mth-30-1159-1

Thank you John, Marty & George for your help. I did disconnect the harness before testing,and George is most likely right about the board . Hate to see a broken engine but will put this away for decoration. again thank you all

When you said the motor RUNS, exactly what wires were hooked to the motor?  It's not clear how you got a DC motor to RUN (actually spin vs. buzz) with transformer AC voltage applied to it.

Also, when you said the light works, exactly what wires were hooked up?  It's not clear how you got a 6V bulb to operate for more than a few seconds with transformer AC voltage applied to it.

In either case, as the guys are pointing out, IF the motor or light(s) were still hooked up to the PS2 board when you directly applied transformer AC voltage to the motor or light(s), you might have popped some components on the board.

Can you see a set of 3 wires red, yellow, black running from the PS2 board to a component screwed on to the frame/chassis?  If so and that component is accessible to probing with a voltmeter, there's one simple measurement I'd like you to try.

Interesting point Stan, wouldn't it be great if something simple was wrong?

there are 2 red & 1 black wire screwed to the frame .they  are wire nutted to red & black wires going to the 7 wire harness . there are 2 heavy yellow wires one going to a plug on the side of the frame and the other from a plug on the board to the motor.

stan

I found that board,

Measure the voltage on the DC scale between the center (black) connection and the right hand (yellow) connection.  You should have 5 volts DC with track power on.

This component which I believe is always screwed to the frame/chassis is a voltage regulator chip that supplies 5V DC to the electronics.  If there's no 5V DC, then nothing will work on the board and it will appear dead.  The input to this chip is a DC voltage which was converted from the variable AC track voltage.

As shown in the picture, you should be able to slide the white connector down a bit to expose the 3 legs of the component which will allow you to measure the voltages.  Using the DC voltage mode of your meter measure the two DC voltages shown with AC power applied to the track.  So the black lead of the meter goes to the metal tab, and the red lead of the meter goes to the chip leg as indicated.  Note that this chip is attached to the frame/chassis and you'd think that the metal attachment screw is connected to the metal tab but it is NOT.

IF for whatever reason you can't conveniently access the chip to measure the points indicated (with the engine powered on the track), you can first unscrew the chip from the chassis.  The chassis/frame acts as a heatsink to keep this part cool when operating, but for a few minutes it doesn't matter and can operate fine without being attached to the chassis/frame.

Again this is a long-shot but given the cost of repair/upgrade appears to be more than you paid for the entire set, I figure this is worth a few minutes of your time if the alternative to make this a paperweight.

I Have nothing on both legs of the chip

Sounds like either the board has no power or the main power diode(s) may have died.  Pretty unusual for something in storage, but who knows.

I think at this point the only way forward is have someone look at it before you toss in the towel.  Where are you located in PA, I'd take a look for free and let you know if it's really the board.  I'm in SE-PA

Since you previously confirmed track voltage AC is getting to the board (via the 7-pin connector) but there is no DC going to that regulator chip, then I concur with GRJ that some component failed on the smaller board of the two-board set.  This board (the one with the big coils wound on donuts) is difficult to work on due inaccessibility of key components.  As I understand it, even MTH service does not attempt to repair these boards and instead recommends the upgrade to PS2-3V boards as discussed earlier.

So if GRJ is willing to look at it, schedule an appointment right away! 

I'm in NE,PA and will gladly pay for repairs and shipping if they are worthwhile It's a old , cheap engine but I just hate to junk any loco. Thank you and the other fellows for your assistance .

Always worth a try, but it is probably a very long shot.  You don't need to send the whole engine, the board can be tested separately so that would save on shipping.  The other alternative is to install a basic reverse unit.  You would loose sounds and smoke, but you will have a running conventional engine.  G

Actually the bulbs will last a few minutes.  I have seen them under shorted FET conditions still work. They do get hot enough to melt plastic.  That is about 22VDC.  So a few seconds on lower AC voltage should be fine.  G

It's easy to convert these to conventional, and that would at least rescue the engine for conventional use.  Bulbs can be replaced with 18V bulbs.  They are correct, all I'd really need is the board set to test if it's working.  Of course, if it is working, then we'd still be stuck with the issue of what is really wrong.

Another option to consider would be to install an ERR board with TMCC capabilities.  They make two DC boards.  One with Cruise Control and one without.  This is their website address http://www.electricrr.com/.  This can be installed in about an hour with little trouble.  I'm not sure about how to connect the smoke unit if there is one and you would probably have to change out the headlamp to a higher voltage lamp. One other item is you would have to purchase a TMCC command base.  These can be found at reasonable prices on eBay or other such sources.  The command base will allow you to communicate with the ERR board through your DCS handheld and TIU.  This would give your engine remote control capabilities as it had with DCS and eliminate the raising and lowering of track voltage to control your engine.

EB

Since this is a PS/2 unit, the smoke has no on-board logic and is not capable of being connected to track voltage.

For the price of the engine, most of the upgrades to restore it's functionality are as much as the locomotive, so I'd probably either do the simple conventional conversion or perhaps sell it as a non-working unit and get another one.

While true, you need to consider if your trying to get back all the features besides just command control'  If you want sounds and synchronized smoke, the price points become the same.  So as John say, either you spend the money to restore, or you go the cheaper method.   G