Radio Shack ZipZap shorted - toasted
Jim
Does anyone have any schematics, or troubleshooting info for ZipZap?
Can the NiMH be 'broken' by shorting + and -?
I opened the plastic cover and peeked under the circuit board and
*knew* it was going to be trouble. There's a fine fine enameled coil
wire (for the steering) that just kinda loops around things like
capacitors and resistors to 'shorten' it somewhat neatly and orderly
so they can close the case. Silly wire really just floats and flops
around. Measured later and is appx AWG 38-40.
I was *trying* to be very careful getting the wires free but there was
a quick ffzzzzttt and that was it. Might have gotten hung up on
anything really, battery, resistor lead, anything , there's all sorts
of metal in there.
Charger light stays green for several minutes.
Battery shows 0.85V whether plugged into charger or not.
There're four wires coming from the steering coils. The two that are
commoned and connected to battery V+ have about half an inch, from the
soldered point, of blackish looking discoloration that sure doesn't
look normal. I can't get a reliable resistance reading off the coils,
have only two hands. :)
This thing is just a 'problem waiting to happen' anyway with those
wires flopping around. No -way- can it last more than a few months of
average use before it toasts itself involuntarily.
TIA Have a :) day!
--
jim barchuk
j...@jbarchuk.com
Me
I had a similar car. The "battery" is actually a capacitor. It is possible
that you fried the capacitor, but prob. not. That black spot is probably
where your problem is. Where exactly is that spot? Is it on top of or on
a contact of a component? If so, that component is gone probably.
Jim
I saw the threads about the batacitortor idea. This is clearly a
battery:
"GP" (boldface logo] Ni-MH Battery
10AAAHR (looks like a part number)
1.2V 100mAh
Gold Peak http://www.gpbatteries.com doesn't show any part numbers
that match exactly but others are very similar so I'm sure that's it.
The blackish is on the wires themselves. There're four wires going to
the two steering coils. Two wires are commoned and then each coil gets
one separate wire.
Buuuuuuuut now I'm more inclined to think that that blackish is
-original- to mark the coil -polarity-! Looking under a loupe it's not
the typical 'charred/lumpy' looking effect really. Where some of it
seems to have rubbed off the enamel underneath looks very clean.
I also managed to get a better reading off the coils and they're both
16 ohm. (That's why someone mentioned they get far more run time when
they did a lot less steering.)
I think that's not the problem.
Further clue:
As I mentioned the battery showed 0.85V in circuit. Pried it out and
it shows 1.14 and spins up the motor just fine (out of chassis.)
Found more signs that this as embly is a disaster waiting to happen.
Found tiny microglobs of solder from hand soldering of wires. Plus
flux, meaning it was -not- cleaned afterwards.
Found a 'streak' of solder on the motor filter cap, just waiting to
fall off and short out something else.
No, none of this is from an exploded solder connection from a short.
The streak is -right- next to a hand soldered connection (motor frame
gnd) and points straight -downward- toward the PCB, not away as it
should have landed if something exploded. It got there when the
assembler reached -towards- the PCB and wiped the tip of the iron
against the cap.
Oh well. I might probe things further and trace out some of the
circuit.
Tnx. Have a :) day!
jb
--
jim barchuk
j...@jbarchuk.com
Chris
>I had a similar car. The "battery" is actually a capacitor. It is possible
>that you fried the capacitor, but prob. not. That black spot is probably
>where your problem is. Where exactly is that spot? Is it on top of or on
>a contact of a component? If so, that component is gone probably.
I have two "ZipZaps", and the battery is NiMH in both. Definitely not a
capacitor. It says right on the can "NiMH 280mAH" or something similar. I
also broke one of tiny steering magnet wires, and managed to strip the ends
and solder it back together.
Chris