Sounds like you blew the motor. Honestly, I would just ditch the thing. A&K does make some good stuff, but their SVD is not one of them. Alot of the internal components from A&K tend to be garbage as well. Motor included.
The A&K I worked on never really performed all that well. I worked some miracles on it to get it halfway decent, but a Cyma/echo1 would be a far better choice all around. (The Cyma and Echo1 I am 99% sure are the same with some minor differences in internals.) I had a Classic Army and it broke in half under the weight of its own barrel. (Not even joking.)
Long story short. Suck it up and buy a Cyma or Echo1. CYMA Standard SVD-S Airsoft AEG Sniper Rifle with Folding Stock (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
Echo1 Red Star AK CSR Airsoft AEG Rifle, Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
CYMA Standard Full Metal SVD Dragunov Airsoft AEG Sniper Rifle w/ Synthetic Furniture (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
Technically the SVD-S would be the most "modern" version, if you care about being "Milsim Accurate".
While the SVU would be nice due to its smaller form factor, I wouldn't get one. (I have one.) Battery space, and disassembly are a nightmare.
The A&K I worked on never really performed all that well. I worked some miracles on it to get it halfway decent, but a Cyma/echo1 would be a far better choice all around. (The Cyma and Echo1 I am 99% sure are the same with some minor differences in internals.) I had a Classic Army and it broke in half under the weight of its own barrel. (Not even joking.)
Long story short. Suck it up and buy a Cyma or Echo1. CYMA Standard SVD-S Airsoft AEG Sniper Rifle with Folding Stock (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
Echo1 Red Star AK CSR Airsoft AEG Rifle, Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
CYMA Standard Full Metal SVD Dragunov Airsoft AEG Sniper Rifle w/ Synthetic Furniture (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
Technically the SVD-S would be the most "modern" version, if you care about being "Milsim Accurate".
While the SVU would be nice due to its smaller form factor, I wouldn't get one. (I have one.) Battery space, and disassembly are a nightmare.