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View Full Version : been given a challenge on fixing a fried transmitter


nivlacf1
17-09-2015, 09:21 PM
Ok so ive been given a spektrum dx3s that had a lipo conversion, the guy that had it connected the battery the wrong way round and blew it,(reverse polarity) ive been looking into if its fixable or not and what might of got damaged, has anyone ever repaired one of these, know of someone who has, or a link to a guide? i can not seem to find anything other than it could need the capacitors replacing, any other ideas would be greatly appreciated thanks

beale
18-09-2015, 05:41 AM
Very difficult to assess without testing components, it will depend on how long the connection was made to how far the problems will go, first thing is to visually inspect the boards for damaged components and replace these, (probably hard to spec if damaged so will need a donor to compare) then a specialist would test each component using an oscilloscope before power testing as you may have short circuits. Connect AA batteries to test, why a lipo was used I do not know the handset batteries last months in my DX's

mattr
18-09-2015, 06:20 AM
LiPo?
A fully charged LiPo will probably scramble the insides of the Tx anyway.
Sure you don't mean a LiFe?

why a lipo was used I do not know the handset batteries last months in my DX'sThey last about 8-10 hours in my DX3R Pro, maybe 6 or 7 in in its predecessor (DX3C). (Thats decent alkali batteries. Duracell etc)

With faffing around, forgetting to turn it off, testing stuff and so on, that's only 2 track days use, maybe 3.

The LiFe conversion (6.6V IIRC) i charge about once every month. When i think to do it, rather than when it dies.
Next radio i'll probably try with eneloop rechargeables.

mattr
18-09-2015, 06:24 AM
Oh, and FWIW, if you do manage to fix it, fit a servo plug (M/F) as the battery connector. + on the centre pin, - on one of the outside pins. Then it's impossible to connect in reverse.