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Hi guys,

i have had the same problem with a pug 307

Do you all run on scaley tracks?
And does anyone know what voltage the SCX system runs at, because i am sure i read something about that somewhere?
Something about the 16v being too much for the scx's light board? Not 100% sure though.

 

[zipp]

If it helps Rich, i will get the camera inside the pug, once i get home.

I would love to get to the bottom of this, as i love the scx cars, but have always been put off by this unresolved problem.

I believe (as Kevin Vonk) that the voltage is the issue.

Am i right in thinking that the scaley wall warts put out 16v max?
I will see if i can find out what the SCX system put out.

After a quick scout around, i found this on the SCX site..click Products, Accessories, and then the small down arrow near the throttle, until you get the ps.
It says that the wall wart is 14v.
Would 2v really be enough to make a difference?

 

[zipp]

a pic of the front board:

and the rear, although there is not much to see, and probably not much help.

QUOTE The strange thing is, sometimes they come back on or flicker only at full throttle?Pete, that is exactly the same problem i have with the pug. The rear lights are fine. Nice and bright and constant. This is why i believe it is something on the front board.

It would be great to get to the bottom of this problem, as i think the SCX cars are awesome apart from this.
I wonder if there is an easy fix/upgrade, to be found? I sure hope so.
Looking back through the "Master Class" and the "Cars" forums, this SCX issue has been mentioned a few times, with no definitive conclusion.

 

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Hey rich, i have tried to get some info for you.

I am not sure if i have done this right, but i will explain what i have done, and what readings i got.

I set my meter to V 20, and then put the red+ connection to "0" in the pic.

I then put the black- connection to "1" and had full throttle on the car. The meter showed 2.80v.

The same set up for "2" showed 10.51v,
and at point "3", 0.98v

Now the bulb on the left was very bright, but the bulb on the right only just illuminated, even at full throttle.
But i think my board is defective?
Not sure if this is what you wanted Rich? Hope it makes sense to you.

Would be interested to hear from someone with a new, good light board, and the contrasting results.

 

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Hi Rich,

with the black lead on the opposite strip, and the red connector at:
1, we get 12.14v
2= 4.23v
3= 14.08v

Now this makes even a little sense to me.

(i think)

Does this mean that 14.08v is going into the little black thing,
and then the left bulb is getting the 12.14v, and the right bulb only 4.23v?

I take it this little black thingy should be kicking out equal v, at points 1 & 2? and therefore my little black thingy is broken?

I am getting all technical.

 

[zipp]

QUOTE Will be interesting to see the other two readings.Rich, with the black probe on the neg side, touching the outer legs with the red pen,
LH led= 3.95v
RH led= 5.45v

and with the red probe on the pos strip, touching the outer legs of the led's with the black probe,
LH led= 11.24v and smoke from the LH 680 thingy.

(resistor)?
RH led= 9.67v

Rob,
I tried the same thing, by putting direct current to the led's. Unfortunately, (as i am an electronic moron) i put 13.8v across one...POOFF

So led replaced and connections good.

Hey 911,
Do you have a meter to do the readings Rich is requesting? I am pretty sure my circuit is already compromised, so if you have a good board, you maybe able to provide some essential info to those that understand it.

 

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Rich,

QUOTE Have we confirmed what voltage a standard SCX set runs at?I think it's 14v, but it would be nice if someone with an SCX set could confirm.

QUOTE So do all SCX cars have this style of light board or is it just some cars?Not sure, but a lot of folks with similar problems.

Is the purpose of the weak component, to provide a constant brightness in the led's, irrespective of the throttle position?

QUOTE Solution will be to use a beefier device or do as Col suggests and replace with a simple series resistor.Would be good to see some pix of the resistor fix.
If you could use the pic of the board i have posted, and indicate where the resistor should go, and what value, please, that would prove useful.

And i suppose the best fix would be to find a compatible upgrade for the transistor. Any takers?

I will take the Audi A4 and a Aston.

scale's choice

 

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Hey Rich, Thanx a lot

We have done the mod you suggest to a new car, and have completed over 20 laps, and shock

horror

the lights still work. Normally scx lights give up the ghost after about 3 laps.

A pic of how we followed your instructions:
A single cut, and copper strip bent out of the way, resistor soldered, bridging the gap.

Not sure if that resistor is correct, but it works.

The lights are slightly dimmer at low throttle, but only very slightly. And if that means they are gonna work for longer, then that is a fair trade.

Nice on Rich, thanx for taking the time

If this is the solution, then it is a well worth while 5 min fix.

We will keep you posted as to any developments.

 

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Nice one Rob,
Yes pix would be great please. I could then think about fixing my pug.

QUOTE The LEDs weren't expensive, £4.45 inc post for 10 LEDs and resistors from an ebay seller.If you have a spare pair Rob, i would gladly PAInPAL you an amicable ammount? If you don't have spares, would you be so kind as to provide a linky, to the seller please.

Another 30 laps with the Fiat, and still working fine.

Cheers Rich.

 

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Oh right, the whole front board is gone!! Super job.

Cheers for the pix, and linky, Rob.

I think i will be able to manage that.

Nice one Rob.

QUOTE you should consider putting a series diode with the 470 ohmRich, Do you know where i might find these on the net, please? Any linkys?

 

[zipp]

found these one's, are they any good??
If so, How much would the resistor value want to be with these in series?

edit: I see Rich listed this model in the last post.

sorry.
My resistor Q still stands though.

If anyone wants a few, just drop me a PM. I don't think i will need 100

Rob, i will fire some your way, once i receive them.