Electrotren E3119 fan power - help please RAF96! (and others)

[ellocoloco]

On the Electrotren ALCo 321 - E3119, that I have recently repainted - see Hornby Int'l section - I have an issue on reassembly. I know Rob has one of these and may have encountered a similar problem and can suggest where I start looking!

This loco has a powered fan operated by F3 on DCC. On reassembling the loco after painting the fan is permanently running. Although I think this is a physical issue rather than strictly DCC I have posted here in case anyone has experienced similar. Loco has a lokpilot V4 and was factory fitted. I have reset the decoder via CV8 and there is no difference. I have also swapped the decoder with a Lenz to rule out a decoder fault with no difference.

I have inspected the wiring to the fan unit for damage caused when I repainted the model. In order to remove the bogie side frames for painting I had first to remove fan unit and disconnect the driveshafts from the top of the gear towers. On reassembly all other functions work fine. I do not see any damage to the wiring to the fan - the red and blue wires - and wonder what else to check before I cut one of the wires!

In the picture the fan unit is unscrewed. Any suggestions would be appreciated.

[Jupiter 1707822591]

By swapping the decoders you may have eliminated a decoder fault .So a fault on the PCB could be possible .can you convert the loco back to dcc ready .and what happens on DC .

[96RAF]

@elloco

The 21-pin decoder I had installed in mine controls the fan on F24 which is a low level 3.3v digital function not a high level 12v output. This suggests there is further electronics on board the loco pcb to make that digital on-off into a usable voltage for the fan. Likely to be a transistor or mosfet acting as a relay.

I will take a look at mine later as it already has the top off awaiting an adapter as my diesel decoder test articles in hand are presently all 8-pin.

I don’t have any wiring schematics for these Electrotren locos but I will see what I can get from Hornby when they are back after today’s public holiday for the funeral.

In the meantime you could try disconnecting both fan wires at the pcb and check using a meter to see if those terminals react to F-key operation, thus proving if the fan is at fault or not.

[ellocoloco]

@Jupiter. Thanks for the suggestion. I swapped out the decoder for a blanking plate this morning and the loco performs as expected. Fan comes on as power is increased. No apparent issues on DC.

@RAF. Mine is DCC fitted from new and I worked fine before I got my hands on it! The Lokpilot instructions state F3 for the fan and I haven't tried to remap it to somewhere else. (I keep my DCC messing about to just the address!) I didn't have any DCC confusion recently so I don't think I have changed it accidentally. When painting the chassis underside I put masking tape over the top of the chassis covering the PCB, motor, LEDs etc and if some paint got in, it is not obvious. I was also careful on removing the tape in case any wires got pulled from the PCB. Again, no damage is obvious.

Fan just won't switch off!

(Edit: I have a Roco Multimaus and cannot go up to F24 as your Fan is set on. Will look at the terminals later.)

[96RAF]

@elloco

Don’t let the F24 (or remapping) confuse you, that is just my test decoder. The point I was making is it is a low level digit output not a full fat voltage like F0, etc. Has your controller got the fan as a latched function - i.e. turn it on, turn it off.

I looked at mine and apart from finding a broken wire which explains the lack of number plate lights at one end (soldering iron out another day) there is no obvious trace visible on the pcb to which components feed a triggered voltage to the fan. It would need someone more skilled than me to put the meter across it.

[ellocoloco]

@RAF

Yes it works as a latched function, F3 to turn on then press again to switch off. I have not tried disconnecting the fan at the PCB as it is working normally under DC, that is starting when power is applied as expected so I reckon that won't prove anything to disconnect it.

It has occurred before, I found this on Spanish forum Forotrenes: Problem with the 321 ADIF fan. If you are in touch with any of the Hornby repair guys can you ask on my behalf please? In the meantime I'll live with it and disconnect it if it becomes too annoying!

Cheers.

[96RAF]

@elloco

I have been in touch with Hornby about this and after reaching out to their overseas rep they tell me they have no access to any International brands loco schematics or PCB design, and that such data is held close to the chest of the respective source manufacturers.

Sorry that I could not be of much more help in tracking down the fault.

The only thing I can recommend is a direct approach to Electrotren support themselves, if you find them as Hornby bought them out in 2004.

[ellocoloco]

Hi RAF,

Thanks for trying.

The model was announced in 2008 as 8pin and was first listed as having a 21pin connector in 2014, so all produced under Hornby ownership. The three earlier 8pin locos I have are trouble free. At some point I will have a close look at the connector as it is working on DC so I reckon that's a good place to start. I would like it to work, for no other reason than to make it work, but its one of those gimmicks that I don't need and may well end up disconnecting it.

I'll let you know how I get on if I ever get round to it!