBU! Then double check all solder joints i use connectors for all board mounted wires, but if that is all you have, just seat them better, ohm them out, and go from the there!

The Blitz

Make sure you have the five wires to the DBU in the right sequence. IF you are sure these are right then try resetting the IC.

Before you hit the start button did you see if the DBU lights up with movements to the Left joystick?. Full stick in either direction should make the DBU light up. You configure the system this way, and it is a good test to see if things are OK.

Your wiring seems OK, but make sure the DBU 5 wires are correct. You may have them in reverse.

I have triple checked the DBU leads and they are correct. The Green 5V wire (the one with the paint on it) goes from the DBU 5V to the DBC 5V. I wish it was that simple.

I'll check the main chip again. There may be one questionable solder on the LED-, but if that was bad then the LEDs would not light up. GGGRRRRR![:@]

It looks like you have a version 1.0 board, the jumper at R4 should not be cut according to instructions on his website (Step 4).

Tim,

You know I have had a few things that I have experienced but the only time all lights are on is when like 'YHR said your doing some programmming, or if I have a bad connection at some point to the DBU, orrrrr if the battery to the tank or radio are getting low! I now use a 9 pin din connector to mount my DBU because that is the week link in the system if you are battling in some rugged terrain!


The Blitz

A low battery was the culprit for me once. Never had the lights on issue, but the IR led would not pulse. I trouble shooted the DBC for hours, but int the end it was a low battery.

I did get one chip one time that seemed faulty. I was having issues with one of my boards. I swapped out the IC and the troublesome board worked fine. Have you got another board that functions fine? If you do try putting the suspected faulty chip in the functioning board and see if it behaves the same. If it does then you have found the problem. It is not out of the question that the PIC has a programing glitch in it.

I have a jumper in R1 as per the instructions. Is that right?



Does the IC control the DBU, DBC or both?

I wonder, if it is possible, that the vertical on the left stick on the controller is out of calibration. I disabled the airsoft when I put the new barrel in, so I would have no idea if the controller was sending a signal (up on the left stick) to the DBC, hence the LEDs going on.

Tim,

If you have purchased the board within a month or two you have the latest board! If you are going to post trouble shooting on the forum you need to go step by step! The only thing that we cannot see from the pictures is the connection for your 3 line cable, iare those lines correct! Did you take a multimeter and check continuity from the DBU board through your connector to the DBC board for the 5 connection lines? Do the same thing with the three lines that go to and from your Heng long board, are you getting 5 volts off your heng long board? Is that connetion correct to the Heng Long board? The IC controls everything but it is very robust and if it is seated correctly it is probably not that! If you do all these checks and all is well and you don't have another system to test and compare, then get a chip from David!

The Blitz

Appears R1 is correct and R4 incorrect.

The IC controls everything.

Thanks Blitz. Your advice is along the same lines as Davids. I'll give it a try and report back.

Tim

Cool, hope that baby is firing off some hits soon, what model are you installing it in, the T-34?

The Blitz[sm=shades_smile.gif]

Ok, I got a multi-meter today and did some investigating.


1) I measured the voltage across the LED + and - on the DBC and found 5 v on the multi-meter. 5V to Gnd was 5V, and LED+ to Gnd was 5V. All others were 0V. (I believe this means the board is sending power to the LEDs when it is not supposed to, but the LEDs do get brighter for a second when I move the left stick in config mode)

2) There is no continuity between the LED - pin and any other pins on the DBU. There is no visible short between the IR sensors and anything else. But I did find continuity between the LED- pin and the Gnd on the DBC. (Could be a short)

3) I measured continuity for the wires running from the DBC to the DBU and found them all to be good (ie no broken wires)

So with that reported I am waiting to hear back from David.

Blitz,

this DBC/U is being installed in my panzer 3. My T-34 has a broken ESC/RX cable which is preventing me from getting it to work, replacement coming next week.

My evening of RC Tank Trouble Shooting Hell.


David game me some more things to test for tonight. As I went to check things over before I powered up my tank, I noticed that a wire from both the ESC and RX had broken off at the solder points to the DBC. [:@]

I got so frusterated with resoldering these fricken wirers that I replaced them all with solid wire strands and hardwired them all (ie removed the connecter points on the ESC and RX). While doing so, the SIG connection point on the DBC had enough and broke off the circuit board! [:@] So I had to put in a jumper to another solder point on the board.

At this time my bottle of plastic glue that I did not secure spilt all over my work table. The tank escaped but it made one hell of a mess and I had a relapse in my vocabulary back to my Army days. Good thing the little one was already asleep.

Ok, with everything back together, I said a quick prayer and powered up. Yahoo everything works! Now I can begin to do some testing with the Multi-meter. But oh wait, I left the multi-meter on last night and the battery inside is now dead. And do you think I could find another AAA in the house???? No!

Time for a drink as the Electronic Gremlins win another round.[sm=cry_smile.gif]

Holy crap that sounds like one of my days....Tomorrow is always better....well have a drink on me!

The Blitz,

Will assembel the DBU/DBC for you with cabling and connectors see RCTankWars.com

When it comes to Heng longs I learned this part of modeling very quickly. Every single one of my Tanks gets blessed just prior to hitting the "on" button.