If its not one thing its some thing else turns up just when you think you have found the problem and put the engine on the track bang something you over looked pops up or didn’t account for.
I have thought keep putting the engine on and off the track is a pain why not a simple test unit? Will give it some thought.
Look closely at the picture here you might be able to spot the capacitor with a big black burn mark in the centre of it.This component should be a nice deep yellow colour all over with a orange line denoting the positive end and some writing saying 47uf 25v.
The reason for this capacitor burning out is due to the little black square component to the right which is a bridge rectifier and this had for some reason stopped working and just gone into a full short and stopped giving out a DC output so by sending the wrong polarity to the capacitor thereby making it go pop.
That’s all part of life I can remember back in the 1964 working for a small electronic company and my job then was testing TV repeater amplifiers they were then switching from valves to transistors and this unit I was testing had Mallard OC71 transistors like in the picture some of you may have come across them. The TV amp problem was a 50 cycle hum which I had spent a long time trying to find out why I decided to leave the unit powered up over night and go home as I switched off the room lighting I could see the scope and the fault went I switched on the light and the fault came back.
The picture here is of such a transistor and is coated in black paint this is because the transistors are made from a clear glass tube this paint had got damaged in the wiring shop and it was this that made the transistor now light sensitive and was picking up the mains 50 cycles from the room lights. The OC72 has a metal case, the red dot is the collector lead. To remember the 3 transistor leads we had a saying. From the red dot it was... Cross the British Empire or Collector, Base, Emitter a bit of history
Having said all that it still leaves me to find out why this servo board is not working I hope its not the SSR as its my last one and I will need to reorder some.
I thought I would add this as some might find it interesting, in the first picture of the tank engine in the section you can see my oiling pen this is great for electric and steam engines it has a very fine needle so you can get into some tight places it is filled with clock oil of about the right viscosity and just right for small moving parts I find this oil ideal for live steam engines.
Years ago the Tri-ang company sold oil for there electric train which I can remember having a small bottle of just as the picture. it had a short brass wire fixed inside the cork to drip drops of oil onto moving parts
The live steam engines have many oiling points and if you look at the under side of the Hornby engines there are 4 main oiling points which need frequent attention even full size engines had a good oil up before starting a run.
There are the 3 main driving axles and the gear bearing block.In the picture I’m oiling the rear set of drives and the very thin needle goes right through the plastic brake ssembly oiling hole and into the cavity of the axles and bearings.
And do not forget the tender wheel set axle boxes and the power pick ups these are most important the axle boxes can seize up which I have had and will wear a flats on the wheels and once corrected you end up with tap, tap, tap noise as the train runs round the track. The same problem has happened on full size electric rolling stock when the hand brake has been left on.
Well looks like I’m burning some night oil to see if I can get this PCB fixed as until this is done I can not take the next step which is to see if steam can be raised and a run under taken.