[daschnoz]

I scored an MTH PRR K4s from eBay. PS/2. According to the eBay listing, it was never run. It's a 147th Bloomsburg Fair commemorative something or other from 2000. The guy I bought it from sent the "official" paper work, but not the original box. I would think that if it is so collectable that it has never been run, he would have the original box. But whatever, that's just me. I have no shelf queens. If I own it, it gets used, so I'm not worried about any collector value that it may have. I just want a K4s to pull my Madison passenger consist.

I put it on the tracks. Powered it up. Hit the start-up button.
POP!!

Smoke poured out from every crevasse that it could find around the boiler. I immediately removed it from the tracks, but I think it's too late.


Upon removing the shell, my suspicion was confirmed. It's a 5v board - well, it was a 5v board, now it's a dead board.


When these caps explode, do they usually take something else with them? What are the odds of me replacing the caps and this thing working perfectly?

- OR -

Should I just get a PS/3 board installed and spend the time building my layout?

 

[Tom_C]

Hmm. I think its worth replacing the caps. Are they shorted now, or open circuit? If I had the parts I would replace and see.

 

[seayakbill]

GRJ probably has the answer to that tech question. I would guess that it has been tried by someone since this is a common problem for older 5V PS-2 systems.

Bill

 

[Lehigh74]

The only K4s I found from 2000 catalogs are Railking and retailed in the $400-$430 range. You may have an uncataloged loco, but it’s probably also a Railking and in the same price/value range. Having someone install a PS3 board would probably cost $300+.

Before I bid on a loco on ebay, I check the MTH site to see if it has a 3V or 5V board.

 

[gunrunnerjohn]

If you can reach them, you might try replacing the caps. OTOH, it's a pretty low probability that it'll actually fix it.

I think you'll find that the largest cap is the one that blew.

 

[Big Ed]

I scored an MTH PRR K4s from eBay.

I put it on the tracks. Powered it up. Hit the start-up button.
POP!!

Smoke poured out from every crevasse that it could find around the boiler. I immediately removed it from the tracks, but I think it's too late.

Should have had the video camera going.

New but no box, how long have you had it?
I suspect something may have been wrong with it, the reason it was being sold.
Did you contact the seller?

 

[Lehigh74]

I have to agree with Ed. You did nothing to it except put it on the track and power it up. It should be returned. If you try to repair it, you can not return it.

 

[gunrunnerjohn]

I'll sing with the chorus, send it back.

 

[Volphin]

The only K4s I found from 2000 catalogs are Railking and retailed in the $400-$430 range. You may have an uncataloged loco, but it’s probably also a Railking and in the same price/value range. Having someone install a PS3 board would probably cost $300+.

Before I bid on a loco on ebay, I check the MTH site to see if it has a 3V or 5V board.

Where on the MTH site can you do that Bob?

 

[Lehigh74]

Where on the MTH site can you do that Bob?

Go to the page for the loco and click on the support tab. The manual is the second pick from the right. Sometimes newer stuff has that tab greyed out, but I think there will be an operator’s manual there for most PS2 stuff. Page through the manual till you find the battery section. If it has an 8.4V battery, it has a 5V board.

 

[Maxum]

Before I bid on a loco on ebay, I check the MTH site to see if it has a 3V or 5V board.

That's exactly what I do. I recently bought a MTH Consolidated PS2 at a train show. I made sure it had a 3v board before I made an offer.

 

[daschnoz]

It's a good looking loco and I really want a K4, so I'll keep it (plus the seller does not accept returns). I'm not much of a collector, but for some reason having a unique, uncataloged model appeals to me.

GRJ
Yup, it has the notorious 330uF/35v Wincap, and it's bulged. I'm going to try to fix it.

How do I get the 2 boards apart to get the soldering pen on the pads? Do I need to desolder the connection header (that's going to suck)? If I can't get to them easily, I will try to disassemble the cap (it already started that for me) and connect to the remaining leads.

Not having a schematic for the circuit, and given the size of the cap, I think it's safe to assume that this is the 1st filter cap off the rectifier, before a voltage regulator. I don't have a 330uF, but I do have a 470uF. I'm going to try that one with some alligator clip leads and see if this mess is salvageable. If not, I'll have a PS/3 kit installed.


I think in the future, I will stay away from PS/2 on eBay.

 

[Tom_C]

It looks like there might be a connector just to the left of the arrow in the picture John posted. If not, then yeah, it's probably a matter of desoldering the 2nd board. If you have solderwick or a solder bulb/sucker it shouldn't be too hard, but that's easy for me to say

 

[Lehigh74]

Sounds like you have made up your mind up to fix it, but even if the seller does “not accept returns”, you can still return it if it is not as described. That is ebay policy. Seems to me if it was described as “never run”, that implies that it should run. Or at least it shouldn’t mean that it WILL NEVER RUN.

Even if you repair it, I would still contact the seller. If he refuses to give you at least a sizable partial refund, you should give him an appropriate review.

 

[gunrunnerjohn]

First off, I agree with Bob, it doesn't matter if the seller doesn't accept returns, if the item is not as described, they have no choice.

If you decide to attempt the repair, DO NOT TRY TO DESOLDER THE TWO BOARDS TO SEPARATE THEM! That is an exercise almost sure to fail! Been there, done that, burned the T-Shirt!

The pins are apparently press fit before they're soldered, it is basically impossible to get them apart without damaging one or both boards.

I replace the 330uf 35V cap by just propping the two boards slightly apart with a small block, and then reaching in with a small soldering iron to to the replacement.

Truthfully, this is not that likely to actually fix it, you will most likely need to obtain a PS32 board with 5V connectors to repair this locomotive. If you decide to go that route, drop me a line, I'll get you a discount off the MTH MSRP on the board and heatsink kit you'll need.

 

[daschnoz]

Well it almost works. It fires up and sits on the track making its idle noises. But, there is zero response to input from the remote. Oh well.

 

[gunrunnerjohn]

Sounds like it's starting up in conventional mode. I have it's mate in my junk board box.