and Since then dreamcast only shows black screen ...
I connected dreamcast to treamcast VGAbox(TV mode) but it also shows black screen.
I experimented most of CD-R and It seems that the number of laser movement repeating is exactly the same with normal conditions
So I think that GD-rom is still working correctly.
I did continuity test on FL401-FL405 filter which is connected to display signal.
https://www.dreamcast-talk.com/forum/vi ... 1&start=10
And I found that resistance between ground soldering joint(orange arrow in jpg attachment) and signal soldering joint(black arrow in jpg attachment) in FL401-FL405 filter is not opened But it is 75ohm.
I measured FL601-FL607 filter, which is closed to controller cable connector, its resistance is infinite(opened).
and I also measure FL406 and FL407, which is closed to CE403 capacitor, and It is also opened.
Is it normal to get 75 or 80 ohm when I measured resistance between ground soldering joint and signal soldering joint in FL401-FL405 ?
If it is abnormal then Where can I purchase these dreamcast filter(FL401-FL405)?
Any reply would be appreciated.