Moonglum Posted December 31, 2019 Share Posted December 31, 2019 The 4F was running then after a very minor derailment started to short the system every time I tried to start it. It would move forward for half a wheel rotation then the system would crash. I looked to see if there was anything touching, the wheels the tender connection etc but could see nothing. I tried it on my dc layout and it tries to go. It will sometimes travel, bumpily, for a couple of inches then stop or it will slowly move a millimeter at a time. A buzzing noise comes from the engine at times or it makes a ticking noise when the power is turned up. Link to comment Share on other sites More sharing options...
walkingthedog Posted December 31, 2019 Share Posted December 31, 2019 Sounds like it has picked something up like a track pin. Maybe that's what caused it to derail. Link to comment Share on other sites More sharing options...
Moonglum Posted December 31, 2019 Author Share Posted December 31, 2019 I couldn't see anything but I haven't been able to work out how to get the body off, the service sheet doesn't tell you. I have seen a message on here describing how they took the body off but it sounds pretty scary. Not plucked up the courage to try it yet. Link to comment Share on other sites More sharing options...
walkingthedog Posted December 31, 2019 Share Posted December 31, 2019 Check behind the wheels on the loco and tender. Link to comment Share on other sites More sharing options...
Moonglum Posted December 31, 2019 Author Share Posted December 31, 2019 I have checked the wheels, as best I can, without removing the body. I can't see anything there. However I did try running the engine on DC with only the tender wheels in contact with the track. The wheels of the locomotive revolved and kept revolving. When I put the locomotive on the track too, it did travel around the track but only at about 40% power. If I increased the power it started to stutter again.I tried the same thing with tender only on the track, on my DCC layout. The locomotive wheels would do one to two revolutions then the entire system shorted.I have no idea what that all means. Perhaps it gives you, or someone, some clues. Would an object taken up allow the locomotive to work, sort of, on the DC layout? Link to comment Share on other sites More sharing options...
Moonglum Posted January 2, 2020 Author Share Posted January 2, 2020 Has anyone any suggestions regarding my last post? I'm beginning to think that it is something other than some debris, but no idea what. Link to comment Share on other sites More sharing options...
walkingthedog Posted January 2, 2020 Share Posted January 2, 2020 Have a look inside the loco or the connection between the loco and the tender. Post some pictures so we can see what is what. Link to comment Share on other sites More sharing options...
Rog RJ Posted January 2, 2020 Share Posted January 2, 2020 Try a new decoder as the existing one may have been damaged. Link to comment Share on other sites More sharing options...
Moonglum Posted January 2, 2020 Author Share Posted January 2, 2020 Thank you for the replies. Tomorrow I shall take it apart and probably fit a spare decoder. Although not a TTS chip is should show if it is the problem lies there. Link to comment Share on other sites More sharing options...
Moonglum Posted January 3, 2020 Author Share Posted January 3, 2020 I took it apart and could not see anything that looked amiss. I put the chip into another locomotive and that sailed around the track. I then placed a blanking plate in the Fowler. No response from the locomotive other than the blanking plate became hot and smoke started to arise. That was only after a few seconds of trying to get the engine to move. Link to comment Share on other sites More sharing options...
walkingthedog Posted January 3, 2020 Share Posted January 3, 2020 Did you put the loco fitted with the blanking plate on to a DCC track. If so it will smoke. Non DCC locos cannot run on a DCC layout. Link to comment Share on other sites More sharing options...
Moonglum Posted January 3, 2020 Author Share Posted January 3, 2020 No. I put it on a DC track. Link to comment Share on other sites More sharing options...
walkingthedog Posted January 3, 2020 Share Posted January 3, 2020 And the blanking plate smoked. Have the pins on the plate gone in too far so they are touching the chassis? Link to comment Share on other sites More sharing options...
Chrissaf Posted January 3, 2020 Share Posted January 3, 2020 This is really where you need to invest in a Multimeter. Without one any diagnostics and testing are just not effective. You can get a Digital Multimeter off ebay for less than £10 delivered. With the meter on the resistance scale you can start looking for the source of the short circuit that your smoking blanking plate is indicating.. Link to comment Share on other sites More sharing options...
96RAF Posted January 3, 2020 Share Posted January 3, 2020 Most Lidl or Aldi sell capable multi-meters for a tenner. Link to comment Share on other sites More sharing options...
Moonglum Posted January 3, 2020 Author Share Posted January 3, 2020 I don't think the pins are in too far. I think the tender bottom is plastic anyway not metal.I shall have to get a multimeter, though haven't a clue what to do with it, but expect I will find out, one way or another. Link to comment Share on other sites More sharing options...
96RAF Posted January 3, 2020 Share Posted January 3, 2020 https://www.howtogeek.com/318722/how-to-use-a-multimeter/ Link to comment Share on other sites More sharing options...
Moonglum Posted January 3, 2020 Author Share Posted January 3, 2020 Thank you for the link, I shall read through it. Link to comment Share on other sites More sharing options...
Moonglum Posted January 9, 2020 Author Share Posted January 9, 2020 Well I have now got a multimeter and I understand the theory behind it. I know where to plug the cords in and how to set the voltage but.....where on earth am I supposed to put the probes? I have put them on the pairs of wheels that have pickups and they all registering 9v I think, apart from the middle two wheels on the tender which don't register anything. That could be down to me not touching the right bits at the right time though. Link to comment Share on other sites More sharing options...
