Jin:
If you are not making "working" hinges you can simply build them from styrene and stretched sprue or styrene tubing
To make the hinge
Cut the anchoring plates from flat sheet styrene to size using the existing as reference.
Cut the "tube" of the hinge from either stretched sprue or styrene tube of the same size.
If you use stretched sprue cut the sprue into sections to show the seperations of the hinge tube
If you use styrene tube score the seperation lines with your hobby knife.
Then position and glue down.
To make "working" hinges there is an article in the Fall 1983 issue of Fine Scale Modeler by Steve Zaloga. You can order a copy (hopefully) of the article from FSM directly.
The article shows how to make working hinges out of shim brass (very thin brass used in machining) wrapped around a styrene pin. These are not hard to make and they do not require expensive tools to make them.
The third method is to photoetch them yourself, now that requires drawing the parts and etching them yourself etc. etc.. Thisagain not a hard process if you understand all the principles involved. However the tools to make your own photoetch parts can be quite costly.
Again search the back issues and articles of FSM and you will find all the information you need to make your own parts. I was fortunate enough to complete the full series of FSM right back to the 1982 test issue and there is a wealth of reference in each. If you have the means to do so I highly recommend locating all the issues. You will not regret it.
Hope this helps to answer your question and fix the problem for you.
Cheers;
Gregory