Comments on: Phonola NMS 8245 (MSX 2) Repair

By: juan

juan — Wed, 01 Apr 2020 14:37:40 +0000

Replaced video RAM chips with sockets… the same. Some times, touching around the flat chips and the oscillator X1, it shows a blue screen (or cyan … and sometimes trush on the screen). Do you think that the oscillator X1 can be broken? (4Mhz)

By: Juan

Juan — Tue, 05 Nov 2019 11:44:55 +0000

The system RAM is in sockets now (I forgot to say)… I replaced the chips with new TMS4464 and the behaviour is the same.

I removed the cartridge socket and … I will do the same with video RAM but… when I power on the computer, the keyboard does not work (no click sound and CAPS does not switch on the led).

If the problem is in video RAM… the computer should start up… or am I wrong?

Thanks for you help.

By: Juan

Juan — Mon, 04 Nov 2019 18:24:08 +0000

Hi again,

I replaced NEC RTC chip and installed sockets for main RAM (4 chips) … there is no difference.

The voltage is ok in all the chips of the board but I can remove Z80 and ROM… no difference in screen (an small “jump” in tv when I switch on but black… there is video signal… black). Both chips were tested in another NMS8245.

Any idea? thanks.

By: xAD / nIGHTFALL

xAD / nIGHTFALL — Mon, 17 Sep 2018 06:01:36 +0000

@Juan Probably one of the System-RAMs burned or in short-circuit , also check Video-Ram.

By: Juan

Juan — Sat, 15 Sep 2018 23:18:17 +0000

Hi,

I have one of these machines and I only get a black screen. The voltages are OK and, looking around for information, I replaced the RTC chip and tested with Z80 and ROM working in another 8245… but only black screen.

Can you give to me any idea?

By: xAD / nIGHTFALL

xAD / nIGHTFALL — Wed, 13 Jun 2018 07:59:00 +0000

@Fabrizio Radica Ciao, mi sono recato verso un fornitore di componenti elettronici locale con la cinghia spezzata e ho cercato tra le cinghie che avevano in negozio quella che si avvicinava di piu' all'originale.

By: Fabrizio Radica

Fabrizio Radica — Tue, 12 Jun 2018 15:12:43 +0000

Davide : Ciao, mi occorre il tuo aiuto. Ho un Philips NMS8245 perfetto, nuovo in quanto pezzo invenduto del negozio di mio padre. La cinghia del floppy è essiccata e spezzata. Dove hai trovato il ricambio? Grazie mille in anticipo, buone feste!

A distanza di 4 Anni, cerchi anch'io la stessa cinghia. Grazie :)

By: Davide

Davide — Thu, 25 Dec 2014 11:08:08 +0000

Ciao, mi occorre il tuo aiuto.
Ho un Philips NMS8245 perfetto, nuovo in quanto pezzo invenduto del negozio di mio padre.
La cinghia del floppy è essiccata e spezzata. Dove hai trovato il ricambio?
Grazie mille in anticipo, buone feste!