In recent years, there has been a growing interest in leveraging deep learning and neural networks to address scientific problems, particularly in solving partial differential equations (PDEs). However, current neural network-based PDE solvers often rely on extensive training data or labeled input-output pairs, making them prone to challenges in generalizing to out-of-distribution examples. To mitigate the generalization gap encountered by conventional neural network-based methods in estimating PDE solutions, we formulate a fully unsupervised approach, requiring no training data, to estimate finite difference solutions for PDEs directly via small convolutional neural networks. Our proposed algorithms demonstrate a comparable accuracy to the true solution for several selected elliptic and parabolic problems compared to the finite difference method.