Changing out a bad HL board (something to think about )

[BIGMIG]

I'm posting this under the heading "what ever It's worth".I have seen on many occassions where guys have burned up a board ( 13 & 14 boards---Haven't seen the new 18 board yet) and just replace the big board and re-use the receiver board.If you know why the big board got fried (a chunk of wood stuck in the track,trying to climb Mt.Everest on a 100 degree day,or the next door neighbor kid tries to drive it through a wall--ect--ect ) you may get away with just replacing the big board.
But what I wanted to caution you on is sometimes these boards just have a meltdown for no apparent reason.(this situation is where you are rolling the dice trying to re-use the old receiver board).
I had this happen to me where I had a meltdown on a tank that had only been slightly tested in the house on a smooth floor and the following day just turned on the tank and it started smoking and burnt up the big board for no reason.
For those of you who know "Darkith" on RCU he is one of few people who realy know their stuff when it comes to these boards.(there are a few others).I had a discussion with him on his thoughts on why this may have happened.He seemed to think that ever so offten the receiver gets confused for some reason and trys to send conflicting signals to the big board and the result is a melt down.That tended to make a lot of sense to me and I allways figured it would not be very smart to try to reuse a reciever
under those conditions,much more senseable to replace them both and not take a chance.Just something to think about.-----

                                BIGMIG 

[tiger205]

hi larry
        i'd not really thought of this before (how many of us have) in the past like most people when i've burned the main control board i've just replaced that alone, and with my daughter having 2 HL equiped tanks, this is something usefull to know

                Tony

[BIGMIG]

Hi Tony,
  This is just an educated guess and a guy may get away with it and not have any problems,but i look at it like if it did this wonce it may do it again.

                    Larry 

[tiger205]

hi larry
          what you say does make sense, before i changed to elmod i blew 4 boards in my Tiger, i know the weight had a part to play in this, but it could well of been the reciever board that helped them on thier way,

            Tony

[NigelDerEnglander]

Hi folks,

I sort of want to agree with you on this, but my electronics knowledge tells me this is an old wives tale!

I too have experienced burnt out boards, and the classic "tank stops and gun fires continuously" problem. Not "fail safe", but "fail dangerous"!

What we have to realise is that the receiver board is "dumb". It cannot make up dodgy signals, there is no digital electronics in it, it is purely analogue. What is more likely is that the control board is defective, or the transmitter is sending out a weak, badly modulated, or distorted signal which is misinterpreted by the control board. Or the control board is prone to misinterpretation of the control signals. The processors on the control board appear to use internal oscillators, rather than external crystal oscillators. consequently they will be prone to timing problems.

I work with radio transceivers and took a receiver board to my expert colleagues who tuned it up for maximum sensitivity. Using this tuned-up receiver I still got the "tank stops and gun fires continuously" problem - much to my chagrin!

Any problems like this are, I'm afraid, due to the transmitter box, or the control board.

Well, that's my opinion.....

Nige

[BIGMIG]

Hello Nige,
    Thanks for explaining this on the receiver board.Was tempted to remove this because I didn't want to post something where I was guessing about this board not knowing the facts on it's function,but it may serve a purpose
by leaving it here to answer the question others may have had on it also.

                    BIGMIG 

[panzerfahrer]

Has anyone considered the possibility of outside interference, we stopped using 27meg radios for r/c flying a long time ago for this reason, CB`s, side-band transceivers (which are worse) plus all the other remote r/c toys and gadgets that are filling the airways.