NEC's PC-8801 series is the gold standard of Japanese hobby PCs. PC-8801FH was released in 1986. The MODEL 30 that I got was 168,000 yen.
The first step was to replace the electrolytic capacitor and the rechargeable battery. I was lucky that the rechargeable battery did not leak.
The rechargeable battery used for my FH was a YUASA Ni-Cd rechargeable battery, 2.4V, 30mAh. Since the same battery is already unavailable, I bought a replacement from Amazon and replaced it.
I also replaced the electrolytic capacitor. Several tantalum capacitors were used, but nothing was done this time.
After connecting the FH to the monitor and turning on the power, the ROM BASIC screen was displayed without any problem.
The reason why I can't see the edges of the screen is that the video frequency of FH doesn't match the displayable frequency of my monitor.
