Two blown chips

richand26mhz

richand26mhz

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Hello. I'm inquiring for my dad. He has recently gone digital using my old lgb mts3. He has recently built a new layout and has made it so you can turn off sections in analogue using a lgb yellow box. in the past month he has had 2 new Massoth L chips blow. The last one today. I chipped both locos one with a digital plug with dip switches. The other I had to remove the electronics and simply plug in the prongs from motor and track. We are puzzled why 2 chips would blow so fast as I never had any issue when I used it on my layout with no issues. Luckily they are both under warranty I just don't want this to happen again. If anyone has any suggestions what might cause this please lete know. Thanks Rich
 
When you say: "..he has .. Made it so you can turn off sections in analogue.."

Does this mean he still has analogue volts available to the track, but can turn a section 'off' from the analogue supply, and use the MTS instead?

How is the MTS power fed to the track-sections? - Does the yellow box switch a section from analogue to MTS, or is there more to it?
 
Can we ask what locos the blown chips were installed it? I'm sure you are aware that an L, like a 55021, is only suitable for single-motored locos..... and even then a "bad" motor can probably pull enough amps to overload one.
What were the circumstances of each faliure - was it immediately that the locos were first run after chipping, or did they run OK for a while and then fail?

Jon.
 
No analogue power connection are present. It's so he can isolate sections but still run digital as not all his locos are chipped yet. The locos are a schomea diesel with the digital connection plate and the other is an older American style 0.3.0. Diesel. both single motor. Apparently they both went pop in a similar area of the track.
 
I wonder if that area of Track is one of the Sections and it was switched off or had the polarity reverced? This might cause a problem. Best way to test that out would be to short the joint (one side of the rail) with a piece of wire, if the Controller Trips you will know that there is something wrong with the wire up. Small chance I know but just a thought.
JonD
 
Yeah, there's nothing fundamentally wrong with having switched sections - I did exactly the same on my line. Do the sections work fine on DC? Hopefully the fact there are switched sections is irrelevant unless somehow a wire is crossed somewhere - but you'd expect that to cause a short when a loco crosses into the section,and the command station would trip out.

Some more detail on when & where the failures occurred might help us come up with other suggestions?

Any Peco points on the line? It's known that sometimes LGB skates can short out where the two V rails are too close at the frog, there have been reports of blown decoders because of this.
 
Nick's point about points reminds me that I have had problems with shorts on R3 and Train Line Points. I have been using bits of sticky tape to stop them though I have not blown a chip that way fortunately. If that started happening I think my Battery Conversions would be starting sooner rather than later. But so far I have still not found a really satisfactory Battery Europen Sound system. All of my Peco are fine as they have been converted to Live Frogs.
JonD
 
Id strongly suspect the area of track is at fault were it happened..if the layout is dcc why do u need to isolate a section of track..also the switch unit...chect that
 
mike said:
....if the layout is dcc why do u need to isolate a section of track..also the switch unit...chect that
Click to expand...
The line started out as analogue DC according to the first post, hence the presence of switched sections.

I deliberately wired my line for DC with sections even though I knew it would be operating under DCC most of the time. I expected I would have occasions to run DC when visitors were around with unchipped locos.

Actually I found it extremely useful to be able to isolate a section when placing a loco and stock on the track - no chance of causing an accidental short and stopping the rest of the line.
 
I was taught to always blow on my chips. :giggle:
 
G-force1 said:
I was taught to always blow on my chips. :giggle:
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Ah, but if you put salt and vinegar on these chips, you are asking for trouble! :(:oops:;)

I would suspect the track in that area.. Check joints for continuity, and possibly contamination for sticky-sap, and the like..
 
PhilP said:
Ah, but if you put salt and vinegar on these chips, you are asking for trouble! :(:oops:;)

I would suspect the track in that area.. Check joints for continuity, and possibly contamination for sticky-sap, and the like..
Click to expand...

Why would poor continuity or dirty track cause a chip to blow rather than just cause intermittent running, Phil?
Come to that, why does a momentary short in the track power (eg with skates at a point frog) affect the chip, which is further "downstream" from the short? I'd have thought that if anything it should affect only the Central Station.
Maybe I'm thinking of it wrongly, so I stand to be corrected....!

