theproffesor

iTrader: (66)

So I posted this in the electronics section and no luck. The wires pulled out of the case of my 2 wire rc4. I have no problem re soldering on the pub, but I don't know how to open the case. I'd like to not destroy it in the process. I have googled it and can only find a YouTube video that's pretty vague and talks about the old AMB style. Any help would be appreciated. I really like to avoid purchasing another transponder.

Thanks

Bronson

LasagnaCat

iTrader: (161)

I bought a used one a while back with the same issue, it was a PITA but can be repaired. Exacto knife carefully around the edge of the case and it will open. After it's open, the harder part is getting to the board... the whole thing is encased in some sort of epoxy(?) With a lot of melting/scraping/careful picking you can get down to the board for new wires. I just Shoe Goo'd our case back together, complete with the extra big blob by the wires for good measure. It's not pretty but is still working fine almost two years after being repaired.

InspGadgt

With the older model I would cut a strip down the middle and peel it back. Much of the resin stuff they used internally can be cleaned away with a Dremel using a brush attachment of some sort. The wires were surface mounted to the board so it was pretty easy to replace once you could get to the board. Once the wires were replaced I then Shoe Goo the strip back in place and heat shrink the whole thing with clear 1 cell heat shrink from the old round cell days.

theproffesor

iTrader: (66)

I got the case cracked open, and the entire PCB is encased in a hard clear resin. It looks like they filled the case with it, then slid the PCB in before it cured. This is going to be a PITA to fix. The resin has a higher melt in temp than the solder, so no melting it. But I know see why these things are so indestructible, with the exception of the wire exit. It seems this if the would use more flexible wires, this wouldn't happen.

patorz31

Back in the day, when servicing "solid state" equipment, we would use a solvent to remove the epoxy or shellac. Usually acetone or something similar.

mupchu

iTrader: (16)

I had to repair min a while back. Same issue. use some head from a soldering iron, and a dental pick and you can remove it that way, but go slow. you can dremil as well but go slow . . . . there used to be a thread on rctech where it showed this process as well . . . but been a while.

Main thing just go slow and careful.

DesertRat

iTrader: (2)

I had to do almost exactly the same thing, but my transponder was the big older model AMB and I pulled the wires out to where you nearly couldn't even see the break. I tore apart the case with a knife and pliers and the circuit board was completely isolated with epoxy. I cut the wires free of the epoxy, soldered on some new leads, used a little superglue and a big piece of shrinkwrap that I bought a decade ago when I was assembling NiMH cells to close it back up again. Has worked for 2 years since, and it needed a shorter lead anyway.

The most disappointing thing is that from eyeballing the hardware in the transponder I have to estimate it costs AMB about $3 to make one. We're getting robbed.