Lgb 50100 Jumbo Transformer Help Please

[lgbmad]

Good evening all
I am after some advice please regarding a Jumbo unit I have. The unit has been stuck in the loft for some time because I knew it was faulty.....infact when I first purchased the unit it looked like some one had dropped it from the top of a block of flats. Even in its box with all the internal packing it had taken a hell of a hit. The unit was purchased with a group of other items from an auction so at the time I could not return the unit .
Anyway, I decided this weekend to put what i could back together for a test, all the securing screws that hold the top casing to the main board were smashed but to be fair the actual circuit board seems OK. All relevant control knobs etc were put back in place as they had all been knocked out of their rightful locations. I powered up and there was that nice buzzing sound you expect to hear and the Volts & Amps dials all lit up. I thought great.......until I pushed one of the direction knobs.........even with the main speed control knob turned to zero the unit output 24 volts and the loco I had on a rolling road for testing the unit just about took off. No matter what I did with any of the control knobs the unit gave out 24 volts and would not drop.
So would anyone know if there is anyone who specializes in repairing these units and also has spares, because if the unit can be repaired I will need a new case so the main base can be screwed back onto the case. The volt and amp dials are working fine so can be moved over into a new case. I did find a small gold coloured piece of metal in the main box wedged into the internal packaging.......I cannot seem to find anywhere it may of come from?
Thank you in advance for any help.
Kev

 

[Nodrog1826]

Looks like a switch contact, given the rounded tip, may be from one of the four buttons..

Not sure if this helps, pics of the guts of the unit on Flickr...

https://www.flickr.com/photos/63076212@N08/5952630060

 

[PhilP]

Looks like the lucar terminals on the left side of the board could do with pushing on a little better..
Also large rectangular resistor on right-hand side appears to have broken away at one one? - towards the rear..

If you get full-whack all the time then feedback / control has gone.. Could be a cracked track on the board, but check that resistor first..

 

[Brixham]

Have you got the 9 way 'blank' D connector plugged in?

There is a loop of wire inside this plug.....without it I have a feeling that the output is always at full voltage.
Or is it the other way round....without the plug there is no output.

I have the pinouts somewhere if you've lost the plug.

Malcolm

 

[lgbmad]

Looks like a switch contact, given the rounded tip, may be from one of the four buttons..

Not sure if this helps, pics of the guts of the unit on Flickr...

https://www.flickr.com/photos/63076212@N08/5952630060

Thank you for the link, funny enough that was the only link i could find myself on the internet.
kev

 

[lgbmad]

Looks like the lucar terminals on the left side of the board could do with pushing on a little better..
Also large rectangular resistor on right-hand side appears to have broken away at one one? - towards the rear..

If you get full-whack all the time then feedback / control has gone.. Could be a cracked track on the board, but check that resistor first..

Hi Phil
thank you....have you got x-ray vision or are you looking at the pictures on flickr?
Kev

 

[lgbmad]

Have you got the 9 way 'blank' D connector plugged in?

There is a loop of wire inside this plug.....without it I have a feeling that the output is always at full voltage.
Or is it the other way round....without the plug there is no output.

I have the pinouts somewhere if you've lost the plug.

Malcolm

Malcolm my friend you may have it........just had a look in the 'D' plug holes and there seems to be a broken wire in one hole......and there is a mention of a jumper wire that needs to be removed prior to fitting remote control........going to have a go now........back in a bit
Kev

 

[lgbmad]

Malcolm my friend you may have it........just had a look in the 'D' plug holes and there seems to be a broken wire in one hole......and there is a mention of a jumper wire that needs to be removed prior to fitting remote control........going to have a go now........back in a bit
Kev

Malcolm you are the oracle for today.........I could not get the broken wire out so I managed to find a thinner piece of copper wire to squeeze beside the broken piece, the other end into the hole that would of been lined up with the bridge......and hey presto away we went. This just means I wont be able to use a hand control unit unless I can find a way of getting the broken wire out, but the unit is up and running. I cant test the auto acceleration and braking etc as I do not have the necessary contact switches at the moment, but just to know the unit is up and working is great.....Thank you all for the feedback and help .
All I need now is another case to replace this broken one, so if anyone has a case they would like to sell or know where I can get one that would be great.
At least now I can run some of my bigger loco,s with plenty of vava voom!!!!
Despite the rain.....a brighter day here for me now
Kev

 

[Brixham]

FAB.....

considering how much the Jumbo cost new...how much extra would have been a switch on the back for internal or external control? About a quid. Or two at the most!

 

[stevedenver]

not certain I can be of help
but I have one of these jumbos, and here are some low level brain waves for you:
1 is the starting track voltage pot turned fully counter clockwise? this is the pot in the pair to the right of the large control , of the pair it is the closest to the control knob-in fact they all should be counter clockwise for testing-the starting track voltage could be high enough to make a loco move , but not as though full 24 volts.

