I'm not sure if this should really be posted in the electronics section. I'm always looking for feedback though as invariably someone has a useful comment, so I chose here, to hopefully get more views (and comments).
This was an Ebay rescue tank i got for $35 shipped. It had 2 return rollers missing. As the photo shows I replaced the missing return rollers. The replacements were from Welsh Dragon. The rollers are different from the other 4 already there. I'm going with the back story of wartime improvisation and all that-because I don't want to risk cracking the hull by prying the other 4 off to replace them.
Anyway the transmitter part of the post: On another post I commented how i dropped the Heng long 2.4 Ghz transmitter (Tx) for my Ebay rescue Pzkfw Mk III, and after that, there was no turret traverse. Being a closeted OCD type this naturally made me irate. This is my interim solution to dropping transmitters.
Someone suggested to try taking the Tx apart. Having done just that with the RX18 Tx I was not optimistic at first. As there seems to be nothing inside the RX18 type Tx that's remotely repairable. However I followed the suggestion and removed the back cover. The 2.4 Ghz Tx is actually very different-it's simpler and has a modular design-plug in components. A HAH! Something to work with at least!
I figured it must be THIS part-the module that controls the turret. Well that proved to be a wrong assumption that i'll explain in a minute. But the important thing is, this module just plugs in. That means, of course, parts can be swapped from good Tx's to bad ones to fix them.
Having no source for Tx spare parts that i know of, i ordered another transmitter for $40
from Ebay. After 3 weeks it arrived. I installed new batteries and-NO RED LIGHT. 
. But wait-i have ANOTHEr transmitter, known good EXCEPT for the turret module! I'll just swap the part from the new Tx into the broken one. I do just that-TURRET STILL DOES NOT WORK!!! That means one thing, the turret module was actually good, its the module it attaches to that's broken. Well I don't care about fixing that right now-If i get ONE good Tx out of either one, that's enough for me. So now i swapped that module back into the new Tx. (the turret control is held in by 3 screws and plugs into a 6 wire connector).
Next problem: The red light on front still doesn't come on, of course. After probing with my multimeter looking for voltage i- I see there is zero voltage coming from the battery bay connector. And having seen this happen before with other Tx, I know what the problem is-those molded plastic "separators" in the bay itself. (I cannot imagine what the designer was thinking when he decided to have them molded in the battery bay, as they clearly have NO purpose other then to cause functional problems!).The seperators often cause the batteries in each row to be too far apart to make a proper circuit, and if this is the case with a Tx they need to go! Time for the dremel...5 minutes later, the plastic separators are gone. I reinstall the batteries and hook up the back cover connector to its module-the red light blinks on at long last!
I put the rest of the Tx back together, carefully-now to bind the Tx to the Rx in my Panzer III. The headlights go from flashing to solid, success! Now i feel almost giddy, like Thomas Edison, as i test my newly fixed Tx-and accidentally drive the tank right off the table
! Fortunately not TOo much damage done...mostly to my hull hold down mod, nothing major cracked or broken except for the spareroad wheels on the hull top...took the opportunity to paint the tires and drove the tank outside for a while in a victory lap...I'm seriously thinking of making some kind of foam case for my transmitters...any ideas?
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