Corona DS-538MG servos
 

http://www.rcuniverse.com/forum/atta...mentid=1911845I purchased these Corona DS-538MG servos for my 3 nitro TT helicopters as the specs seemed great for the price . Found out the other day that these servos shorted and burned a sizeable hole through the bottom of the case while there was no servo action or input , just powered on .Had the heli`s been in flight the servos would have caused an expensive crash and / or possibly hit a vehicle or person . Told the dealer , as they told me these were perfect for the application ..they used them..great saving..reliable ect .Well , when I reported the failure with a photo I was told I should have purchased 100 dollar servos..so much for dealers , dealer claims they will mention it to Corona . So not only was that a lesson learned to stay with reputable name brand products but also a reputable dealer, just glad there was no damage or injury had they were in flight . The price and surface quality may seem to be there but will not purchase there again regardless of they`re experience .

I don't know why the servo failed. Melting like that is unusual, unless the wrong voltage was present.
That aside, I've dealt with Corona in the past (directly) and had no problems in getting warranty service.
They did have a batch of RX's that had problems due to a shrink rap cover stressing the circuit boards and solder joints.

It sounds like you need a different dealer.
In the last year, I've had two bad new servos. (A JR and a Spectrum) One was missing a bearing(out of the box), and the other failed with high current draw when going in one direction.
The dealer replaced both without a quibble.