Loose chips

[MarkSG]

OK, so I've finally got round to making the switch to DCC, and have just chipped my first loco - a Rapido/MR J70, using a Zimo MX617N chip. It's fine. It runs. Woohoo!

 

But... the chip doesn't seem to want to stick in the socket. I assumed that it would be a fairly firm push fit, and, once in, would stay there. But, it isn't, and doesn't. I'm pretty sure it's in as far as it will go, as pushing harder doesn't seem to help (and it must be in far enough to make contact, and the right way up, because it runs). But, because it's only a loose fit, it works free while the loco is in motion. And then, of course, it stops working!

 

At the risk of asking what may seem like a dim question, is this normal? How firm a fit should it be? And, if loose chips are a common problem, what's the best solution for making them stick?

[Kaput]

The pins on Zimo 6 pin decoders are a bit overly long for most sockets in my experience.

 

If its not going in very securely the options are either, cut the pins a bit shorter or try and bend a little kink into a few of the pins to give it more grip.

 

Failing that a bit of kapton tape over the decoder and socket to help hold in place can work.

[MarkSG]

8 minutes ago, Kaput said:

The pins on Zimo 6 pin decoders are a bit overly long for most sockets in my experience.

 

If its not going in very securely the options are either, cut the pins a bit shorter or try and bend a little kink into a few of the pins to give it more grip.

 

Failing that a bit of kapton tape over the decoder and socket to help hold in place can work.

 

Thanks, that's useful. The pins do look long compared to the socket, but, as I'm not an expert, I wasn't sure whether that was because I was doing something wrong! I'll try adding a slight kink and see if that helps. If not, then I'll try some tape. That was what I'd thought of, anyway, but I thought it would be wise to just get some advice first in case there was a more obvious solution that I wasn't seeing.

[WIMorrison]

I find that you need to use more force than you might expect to get them into the sockets - once in correctly they are very tight. If they are coming loose then that suggests they are only resting in the socket and not yet pushed in.

 

Shortening the pins wont make them go in any better (or further). If you find that there is free pin showing AFTER they have been pushed fully in then you may want to shorten the pins to remove the bare bit showing after you have pushed them home. Some models need the pins shortening to allow the body back on - but do not do this until you know what it feels like for the decoder to be correctly fitted 

[Crosland]

Shortening the pins won't make it fit in any better but beware some sockets can allow long pins to stick out the other side and short out on metalwork.

 

So shortening can prevent shorting

[rab]

I used to find chips stayed in place when wrapped in newspaper.

Hat, coat, wish my legs would carry me a bit faster

Edited June 28, 2020 by rab

[MarkSG]

In the end, I found that gently bending all the pins was the solution. Partly, it gives them more "stick" in the socket, but it also means that the chip itself presses down slightly on the chassis which helps to hold everything in place.

 

I've also now chipped my Hornby J15, which was a lot more straightforward. Hopefully the rest of the locos will be, too.

[MarkSG]

1 hour ago, rab said:

I used to find chips stayed in place when wrapped in newspaper.

Hat, coat, wish my legs would carry me a bit faster

 

It did occur to me, afterwards, that I should have titled the topic "Loose Chippings", and illustrated it with this image!