Need help with Canon T-90 *Second Curtain Problems

I just got a nice shape T90 and I managed to fix the "not firing at all" problem already and it fire smoothly. Then I face another problems, which is the second curtain won't open and end up in "EEE" on screen.

I'm pretty ok at assembly and disassembly it but not sure what is the main issue part.

Need help for few specific part suggestion.

Thanks

This is from an old post on Flickr:

"The EEE fault is caused by one of two things, it's either a microswitch jamming or the firing coil needs replacing. Turn the camera on and take a shot, which will bring up the EEE code. Hold the camera about 4" above a wooden desk and bring it down with a sharp but gentle thump on the base! Try this a couple of times. If you still have an EEE code, use the battery check button to clear it."