I reckon the 2-truck 38 ton Shay has a type of oscillator circuit to drive a yellow and red led with out of phase pulses to create flickering effect for both fire box and the ash pan. there are 3 wires going from the main PCB to the each flicker LED board. in the exploding diagram it's not clear what is on the LED board what the three wires are connected to... I was not able to find a part number of picture for the LED boards... alas I messed with it trying the reverse engineer the waveforms and the red LED blew up with a loud bang, it sounded like some capacitor actually blew up.... anyways modern decoders have flickering function built in that is randomized over time for much more realistic effect, so all I need is to dig in there and replace each flickering LED board with some modern LED's and hook it up to my decoder....  the issue is that it's not clear to me how to access these boards or what does they look like...

anyone has experience with this? namely where the flickering LED boards are located, what they look like and how to access it ?

thanks

Well, I have experience, but not sure if I have a SCHEMATIC for the flicker circuit..

do you have the wiring assembly? that shows what wires go to what boards.

but they did not provide the SCHEMATIC...

So, you said how to access these boards... simply  put you can see them in the exploded wiring diagram.
The shape, locations of wires and approximate size can be told from that too..

I'm looking at my pdf file, G821X- (page number)

do you have this? pages 5 and 6 have the information.

I believe the firebox board is in the firebox, but some of the circuitry may be on another board.


Perhaps we can ensure you have the right document, and all you are asking where are the boards and what do they look like?

ok, so it turned out that I just blew the red LED in the ash pan (the fire box LED's are fine and  now working properly ) so I need specifically  to access the ash pan (mounted under the body) and replace the LED/ any PCB it might be soldered to. I have the exploded diagram, it seems the ash pan underneath the loco is  G811X-00P03 on the first page ? is that right ?

Yeah, it seems so... it's a poor document, as the board shows in the later pages but on the wiring diagrams, not all the boards have the part numbers identified... pages 5 and 6

thanks, I will follow

I may be asking a trivial question, but being new to Bachmann through the acquisition of this collection item, I wonder why this company has given up on the G scale shay and Climax / Heisler products.... no new models, no parts or support .....

So, the market has changes since the "heyday" of large scale, and Bachmann sort of stopped the 1:20.3 stuff, but I hear they are considering bringing back one of the locos in 1:20.3 ...

The market is smaller, and with tariffs the prices of locos have skyrocketed to the US.

Hang in there...

Greg. Don't leave us hanging...........

Apparently there will be some new "Aristo re-issues" soon, announced at an east coast show.