PS2 Test fixture and Upgrade

The ps32 stacker drives regular bulbs I believe.

you need to add a resistor (300 ohm?)

I thought it was 470ohm or more. If you dont want insane brightness, just go straight to 1KOhm.

I would guess it matters what you want as well as what you're using (led model).

For an old era steam engine, probably want it dimmer? 570 OHM? 1000?

I use lesser ohm resistors because I'm usually doing more modern stuff with extra bright LEDs. 300ohm?

"Also, I have an old 3volt board that will run on the test fixture with a conventional hook up, but will not work in command.  When powered up under command it starts up immediately and will not add to the system.  Is there a reset that can be done, or is has the board lost command capability?"

I thought I read a post from GGG about this but I can't find it.

Does the engine play full shut down when power is removed?

Have you tried to reload the sound file?

I don't know of a processor test other than reloading. Someone posted about a hard reset years ago for techs only?

I have pulled the battery harness for a few seconds, and then reconnected. That board set was on the way out and finally failed on me.

I put resistors on the test fixture?

The test fixture is just a jig as far as I know about it. I am not a tech.

I just want to make sure that you know the difference in the available PS3 boards.

The PS3 diesel drives LED lights straight from the wires. The PS32 stacker drives regular MTH 6 volt bulbs for upgrading older steam.

So if the test jig has LEDs wired straight, and you connect the PS32 stacker, your overdriving the LEDs.

Now if the test jig has some sort of switch for selecting PS32 stacker vs. PS3, then no resistor would be needed.

I'm never sure what poster's level of training is. My memory is worse. So I apologize if this isn't helping you, or anything is incorrect.

I am not a tech! Just trying to reply for you.

As far as the resistors needed to run white LED's on the PS/2 or PS32 board outputs, the minimum safe resistor is around 150 ohms as the effective voltage output by the PS32 board or PS2 board PWM lighting outputs is 6V.  I use as my standard resistor for LED lighting in these situations a 220 ohm 1/4w resistor.  I've never lost an LED with that value.

The PS32 board connects directly to the PS/2 manual test set.  If the board is in "LaLa" land and the lighting FET is on steady, the bulbs will get 18 volts and indeed get really hot in a hurry!  What I do when firing up a board for the first time is set my transformer at 11-12 volts until I see the board is not running full bore, that  saves the test fixture lights.  I have been tempted to replace the bulbs with 12V bulbs that tolerate the higher voltage of a failing board better than the 6V ones.

I don't understand the comment about resistors in the lighting circuit, you'll have to explain that one to me.

@Engineer-Joe posted:

I don't know of a processor test other than reloading. Someone posted about a hard reset years ago for techs only?

The hard reset was only for the 5V PS/2 boards, and it was about 50/50, sometimes it did nothing or killed the board, other times it would work.  Since you were at the end of your rope anyway, it was worth a shot if the 5V board didn't come up any other way.

hi Charly  sent you an email check your email !

Alan

You need to make sure the Stacker board is seated correctly.  NO Resistors needed.  Something is wrong when bulb goes full bright except on some initial starts ups of the PS-32 because of the flash code.  I put a switch on my test set to kill bulbs when loading flash codes on PS-32.

The 3V may be a bad Power Supply board.  YOu can try swapping one in.  Otherwise a fault not repairable.   G

Good idea with the switch on the test set George, I was thinking of some way to protect the bulbs.

MTH had to reload the flash code before this last set of Kits sent out.  Apparently factory loaded the old code.  So there is a possibility that the board needs to be powered up to accept the new flash code.  The bright lights can occur on those initial changes, also when the stacker is not fully seated.  Lastly for the Panto flash they drive the ditch light signal for panto at a higher level so when loading it you will damage ditch lights unless you can turn them off.  Became a necessity for me because changing those bulbs is a pita.    G

Where did you put your switch for the bulbs?  I haven't actually looked, but I suspect all of them have one side on the PV and you can switch that?

@GGG posted:

You need to make sure the Stacker board is seated correctly.  NO Resistors needed.  Something is wrong when bulb goes full bright except on some initial starts ups of the PS-32 because of the flash code.  I put a switch on my test set to kill bulbs when loading flash codes on PS-32.

The 3V may be a bad Power Supply board.  YOu can try swapping one in.  Otherwise a fault not repairable.   G

Ok, which is the power supply board, top or bottom.  Or is it  best to start with a fresh kit.  Can I change the DSP code or is that a factory only function.

The Power Supply board on the 3V PS/2 is the top board.  They're still kicking around, so if that's bad, you can still get them.  The bottom processor board is unobtainium nowadays, if that's bad, the set is toast.

For PS/2, only the factory had the fixture to alter the DSP or FLASH code.

@Charly posted:

Just received a Steam Upgrade kit to install in a Northern

....it lit the front headlight LED so bright it began smoking.  .

@GGG posted:

You need to make sure the Stacker board is seated correctly.  NO Resistors needed.  Something is wrong when bulb goes full bright except on some initial starts ups of the PS-32 because of the flash code.  I put a switch on my test set to kill bulbs when loading flash codes on PS-32.

The 3V may be a bad Power Supply board.  YOu can try swapping one in.  Otherwise a fault not repairable.   G

@gunrunnerjohn posted:

The Power Supply board on the 3V PS/2 is the top board.  They're still kicking around, so if that's bad, you can still get them.  The bottom processor board is unobtainium nowadays, if that's bad, the set is toast.

For PS/2, only the factory had the fixture to alter the DSP or FLASH code.

@Charly posted:

Also, I have an old 3volt board

Something is going wrong here? Maybe it's just me.

The PS32 board drives regular bulbs, right?

on page 26

50as10709i_Steam_PS3 Upgrade Kit Manual_2018 COLOR.cdr (mthtrains.com)

The OP said it was an LED! right?

So is the correct board being described here??? (2 boards in OP post)

Yep, an LED will smoke unless you add a resistor.  My standard resistor for PS/2 or PS32 boards is 220 ohms 1/4W to use a white LED for lighting.

so why does a PS2 test fixture have a LED wired directly?

or does it already have a resistor on it?

That makes all my posts ridiculous here.

I always thought the MTH PS2 test fixture came with regular bulbs? That's where I messed up?

She miss spoke I assume about LED in the test fixture.  PS-2 test fixture is bulbs and smoking hot to melt the rubber grommet. An LED will never get hot, just burn out from over current.

PS-32 drives bulbs at 6V but if the board or code is off it drives at full voltage.

On the switch, yes I interrupt the PV to the bulbs.  Smoke and Markers still work with volume.  G

@GGG posted:

On the switch, yes I interrupt the PV to the bulbs.  Smoke and Markers still work with volume.  G

Sounds like a good idea for extending the longevity of the test-set bulbs.

OK, Thanks G.

Sorry for the confusion.  I misspoke calling the test fixture lights LED when they are not.  Though it was a rather convoluted thread, the answer was in it.  Thanks.  Went to a second board set and all is well.  So... if and when MTH is available for business I will have to return the kit for an exchange.

Thanks