has anyone attempted to repair a Lionel CW-40 transformer?

The Lionel CW-40 & 80 transformers are "not" repairable. LIonel at one point was replacing the 80's with new ones after they failed in the warranty period. You had to cut the cord off before sending it back to Lionel. I suspect they just threw them out in the trash.

 

The most likely part blown is the triac. don't know the part number-- But een if the part was to be replaced, there is probably other damage, likely the microprocesser chip. wish I could be more optomistic--- 

A friend of mine that has repaired several of the CW-80 units told me that about 50% of the time the trouble was a simple fuse that is wired in the line in the unit. The trouble is that if UL is like it was in the old days you need to replace any part with the exact same part or you void the UL label. This may not stop some garage repairmen but Lionel, I am sure, would not want to risk their UL listing.

 

Al

Many Thanks for the input.  

 

We opened it up today and spotted a small and obviously blown surface-mount capacitor, close to the AC input from the transformer. There appears to be an in-line fuse in one output lead from the transformer, covered with shrink-wrap. The transformer had output through the fuse to the board and the cooling fan operated. I suspect the blown capacitor is just the visible manifestation of a problem in something else.  

 

Solution: we will look for a replacement transformer with a higher rating.  

 

One good thing about a blown CW-40: it would be very easy to convert it to a fixed voltage supply. Just cut out the circuit board and run the transformer output directly to the output terminals. The hardest part is, you need a special triangular screwdriver bit to open the case.

 

Just the first time.  Use different screws to put it back together.

I don't have a board to look at but a few Comments. The wire that looks like it is labeled R8 may be a fusable link on the input side of the transformer or a current sensing link used to trip the breaker. The little thing that went may be one of the TVS devices everybody keeps talking about.

 

Al

I haven't studied the circuit in great detail but I reckoned R8 was a current sensing link as you mentioned. The location of the blown component is labelled C1 so I assumed it was a capacitor, I think it's part of the filtering for the AC from the transformer. If it was my transformer I might try replacing that, but since it's a low value transformer, and the owner has agreed to buy a higher rated unit for a nominal price from a friend's stockpile, I'm not going to put any more time into it.

 

Thanks again for the comments and ideas.

 

TVS= Transient Voltage Suppressor

When you need to deal with  that type  of screw, try a triangular file to remove the screw. You can buy security screw bits in a set for prices from $1 to about $8.

Try Harbor Freight or Dollar Tree.

 

Al

W.

You need a long bit to reach the screws in the Lionel transformers, so the best bet is to simply grind down an old screwdriver and make the proper bit.  Harbor Freight doesn't have that bit in a long shank.

Capacitor may not be blown, just the trace.  you could jumper in with solid wire and see if that restores it.

 

BUT, something was failing to prevent that damage from occuring.  G

This failed CW-40 has ended up in my possession. The owner traded it to my train-repair friend towards an older Lionel transformer with a higher rating. When I have more time I'll try figuring out the full extent of the failure.

 

FEC fan mentioned "The most likely part blown is the triac." I'd like to test that just out of curiosity.

 

As gunrunnerjohn observed, it takes a long shank to reach the "security screws", and we ground our own.

 

GGG, the component formerly at the location labelled "C1" is totally vaporized and it burned some of the circuit trace. When I tried jumpering a small capacitor across it, it burned more of the trace.

 

The transformer component tested OK so I could easily adapt the unit to a fixed voltage supply, or use a voltage regulator circuit to create a variable DC supply. But it's way down my list of pending projects!

 

Thank you all for your input.

After a little research I found that amazon.com has the triangle screwdrivers kt, part number ATKTR4 from Silverhill Tools.   Under the reviews for Silverhill ASD3T someone posted a review that this fit the CW-80 transformer screws.

ACE,

 

Did you ever get to root cause?  If not, where is the little guy now?

 

Can one even buy a CW-40 anymore?

 

I ask because I'm in the market for two things

1. low-cost transformers for accessories on my layout (Conventionally controlled with blocking and automation via relays)

2. a busted CW-40 or CW-80 for a special project I've had in my head for a while.  All I need is the 120-18 step down transformer out of one.  I know I can get this type of transformer elsewhere, but I don't want to pay lighting showroom prices!

You will probably have the best luck finding a cheap cw80 on ebay. Occasionally they show up here on the forum too.

You may also try to find an electrical surplus store nearby to see if they have any old transformers. In Orlando, there is a place called SkyCraft and they have tons of old electrical stuff including transformers.

The last CW-40 I have bought cane with a Polar Express starter set a couple of years ago.
Always on the bay. About $20-30.