P
Try reverse engineering. undo the last mod ( maybe the fan hook-up) and see if that makes a difference.

Jim

Iwas afraid someone would say that!

The fan wont be so easy to get out of the equation (Iused rccommand's method and taking it out would be a nightmare - or getting it back in).

Are there any standard diagnostics that can be run - with a multimeter or whatever?

p

The fan should run without help. Possibly the problem. Clip one fan lead leaving room for heat shrink and re-soldering, try to start the tank. If the fan is not the issue, re-solder.

OK..... I disconected the fan...no joy.

Disconnected everything except the TX board, power, volume control and speaker. Nothing happening.

I am assuming that the miniumum one can expect is the speaker start up sound?

There are no other electronic modes. Fuses on the motor leads and thats it.

And to be fair.....this is the first time Ive ever switched th ething on. IT has never been run before.

There is no smoker attached either as Idont want that.

Id be willing to buy a new board(s)but this tank has sucked up alot of time and money and throwing good money after bad couldnt be smart....

Id have to buy the whole lot and thats anywhere between 30 and 60 euro with no guarantees theyd work either?

Is it possible to check that signals are coming out of the TXboard?

p

Slight update....there is a vague hiss noise from the speaker but it is in no way responding, in either volume or tone, to anything on the transmitter i.e. its there all th etime

p

When I first received my Bulldog, I had the same symptoms. The transmitter crystal was the culprit. Slightly bend the crystal "legs" to be sure you are getting good contact. Do you have another transmitter? One you can borrow? The light is on on the transmitter?

I have 25mm 12v, it's actually better to run a 12v for cooling the rx18 then a 5v, you dont want a cooling fan to fail, I wired mine up so that anytime I turn the main power on the fan is running, my fan starts on it's on , I bought it from rccommand, fits perfect, cools alot.

HI folks

The transmitter led is on and steady red, blinking headlights and hiss from speaker. I have no access to other HL transmitter/crystals (except the spare ones).

As I genuinely have spent all I can on this tank (too much already), I need to try and figure out what is the most probable fail point. As having a 400 Euro pile of Tiger shaped plastic in the garage is a horrible feeling.....

For those who have blown an RX18 board....did the transmitter light go green even with the blown board? i.e. does the Tx light go green if the TX board is working and the RX18 is not?

If I open the TX hand unit...is it with the screws at the front or back and what are the chances of it not going back together? What am I looking for in there?

In terms of probabilities.....which component of the three (RX, TX and TX handheld) is most likely to be knackered?

Is trying two pairs of crystals enough?

Is there anything else I am missing - all batteries charged etc. I was under the assumption the tank could run without the turret? So I have never connected that.

Anyone else ever successfully diagnosed what was wrong with a tank without just having gone out and bought parts until the thing worked?

p

Iposter, do you have another battery?<div></div><div>If your 12v PC fan needs a nudge to get going, sounds like your not getting enough power. I have hooked up several different 12v PC fans and the only times that happened was when the batt was near the low point....or the fan was caught on something.</div><div></div><div>The blinking lights have happened to me before with no ability to start the tank because the batt was low. Forgive me if you've tried this already with a different battery.

Also, your transmitter light goes green? hmmmm, that's different.</div>

Hi BiggTony

I did get another battery and with a fresh charge the fan did start. Im a bit worried about that as the first battery was at about 70% Ireckon....at which point the fan wouldnt spin.

That surely has implications (if I could get the tank running)for the safety of an RX18 with a fan mounted on the main circuit?

I have actually a 9v circuit in the tank for driving the fan under the engine deck (with its own switch)and reckon Imight either set up a circuit for the RX18 fan in a similar way or stick the RX fan on the circuit for the engine deck fan.


On another thread a poster called GeirMagne mentions measuring voltages on the "pcb's".....does anyone know what these voltages should be ?

This is the thread:

http://www.rcuniverse.com/forum/m_95...tm.htm#9560455

He had the same problem as me but did not post if or how he resolved it..... (there should be an obligation on people to eventually report how problems were solved!).

p

Sorry for all th eposts.....

Whats the difference between 01, 02, 03.....17 crystal sets?

I see them on rctank.de and the 01...03 sets are cheaper than later numbers? Anyone know and which numbers are most reliable?