2 in the back of the unit, dead center, silver, is the plug for the tethered remote unit, if the tethered unit is not being used , the outer most 2 plugs in the upper row must be connected (jumped, linked in the US sense) . LGB supplied a u shaped metal pin to achieve this. I would tell you without hesitation that a paper clip bent so as to fit these two outside holes would do fine, if less than elegantly. I have the tethered unit, but have yet to use it. thus , while I know these two outside holes must be linked or jumpered when not using the hand unit, I DONT know what happens if they are not.

3 lastly, the large control pot itself might be damaged. while not an expert, I have dealt with pots on my electric guitars and amplifiers. The contacts and shafts inside the pot can be bent, broken, and even slip out of lock. There are typically bronze like sweep contacts against a wound backing board. as i recall too, there is usually a black round thin piece of paper or carbon type board too, as an insulator I think-its been a few years.....

yours might be stuck at the end, full tilt, even if you feel the shaft itself moving when you turn the big red knob. If you're brave and nothing else comes up as a solution, (ie have nothing to lose), I might take a careful look at the pot and try to detach it form the unit board, and then carefully remove its round metal backing-the ones I have use tabs to close them, and these can be gently prised straight and the round metal cap backing removed for a gander at the inside. Knowing german tech, your LGB pot is likely soldered closed with borium.....LOL

The good news, sorta, would be that any LGB controller would likely use a similar or identical pot--possibly an expensive part source. If not, a nice large potentiometer control can be located at an electrical supply.

best of luck

 

[lgbmad]

not certain I can be of help
but I have one of these jumbos, and here are some low level brain waves for you:
1 is the starting track voltage pot turned fully counter clockwise? this is the pot in the pair to the right of the large control , of the pair it is the closest to the control knob-in fact they all should be counter clockwise for testing-the starting track voltage could be high enough to make a loco move , but not as though full 24 volts.

2 in the back of the unit, dead center, silver, is the plug for the tethered remote unit, if the tethered unit is not being used , the outer most 2 plugs in the upper row must be connected (jumped, linked in the US sense) . LGB supplied a u shaped metal pin to achieve this. I would tell you without hesitation that a paper clip bent so as to fit these two outside holes would do fine, if less than elegantly. I have the tethered unit, but have yet to use it. thus , while I know these two outside holes must be linked or jumpered when not using the hand unit, I DONT know what happens if they are not.

3 lastly, the large control pot itself might be damaged. while not an expert, I have dealt with pots on my electric guitars and amplifiers. The contacts and shafts inside the pot can be bent, broken, and even slip out of lock. There are typically bronze like sweep contacts against a wound backing board. as i recall too, there is usually a black round thin piece of paper or carbon type board too, as an insulator I think-its been a few years.....

yours might be stuck at the end, full tilt, even if you feel the shaft itself moving when you turn the big red knob. If you're brave and nothing else comes up as a solution, (ie have nothing to lose), I might take a careful look at the pot and try to detach it form the unit board, and then carefully remove its round metal backing-the ones I have use tabs to close them, and these can be gently prised straight and the round metal cap backing removed for a gander at the inside. Knowing german tech, your LGB pot is likely soldered closed with borium.....LOL

The good news, sorta, would be that any LGB controller would likely use a similar or identical pot--possibly an expensive part source. If not, a nice large potentiometer control can be located at an electrical supply.

best of luck

Thank you Steve
in the end it was the jumper that was missing, and the picture of the gold metal I placed was infact the broken jumper which has now been replaced near enough to your suggestion of a paper clip. So all is well and the unit is up and running, I still need to find another jumbo case as mine is lacking all the screw mounts that have been totally broken off....but as long as I donot intend to lift the unit around too much is still good to go.
Thank you again
Kev

 

[stockers]

Sounds like a job for sticky tape!

 

[lgbmad]

Sounds like a job for sticky tape!

I think you may be right.......its already had the hammer treatment, so its only right to use the next best thing in the tool box....that being the sticky tape (in red of course)
Night all.......or morning depending what part of the hemisphere you are living in

 

[stevedenver]

might i suggest a strong waterproof contact cement such as for cloth. i use quick grip here in the us, tenacious but will let go with strong steady pressure

 

[KeithT]

Glad you appear to have it sorted, at the price it is too valuable to simply leave unused.
In fact it has reminded me that quite some time ago I bid on ebay for a Jumbo unit and controller. They were timed to end within seconds of one another. I ended up with the control unit but not the transformer!!! As a consequence it has just languished in its box as I went over to MTS.
Time to get rid of the controller I think.

 

[lgbmad]

Glad you appear to have it sorted, at the price it is too valuable to simply leave unused.
In fact it has reminded me that quite some time ago I bid on ebay for a Jumbo unit and controller. They were timed to end within seconds of one another. I ended up with the control unit but not the transformer!!! As a consequence it has just languished in its box as I went over to MTS.
Time to get rid of the controller I think.

Hi Keith
you are right, a lot of money to be left in the loft, at least it is in the fresh air at last. I have to say though, despite the awful treatment the unit has sustained in the past (not by me I hasten to add) .......it is still running as it should, a great testament to German engineering.
Hope you have managed to avoid all that snow we are hearing about.
Take care
Kev