PS1 Smoke Unit Quit

The PS1 smoke unit just receives track power and runs.  The one in the GS-4 that I'm currently upgrading was just wired directly to the track pickups through the smoke switch, no control from the PS/1 electronics.

You can unplug the input power connector (NOT the fan connector) and put 12 VAC from a transformer directly on the smoke unit.  If it doesn't work at that point, I'd suspect the regulator on the smoke unit board, or perhaps one of the other components.

Charly,  There is a small Full Bridge rectifier on the board.  Small square about 3/8".  It takes AC input and makes DC.  If you trace the wires feeding the smoke unit that is the AC in.  The other 2 pins on the rectifier are + and negative DC out.  Measure the output.  I imagine it has no output.  That prevents the fan motor regulator and the heating elements from getting an input.  That can be removed and replace.  The PS-1 kit has those regulators in.  I have some and can mail you one if you isolate that as the problem.  G

Thanks GGG, will check it out and let you know. 

Hello again...

I am finally taking time to poke around in the little guy and try to figure out his ailment.

What setting do I use on my meter and where do I put the probes?

Cheryl, in your last photo it looks like the yellow and white wires to the fan motor go to the far left connector at the edge of the board?  The following closeup of a PS1 smoke board (albeit no smoke chamber/fan) shows a different location for where the fan plugs in.

Stan,

Yup, got it backwards.  Now we have smoke, fan works off unit, but not on.  No power to the motor connection.  Figure a transistor bit the dust, thanks for the input. 

Charly, measure the output of the 2 pins that the smoke unit plugs into.  Should read 5VDC.  I am surprised the fan motor ran in the AC input position.  AC on the output of the regulator could have damaged it.   G

Josey,  That is the Full Wave Bridge rectifier that converts the incoming AC to DC.  G

Josey, I couldn't find a similar "deal" on eBay for the DF04 but auction # 120925432518 gets you a suitable part (has higher voltage rating which is fine) qty 5 for $2 with free shipping but from Asia so 2-3 week wait.  Or I recommend DigiKey.com in the US where the DF04 is 45 cents each.  Specify USPS First Class shipping which will be about $3 and DigiKey ships same day so you get it in a few days.  Given the shipping cost, you might want to pick up other parts such as the 78L05 fan regulator ICs at 30 cents each, diodes, LEDs, resistors, or whatever's on your shopping list...

Stan,

BF wants to know if it's Q2, IC2 or Q1.  Thanks.

You could probably get all the semiconductors on the smoke unit for a few bucks, then you'd be sure.

Here's a schematic I got here some time back, click on it to expand it.  Hopefully, this will identify the parts, I notice that the two I have in the parts box have the numbers removed from Q2.

The 78L05 5V regulator is IC1.  Note the "D" half-moon white printing on the circuit board matching the "D" shape of the part's body.  The orientation of the part is important with the flat side of the part positioned as indicated.

Josey, OK I found a "deal" for the bridge rectifier.  gunrunnerjohn's comment made me take a look at some other PS1 board I have and one of them uses the DB104 which is equivalent to the DF04. Search eBay for auction 180874558192 and qty 4 of the DB104 is $1.29 with free shipping from Asia.  That's a good deal if you can afford the wait...

Thanks guys!  Have saved the drawing.  Actually we have a good LES (local electronics store) that we make frequent visits to.  I suspect they'd be able to provide the bits and pieces we need.

Pretty much any four terminal DIP bridge will probably work, I've seen many with the same pinout and only minor spec differences.

so if this  78L05 5V regulator is IC1. or the bridge rectifier are the ones that the fan runs on?,,and if one of those goes bad that fan wont run?  with one is the comend one thats goes out the most?and how can you tell if one is bad?

If either D1 or IC1 go bad no smoke fan.  D1 powers the board with DC, so measure voltage at heater element or output of D1.  If you have about track voltage out, D1 is good.  D1 also feeds IC1 to make 5V.  Measure output of the 2 pin fan connector.  If 0 and D1 is good, replace IC1.  G

GGG sre you talking about the one thats next to the big round diod and in front of the AC+ aCG -in put plug??Or are you talking about the one that sits up with a hole tords the top and has 3 prong that goes into the board?

Thankyou GGG!!!!  It was the IC1!!!  Now the fan works!!  Took one from a junk smoke unit board!!

The 78L05 runs pretty warm in those units, the fan draws about 50ma, and the little TO-92 package has to dissipate quite a bit of heat.  I have some Lionel smoke units with the same regulator and they have a little tab clamp-on heatsink hanging off the regulator.

i'd notes it get very warm/hot in the back part of that board.. is that common.?

I'm sure that's the reason that Lionel put the heatsink on some of theirs.  I'm thinking of picking up some small TO-92 heatsinks and installing them.

For those hunting parts:

Not the cheapest source but they have everything you will need:

Digi-Key.com

I get stuff from them all the time, watch the shipping fees.

Parts are cheap but get enough to make the shipping worth it.

You can get the common stuff like the 78L05 & DF04 at radio shack sometimes.

Those are very common parts. but you are paying hi retail at RS.

Actually, I think you are confused about Digikey's shipping policies.  I routinely make small orders from them, and the shipping is typically in the $2-2.50 range for first class mail.  I get them in two days from the order placement.

where do you put the heat sink at on those boards?

The HS goes on the 70L05 regulator, here's one of many examples of heatsinks for the TO-92 package.

how many do you need? I see they fit on the D dio..I know theres 2 of those..proubley put  that on the IC1?? since that drives the fan..

The only thing on the smoke unit that might benefit from the heatsink is the 70L05 regulator IMO.

got 4 df04 and 4 78l05 from digkey..They get a A+ for sevice and fastshipping....Now I got my other smoke unit running now too!