Tech II Railpower 1400- no throttle; how do I fix?

[richg1998]

printer65

where would I get a semiconductor for it?

 

 

Maybe Jameco Electronics, Mouser, Digi-Key, all online. Google them. You could Google the device number.

Rich

[Redvdub1]

I am confident that your problem is the TIP119 or T120 Darlington Transistor which is mounted onto a heat sink.  When it blows the supply puts out max voltage and you cannot control the speed.  The device is a discrete three-leaded device and it is easy to desolder and resolder in a new one.  Prices range from $0.49 (plus shipping) to around $9 per (free shipping)..  Used good ones go for around $30 per so I think it is worth fixing.  You do need a #10 security torx (Harbor Freight) and some soldering equipment (a solder sucker, 15W iron, solder, flux).  

kgill

I inhereted a nice layout with several controllers. One is the Tech II 1400. When I hook it up I get power and the loco will run but I cannot control the throttle level. The loco has one speed only and it cannot be adjusted.

I am using an old school non DCC set, so it is all DC.

I hate to buy a new new controller, this one seems like the best. Is it repaireable?

Keith

 

[printer65]

where would I get a semiconductor for it?

[richg1998]

I bought the proper tool bit many years ago and opened a similar one.

If you understand electronics, they are repairable depending on which part is defective.

Been too many years to remember what I did,. It might have been a semiconductor and I substituted. I have hacked circuit cards over the years.

Rich

[printer65]

I have the same transformer. It runs train & accessories for a couple of minutes and then quits. Wait 2-3 minutes comes back on. What's going on? Worth repairing?

[kgill]

Turns out it just done Blowed up. Had the hobby shop tech put a meter on it. Cant justify cost to repair so Ill use it to power my AC accessories instead.

Thanks for all the info.

Keith

[zstripe]

KAGILL,

I have had luck removing those screws with a fine point needle nose pliers, As far as the other problem, I agree with what Randy said about the Pot and or a transistor..

Cheers,

Frank

[Soo Line fan]

rrinker

Too many things could be wrong, from simply the potentiometer being shot to the main transistor being blown. Plus they used oddball security screws that prevent easy access to the inside so as to meet UL standards. And no wiring diagrams are available even if you did get inside.

                --Randy

 

The security screws use a T 10 anti tamper torx extended shank bit or a T 10 anti tamper torx screwdriver :

Last time I checked, MRC will not provide parts or a schematic.

It could be a loose wire or bad solder joint so it might be worth opening.

[rrinker]

 You do have the track connected to the terminals labeled "variable DC" right? Not the ones labeled "Fixed DC"

Too many things could be wrong, from simply the potentiometer being shot to the main transistor being blown. Plus they used oddball security screws that prevent easy access to the inside so as to meet UL standards. And no wiring diagrams are available even if you did get inside.

                --Randy

 

[kgill]

I inhereted a nice layout with several controllers. One is the Tech II 1400. When I hook it up I get power and the loco will run but I cannot control the throttle level. The loco has one speed only and it cannot be adjusted.

I am using an old school non DCC set, so it is all DC.

I hate to buy a new new controller, this one seems like the best. Is it repaireable?

Keith