Quick question back to Rich, the OP: were both chips purchased from the same place around the same time? Aside from the possible co-incidence of both failing in the same area of the layout, I'd tend to suspect a dodgy batch of decoders......

Jon.
 
Zerogee said:
Why would poor continuity or dirty track cause a chip to blow rather than just cause intermittent running, Phil?
Come to that, why does a momentary short in the track power (eg with skates at a point frog) affect the chip, which is further "downstream" from the short? I'd have thought that if anything it should affect only the Central Station.
Maybe I'm thinking of it wrongly, so I stand to be corrected....!

......

Jon.
Click to expand...

Counter intuitive, but if you get a series of short high-resistance bits of track (talking milliseconds) the CS can supply many amps, but not trip.. depending on the trip-time, and current limit, set on the CS.
So, you can get very short bursts of high-current. These can be too short for the CS to react to, and to big for the decoder to protect itself from..
The 'sharp' edges of these spikes can also damage the electronics, as it tries to make sense of the '0's and 1's' it thinks it is seeing.

Another factor is the motor.. I have had loco's come to me that run poorly on DC, and the motor(s) have seen better days.. If the motor is pulling more current than it should, just fitting 'a chip' will seem to make it better initially, but the failing motor can eventually draw enough current to blow the output transistors on the decoder..

If you look at a 'blown' decoder, it is either the output stage that has gone, or it blows the 'intelligence' at the front-end.
PhilP.
 
Thanks for the explanation, Phil - I knew that things like that sometimes got the blame for damaged decoders, but I couldn't figure out why...?

I can see therefore why the L decoders, with a much smaller current-handling capacity, would be more vulnerable to that sort of thing than, say, an XL/XLS.
I assume that's why it is a good thing to set a variable-current-limit CS like the Massoth Dimax down to the lowest current limit that you can while still providing enough power for everything you want to run on the layout?

Jon.
 
Zerogee said:
Thanks for the explanation, Phil - I knew that things like that sometimes got the blame for damaged decoders, but I couldn't figure out why...?

I can see therefore why the L decoders, with a much smaller current-handling capacity, would be more vulnerable to that sort of thing than, say, an XL/XLS.
I assume that's why it is a good thing to set a variable-current-limit CS like the Massoth Dimax down to the lowest current limit that you can while still providing enough power for everything you want to run on the layout?

Jon.
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Always best to run at the lowest margin you can..
Analogy:
You wouldn't run your domestic lighting with a 30 Amp cooker fuse in circuit!
 
No consolation but the chips should surely be fit for purpose. In my book this includes running LGB skate fitted locos over LGB R3 points.
 
Neil Robinson said:
No consolation but the chips should surely be fit for purpose. In my book this includes running LGB skate fitted locos over LGB R3 points.
Click to expand...

For what it's worth, Neil, I've never seen a shorting/sparking problem on LGB points..... I've only experienced it happening on Peco code 250 points, and on some GRS handmade code 332 ones with metal (dead) frogs....

Jon.
 
PhilP said:
Always best to run at the lowest margin you can..
Analogy:
You wouldn't run your domestic lighting with a 30 Amp cooker fuse in circuit!
Click to expand...

You havn't seen some of the jobs I've been called out to then, Kitchen ring run in speaker cable, rewirable fuse carrier with a nail wedged in it, Garden shed fed by a flex in length of hose pipe, with a taped joint halfway down, where a spade had severed it
 
Zerogee said:
For what it's worth, Neil, I've never seen a shorting/sparking problem on LGB points..... I've only experienced it happening on Peco code 250 points, and on some GRS handmade code 332 ones with metal (dead) frogs....

Jon.
Click to expand...
Definately a problem on some of my R3's. As I mentiond earlier I have put some Insulating Tape on the worse ones, they were second hand so possibly may be out of alignment in some way. Must at some stage do a short Vid to illustrate it.
JonD
 
dunnyrail said:
Definately a problem on some of my R3's. As I mentiond earlier I have put some Insulating Tape on the worse ones, they were second hand so possibly may be out of alignment in some way. Must at some stage do a short Vid to illustrate it.
JonD
Click to expand...

This normally happens with the skates..
We get this on the Harz layout, which is Peco code 250 rail.
It can be cured for most loco's be easing the outside of the skate upwards a little.
 
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