Littfinski (LDT) TT-DEC gone faulty? - possibly now OK again or maybe not. An intermittent fault?

[melmerby]

Hi all

I have been using an LDT TT-DEC with my Fleischmann TT for some years without a problem.

However, recently it started going to a random wrong position when it received a position command.

After doing that for about a week it stopped moving the TT completely, The relay/solenoid in the TT just clicks and it doesn't move. The red LED on the TT-DEC is flashing.

The TT itself seems to be OK as when operating the lever under the bridge it will move under it's own power without a problem.

 

Anybody had this problem?

I suspect it's a component failure in the TT-DEC.

I'm not sure whether to try and find the fault or buy another, although the price has gone up somewhat since I built mine.

Edited April 2, 2022 by melmerby

[Wacol]

Have you done a test to see if it stops at all the programmed track connections.

 

 If that is ok, perhaps reset it to factory default and then reprogram the necessary track outlets.

 

 

 

[melmerby]

6 hours ago, Wacol said:

Have you done a test to see if it stops at all the programmed track connections.

 

 If that is ok, perhaps reset it to factory default and then reprogram the necessary track outlets.

 

Do you mean using the DCC commands?

Unfortunately it doesn't respond to any DCC commands, there's just a click of the solenoid in the bridge, whatever you send, it doesn't matter where the bridge has been stopped.

You can't make it move automatically at all. Just manually, one step at a time by a quick push of the lever

The above written before I tested it again today.

Strangely it is now working correctly, as far as I can ascertain!

Last night it wouldn't turn, either under control of Train Controller or directly from the Lenz handset.

 

2nd EDIT

It stopped working again and shortly after then started again!

Must be something intermittent😞

Edited April 2, 2022 by melmerby

[Wacol]

Intermittents are a pain.

 

Did you assemble the board yourself? Check for any dry joints. Make sure the IC's are fully inserted, perhaps remove and reinsert. Check all other connections are secure under the screws. Also check the power supply is up to scratch.

 

 

 

 

 

[melmerby]

3 hours ago, Wacol said:

Intermittents are a pain.

 

As reparing faulty electronic equipment was part of my job for many years, I know all about intermittents.☹️

Dry joints are not a thing I normally get with my assemblies, although I suppose there's always a first time!

 

The supply wont be a problem as it is a quite beefy 16v AC 90VA from a toroidal transformer.

[melmerby]

Bit puzzled by this as it seems to go for a while and then goes haywire, however after a bit of prodding around it seems to have settled down again.

 

I took the opportunity to give the bridge a bit of a service - lubrication and suchlike.

Seems a bit smoother now, although still a tendancy to bind in a couple of places when turning.