I know that the iron pens of the cartridge get dirty after all those years. You can
clean them and they should work perfect.

But how to clean the cartridge slots of the MSX itself???

Some of my original cartridge games just don't start up and the MSX boot up in basic.

A bit stranger is for example king's valley 2 where at random the scc sounds mutes and you only hear psg. If I press on the cartridge the scc sounds returns.

I have cleaned the cartridges but I think that the catridge slots of my MSX also need some cleaning.

Does someone have some tips???

Quick'n'Brite!

Latok, you changed carreer or something?

seriously... The Philips NMS8250 has a design flaw in the audio mixing. In my case it causes to mute the FM-PAC for a while (in the beginning) and later returns to normal. I haven't had any problems with any SCC doing the same on it though. And the audio thing is fixed.

alcohol in spray (the one that don't have that 2% of water), is called in spanish "isopropilico" i not found the word for english.

i have the same problem with my NMS8250 .....................
first i tought o no i blew out the buffers

i vacuum cleaned the slots and carefuly removed the slot print with the ribbon cable on it i cleaned it up with some contact spray and it works again

o yeah let the spray dry first its light flameble so you could light up your msx

sucses with cleaning your slots

I cleaned my cartridges with alcohol 70%, do not get confused with alcohol 120%

Shall see if I can remove the cartridge slots and put them in a bucket of pure alcohol

Thx for the tips ya all.