Sorry again....

p

Nothing to be sorry about, you have a tank and want to see it run. We all have been in this position to vering degrees at one point or another( I mixed up the wires in my Mato Sherman and almost fried the board ( it actually did smoke) The wife said if I don't get it running, that was going to be my last tank. Thank god for the help here, I got the wires corrected and it started).
Someond had mentioned on bending the crystal connecting legs a bit to ensure good contact. Have you tried this already?

Jim

Hi 1stSgt

I did indeed try the leg bending thing but to no avail. Ibent them until it required some serious flexing to get them in (at least on the TX board...theres not much room for much bending on the transmitter.).

Iordered new crystals yesterday and a new TXboard but Iswear to God thats the last money Ifeed to this thing. I would have been better off buying two tigers to start with on the basis that the bits would have made one working model...

Nonetheless.....onwards and upwards!

p

<span style="font-family: 'Lucida Sans'; font-size: medium; "><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: rgb(255, 255, 255); font-family: Arial; font-size: 12px; background-position: initial initial; background-repeat: initial initial; ">Iposter,<div></div><div>Sorry you've been having some issues with your tank! I really feel for ya. I thought I had issues in the beginning, but I hate to say this but,.......they always say "When you think your problems are bad, there's always someone else out there who's had it worse than you." and your that guy, lol.</div><div></div><div>So you've started from the ground up and no communication from the transmitter to thereceiverto start the tank up. Even if you only have the motors hooked up to the RX18 board andreceiverto the control board? Both wires are securely connected from the RX18 board to thereceiver? Have you hooked up a volt meter from the RX18 board to thereceiver? I can'trememberthe voltage reading I got from the wire that connects to thereceiver, but there is asubstantialcurrent reading if I recall.

Edit: I just checked the receiver board using the soldered joints where the three wires connect to thereceiver. With a fully charged battery, the supplied voltage was a constant 7.6v from the positive wire (blue) and negative wire (Red) and constant voltage with the Black and Red wire was a constant 3.2v. This was with the tank in idle mode.

I started to freak out for a bit, since my tank is still being worked on, I have a loose speaker sitting next to the board. (I know, that's asking for trouble.) The tank wouldn't turn on! It just stayed blinking. I thought,"Oh, brother....here we go!" lol The speaker sitting right next to it was causing interference and viola! It turned on, lol.</div></div></span>

Hi BIggTOny

Its my wallet that deserves sympathy....I'll survive, it might not!

<div>Thats correct..

Ihavent tried it with just th emotors....Iwas using the speaker as a "default" status (Iassumed that it would less risky....but Icould be wrong).


Im now getting confused.....Ionly have one wire from the RXboard to the receiver? Its a three strand wire....Icannot find any other one?


Thats what Im after.....as in th etype of info Ineed.

Nice one! If there is no voltage there (across the wires) does that mean the RX18 is busted (and possibly the TXboard)? If there is a voltage does that mean the RXis OK and the TXis busted?

Oh crikey.......I need to move the three or four spare speakers Ihave from the side of the tank.....

p</div>

Hi folks

Today Igot two more crystal pairs and a new TXboard. Neither of which made any difference.

After significant and long term investment in this tiger I am in the position where Ican either afford an RXboard or a new transmitter.

The only things connected to the RXboard are the battery, the TX board with antennae, and a speaker.

The transmitter is switched on , then the tank, and the red light on the transmitter stays on.

If the tank is swictched on first, same thing.

Iopened the transmitter and there is nothing obvious loose (although Ican only see the back of the board in there).

There is no smoke, no burn marks, no obvious loose bits on the RXboard.

Is there anything at all obvious that Iam missing here?

Please.....?

p

Hey P!<div>
</div><div>In the replied post to my previous.....did you say that you weren't getting voltage to the receiver board? Did you check? </div><div>
</div><div>If you didn't find power going to the receiver board....then that's your problem! That's how the receiver communicates to the control board, variable voltage is relayed to the control board. If your getting none supplied to it.....how does the receiver communicate back? </div>

HI BIggTOny

Sorry about that.....I was actually getting voltage to the receiver board. Imeasured across two contacts on the TXside of the cable from the RXboard and got a voltage (cannot rememeber what it was but it was less than 7.2v).

Ishould have mentioned that......

p

Just checked again.....its 7.8v on the TXside between the yellow and greenish cable.

So voltage is getting to the TXboard.

tried a different antannae as well just now but no luck there....

Of the two....which is most likely to be busted....RXor transmitter unit (ie. handheld unit)?

p