joff-turbo-nova Posted February 10, 2019 So last week I needed to open up a 12v 80's era signal unit as the green LED was starting to fail and I wanted to see if I could repair the unit, as second hand ones are close to £20 delivered to me. First job, break out the scalpel and unseal the unit... This gives us the components - front , back and circuit board... The red LED was working fine... The green one not so... It's a simple circuit design with 2 LED's and one resistor to drop the voltage to 2.2v Sourced some replacement LED's from eBay which will work around the 2.2v area... And then proceeded to unsolder the old green LED and replace with the new one.. Then time for a test.... All was good so the unit was resealed and ready for further duty. I've never seen the insides of one of these units or even any pictures on the web, so here you go.. Jonathan Share this post Link to post Share on other sites
Arrow Posted February 10, 2019 (edited) Wow! Good job man! I always wanted see what's inside those signals. Good to know there are spare leds working for this beautiful 80's era electronic! Edited February 10, 2019 by Arrow Share this post Link to post Share on other sites
bricks n bolts Posted February 11, 2019 Good to know what LEDs to use to fix these, thanks Johnathon. Share this post Link to post Share on other sites
LEGO Train 12 Volts Posted February 11, 2019 Thank for sharing! Great work Share this post Link to post Share on other sites
