Neil_Evans Posted January 26, 2013 Share Posted January 26, 2013 Hi, i just bought a couple of hornby dcc chips to fit into my locos. I've got a lima class 60 and a hornby 156. Both have been running fine on dc for ages, but after a nice Christmas present, I'm going dcc. I decided to fit the chip into the 156 as it is dcc ready, so should be a straight plug and play. After following all instructions very carefully, chip was in and ready to go. However, when placing the train back on the track, it seemed to short something out. The lights on the select unit went out and the lcd started flashing "30" and every time it did, the train lurched forward half an inch. I immediately unplugged the unit and took the train off track. The chip was warm. I checked that I'd put it in the right way, and it seemed ok. I tried the other chip, just in case i had a duff one, but the same happened again. I've removed the chip, put the banking plate back in, and it runs fine, even on the dcc layout (address 0). This isn't ideal i know, but wanted to make sure it didn't short any other time. Has anyone else had this? Is it an internal short somewhere? Is there anything i can do? Neil. Link to comment Share on other sites More sharing options...
poliss Posted January 26, 2013 Share Posted January 26, 2013 Look carefully at the socket in the loco to see if there is any stray solder accroos the holes. Link to comment Share on other sites More sharing options...
Neil_Evans Posted January 26, 2013 Author Share Posted January 26, 2013 Had a look at the socket. One small short on the motor bogie pickup wire, however the wire coming from point 1 on the socket isn't connected to anything. Any idea where it should go? Link to comment Share on other sites More sharing options...
2e0dtoeric Posted January 26, 2013 Share Posted January 26, 2013 There often are 'spare' wires coming from the chip. Just make sure there's a scrap of insulating tape on the end, so it cannot touch anything. Also - when you push the chip into the socket, make sure you aren't pushing it in too far - sometimes the pins can go right through, and touch the chassis. Link to comment Share on other sites More sharing options...
2e0dtoeric Posted January 26, 2013 Share Posted January 26, 2013 p.s. What colour is your 'spare' wire? Link to comment Share on other sites More sharing options...
Fishmanoz Posted January 26, 2013 Share Posted January 26, 2013 Pin 1 is the orange motor connection, so you should be able to trace from the socket to the motor. The other grey motor connection is in the diagonally opposite corner pin 5. Then pin 8 next to pin 1 goes to one pickup and again, the diagonally opposite pin 4 to the other. You can see from this that even if you plug in the wrong way around, the loco will still run but all the function connections to lights etc will be wrong. The fact that it worked at all means that both motor connections must be there, so I'd check again for a connection to pin 1. Link to comment Share on other sites More sharing options...
Fishmanoz Posted January 26, 2013 Share Posted January 26, 2013 By the way, I checked this for you on the DCC section of Brian Lambert's excellent site. Well worth Googling him and having a read. Link to comment Share on other sites More sharing options...
Neil_Evans Posted January 27, 2013 Author Share Posted January 27, 2013 The spare wire is coming from the socket, not the chip. It's a black wire, which doesn't really help as they are all black. Ha. How do i know which motor terminal to connect it back on to? Thanks for the suggestion of the site, I'll have a look. Link to comment Share on other sites More sharing options...
morairamike Posted January 27, 2013 Share Posted January 27, 2013 look here http://www.dccwiki.com/NMRA_DCC_Plug Link to comment Share on other sites More sharing options...
Fishmanoz Posted January 27, 2013 Share Posted January 27, 2013 So you can check the pin allocations from the dccwiki site and you should find the wire has to be connected to the motor side which doesn't have a connection back to the socket at the moment. Link to comment Share on other sites More sharing options...
The son of Triangman Posted February 3, 2013 Share Posted February 3, 2013 Aside for the problem, you say the decoder was hot/warm, did you handle the decoder? Components on the decoders are static sensitive so should only be handled with suitable anti-static handling equipment. Touch a decoder and you can kill it or cause long term damage to the components that will cause a fault to manifest itself later on in the decoders life. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.