96RAF Posted January 9, 2020 Share Posted January 9, 2020 We are looking for continuity between pins on the DCC socket (no decoder plug or blanking plate installed), which means you put the meter on Ohms and the probes in the appropriate sockets on the meter (then with the loco off track and the body off for access) and probe each pin in sequence and each other pin on the socket.E.g. Put one probe on socket pin 1 and the other probe on each other socket pin in turn. Report.reading - either 0 (continuity) or zillions (infinity = insulated).Move the first probe to the next pin in sequence and repeat the second probe pin to pin track - Report.Move the first probe to pin three and so on until you have gotten to pin eight then you have fully traced the state of the socket.. Where there is continuity between adjacent pins that means a solder track is likely and you need to lift the socket and view the connections under a magnifier to see if there are so.der tracks twixt pins. You will find a reading across the motor brushes as the armature windings connect these two pins. OK ??? Link to comment Share on other sites More sharing options...
Moonglum Posted January 9, 2020 Author Share Posted January 9, 2020 I don't seem to have anything on my meter that says ohms. I followed the instructions for continuity testing, as described in the meter's booklet. I put the range finder to the position they recommended and tried the probes in the pins. I should have recieved an audible buzz if there was continuity but I didn't get a single sound. I tried pin one with all the others and pin two with all the others then gave up. Link to comment Share on other sites More sharing options...
96RAF Posted January 9, 2020 Share Posted January 9, 2020 Continuity is measure on the Ohms scale designated by the greek letter Omega - Ω - as seen arrowed below . If you put your leads into the arrowed sockets .../media/tinymce_upload/a6414b7a496b123621dcb55105165cd7.png ... you will know you are connected correctly on the right range when you touch both probes together - the buzzer will sound and the scale will show a short . Link to comment Share on other sites More sharing options...
Moonglum Posted January 10, 2020 Author Share Posted January 10, 2020 Thank you for that. I did find the ohms section in the end but the probes don't give a buzz on any of those settings. They do give a buzz on the settings advised in the meter's booklet (the yellow section on your photo). At least it proved to me that the meter does give a sound. However it does not give any sound when I have the probes to ANY combination of pins on the locomotive. Link to comment Share on other sites More sharing options...
96RAF Posted January 10, 2020 Share Posted January 10, 2020 Some meters will buzz when you touch the probes together on any ohms scale but some only when it is on the diode check/buzzer (dot and expanding arcs) symbol as pictured. Yours is obviously the latter, so you will have to look at the scale and if you see zero ohms then that is a short. If it is a very high reading (infinity) that means it is open circuit indicating there is no continuity between the pins you are probing. If you are not seeing continuoty then all is well but I would expect to see a reading when the two motor pins are probed as the armature windings are connected through these two pins. All the others should be open circuit. Link to comment Share on other sites More sharing options...
Chrissaf Posted January 10, 2020 Share Posted January 10, 2020 In general, the continuity buzzer will only sound when there is a dead 'short circuit'.....that is what the 'continuity test' is designed to do. For the type of diagnostics you want to do, you are much better using the ohms (Resistance) scale and reading the numerical value on the display. This will be far more relevant and reliable as a test..The two extremes are usually zero (a full short circuit) or OL (or a horizontal bar "---") which usually means infinity resistance or open circuit. But where the measured value lies between these two extremes then you should get a numerical value on the display....read on..Subject to the meter you are actually using, either the meter will 'auto-range' and just give you a numerical ohms value. Or if not 'auto-ranging' you have to manually choose a range with the rotary switch that gives a numerical number on the display. The number is then relative to the range selected..Using Rob's meter image above as an example, there are five resistance ranges as indicated by his red arrow:.Switch position 200 = 0 to 200 ohms.Switch position 2,000 = 200 to 2,000 ohms.Switch position 20K = 2,000 to 20,000 ohms.Switch position 200K = 20,000 to 200,000 ohms.Switch position 2000K = 200,000 to 2,000,000 ohms..Lets say for example that the resistance being measured is 50 ohms. On most manual meters you will only get this numerical reading on the 200 switch position. On the other four switch positions, you are more likely to see a 0 value. Therefore, if you start with the meter on the 2000K position and read 0, you choose the next lower switch position and test again. If you still get 0, you choose the next lower switch setting and so on until you get a definitive numerical value or a zero on the 200 range if it is truly a 'short circuit'..If measuring across the motor, you are likely to see a reading typically of 150 ohms +/- 75 ohms..So on a DCC ready loco with the blanking plug fitted..If measuring between the left side wheels (pickups) and the left side motor you should see a value close to zero. Similarly the right side wheels (pickups) to the motor right side should see the same numeric value..Across the wheels, you should see the motor winding resistance either in or close to the range I have indicated above. If this reading is significantly below 75 ohms then consider some form of 'short circuit' fault is present..The test results I have indicated above are not valid for the same tests when a decoder is fitted. The meter on the resistance scale will not be able to read a resistance value through the decoder if it is in circuit..If you do not have a 'blanking plug' to fit, then refer to the diagram below (courtesy of Brian Lambert's web site....Flashbang on this forum). The readings below assume that neither a 'blanking plug' nor a 'decoder' are fitted to the socket../media/tinymce_upload/dac8ba1e6fe1e058f0effbdd4c167252.jpg.You should have a meter reading close to zero when measuring between:.Pin 1 and the right hand side brush on the motor.Pin 5 and the left hand side brush of the motor.Pin 8 and the right hand side wheels (pickups)Pin 4 and the left hand side wheels (pickups).Note that sometimes locos leave the factory with crossed or mis-wired wiring, So be prepared to not get the exact same continuity connections as detailed above. The above represents what is correct as per the NMRA wiring standard..Then between Pins 1 & Pin 5 you should see the motor winding resistance as documented previously above..With no 'blanking plug' nor a 'decoder' fitted, you should see an open circuit (infinity) resistance reading between:.Pins 8 & 4 Link to comment Share on other sites More sharing options...
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