I recently purchased 2 of the SUBOR (xiaobawang 小霸王) Famiclone SB-926 with keyboard (zhongyingwen diannao xuexi ji 中英文电脑学习机). They didn't work at first (controller port problems, cold solder joints, etc) but after a good cleaning and solder reflowing they both came back to life. Last weekend for fun I swapped out the capacitors on one of the systems with rubycon capacitors. I checked the old caps and their ESR and capacitance (uF) were not good. Here is a list of the caps I replaced.
The AV/power board I replaced 5 caps
(1)10uf 25v
(2)1uf 50v
(2)100uf 16v
The cartridge board had 2 caps
(2)1uf 50v
The AV board was fun to remove (the image is before i swapped the caps). I included some photos.