MTH PS2 Board Dead? How do you test it?

Hello guys,

Got a similar issue with a MTH Blue Comet PS2 5v 2002.  Put the engine on a test track with new tiu and nothing.  Slight hum from tender.  Previously the engine was only run in conventional mode.  I know the TIU is working with the wifi, because I loaded two other diesels, and no problems.  They were PS2 3v versions.  Is it possible the board fried because it got the full 18 volts of DCS this time?  Could the voltage regulator be the problem and how could I test it ? 

Any help is appreciated

BTW, the wifi and TIU setup is great.  Been waiting on this for the last 2 years.  First time I got a TIU and now this happens

5V boards are susceptible to failure.  If they are dead they can be replaced with PS-2 3V with 5V connectors or the new PS-32 board.  G

The new PS32 board is the way to go.  Send your board to a MTH tech that has a board tester.  Those boards are all on borrowed time.

MR_P posted:

...  Previously the engine was only run in conventional mode ...

Is it possible the board fried because it got the full 18 volts of DCS this time?  Could the voltage regulator be the problem and how could I test it ? 

Any help is appreciated

Does it no longer work in conventional mode?  Do you hear the relay click (listen to you working PS2 diesels if you don't know what the relay click sounds like) when you initially apply power?

The board did NOT fry simply because you applied 18V when previously it was successfully running conventional.

The voltage regulator can be tested with a meter in DC Volts mode.  You can slide back the connector just a bit to expose the 3 leads while still making contact.  The metal tab is connected to the middle pin and is "-".   If you are careful not to short anything, with 18VAC applied to the track the left lead (with component markings upright) should read around 25V DC or so.  The other lead should read 5V DC exactly.  It is very unlikely the voltage regulator is the problem. 

More likely you will indeed read 5V on the voltage regulator but the board does nothing (no relay click, no nothing).  At that point there are only a few guys (GGG being one) that know enough to troubleshoot further or just throw in the towel and explore the other suggested options (PS32 or whatever).

If it doesn't work in any mode, it's likely dead.  Most of the 5V boards I've had that truly died did so in two different states.  A direct short that trips the breaker immediately.  Open circuit where they draw no current at all.

I think GGG will probably tell you the same thing, the chances of recovering a truly dead 5V board are not all that great.

It is sad to see so many of these boards crashing left and right.  What disturbs me is when someone takes a good board and a close to dead 15-18 year old battery and tries to start the engine.   I am very happy MTH has come out with the PS32 boards to be a great fix for 5 volt boards.

Thanks guys for the words of encouragement,  jk. I talked to GGG and gave him the Loco to check it out. Nice guy and a good train show at the vtc meet. Everyone was nice,  nice items too.

Let us know how it comes out.

MR_P posted:

Thanks guys for the words of encouragement,  jk. I talked to GGG and gave him the Loco to check it out. Nice guy and a good train show at the vtc meet. Everyone was nice,  nice items too.

It's in good hands.  GGG fixed the engine I reported at the start of this thread in 2014.  He also has another engine of mine right now in the works.

Ron

Has anyone ever found the cause or what component fails on the 5 volt board ? 

GGG says board is dead

MR_P posted:

GGG says board is dead

Look at the positive side... You're not replacing a failed component, your getting an upgrade. 

Have Fun!   Soon.

Ron

Dave Zucal posted:

Has anyone ever found the cause or what component fails on the 5 volt board ? 

Opinions vary. What you see frequently is the power supply components have died. I've seen enough of them with a particular cap leaking and/or swelled to think that might be one cause.

MR_P posted:

GGG says board is dead

 I'm not that surprised, not many of them come back from being truly dead.

I have seen the cap fail, but replacing it has only worked in 2 of XX or XXX boards.  I have seen a diode pair meant to make DC for the Circuit board fail.  Very hard to get to, I have seen a large FET fail that I am not quite sure what it does.  I have seen nothing obvious, so I assume the processor just stopped working.

I have seen total beat up an non maintained engines with 5V boards in that still work fine.  Really seems to be a random occurrence though some engine seem to fail more regularly like the FEF.

Mikes board was a newer version, nice an clean, and no obvious signs, but no relay click.   G

I think replacing that cap is too late after the failure.  I've replaced a couple in working boards that came in for repair when I observed they were leaking or swelled.  I didn't get the units back for any failures, but it's obviously too small a sample to make any real determination.  I figure if I see that cap swelling, and I can reach it, no reason not to replace it.  FWIW, the brand of the cap that has universally been failing that I've seen is WINCAP, the 330uf cap at the edge of the top board.

Update, gave the comet to GGG to upgrade to the ps32 board.  Works very well !

Thanks GGG !!! 

Guys, those 5 volt  boards are old.  Normally, none of us would expect the computer we purchased in 2002 to still be working properly.  The PS32 board is the hot setup.   I feel that MTH has done a good thing with those PS32 boards.  Instead of being pushed into buying a new engine, for reasonable money you can get your engine operating again.  I had the PS32 boards for testing early on before they were released and they are still operating great today.

Marty, I have test equipment from the 70's on my workbench, works as good as the day it was new.   Some electronics lasts longer than 15 years.