Ripley's TnA (Talk n Action) Repair Thread

[ripley802]

Grrrr.. so I think this is my issue..

What I have learned so far as mentioned is there are both NPN and PNP transistors amongst others both those are common ones. Well apparently there are also some differences in the numbering on them.

For example, when I read the number off the one I needed I thought it was 8050. So I searched and found S8050 as a common type and purchased the lot in the previous post. Well after messing with a James today for 2-4hrs (I lost track of time)... I discovered that the number was 8050S. Those seem to be less common and could possibly be a U.K. thing as all that I have seen with this are U.K. James.

So I did find a listing on eBay for what looks to be 8050S but they are in China so it will be a bit before I get them..

I did find that some of the others from the lot I bought seem to work, but I would rather use the needed one if possible.

[Super]

Nose to grindstone...

Great work ripley, yes sxxxx are different from xxxxs but don't ask me how! they will have different characteristics,

Transistors do go bad so your doing the right thing changing components until you find the damaged one, do you have a multimeter? Some have a transistor tester on them,

Also when your soldering do you use a solder pump? It's great for getting rid of excess solder on a joint or removing bad solder, With solder you can get dry joints which aren't conductive although they physically look good and are connected.


Keep up the good work,

[ripley802]

Thanks Tramp. Yeah I have a cheap multimeter but it does have the setting on it to check diodes/transistors. I had been checking and seeing weird results then found the part number difference.

I am hopeful the ones I ordered will solve the mystery.

Yeah the solder pump has been a life saver. As I am sure you are aware these tiny circuits can be a pain sometimes but having a clear pin hole to insert the new component is a must and the solder pump has solved my issues there. . I am not sure how I did much of anything without it before..

One thing I did notice, on a Gordon that was running pretty well (speed wise) I checked the voltage to the motor and it was about 1.9x almost 2v (the circuit is 3xAA) so 4.5v total. When I checked the James with slowness issues it was around 1.7x volts. So there is something in there it seems causing the voltage drop, but so far I have not isolated it. Once I get the new transistors, I will test that with a new capacitor and see if there is any change.

[ripley802]

I received my new replacement transistors. The good news is they are the correct ones and work fine as a replacement. The bad news is, they did not help with the speed issues.

I will keep looking into this and see what I can find but for now it seems if they are slow, then unfortunately there is not a lot to be done. I may look into some more replacement motors to see if that may be a fix. The ones I have seem to be hit and miss on if they work, are slow or are loud.

[Super]

Strange

Just Curious has anybody noticed how sometimes people fiddle with them and do dumb things like glue the wires to the top of the inside of the shell so you can't get it off?

[ripley802]

I have not seen that but have seen some odd stuff. It could be the adhesive from the tape although that comes off pretty easily.

also Ripley do you know what'd fix the gear problem on every engine once and for all?
Metal Gears.

[ripley802]

Possibly metal gears but they may be very loud. Likely though just some better quality gears. It seems like most all the failed ones are the white plastic, but the replacements are note of a clear plastic which seems more durable.