Riva Lima

Simplesmente vergonhoso que a Casio tenha implementado um midi tão ruim no antigo MT/CT com apenas 4 canais midi! Entretanto, ao mesmo tempo, a Yamaha nadava com o seu PSS com midi, onde conseguiram ter os canais 1-16 com velocidade em midi também (o canal 16 era bateria, só depois de implementarem o canal 10 padrão para ritmos)... por isso a Yamaha se saiu muito melhor e foi muito mais aceita por quem gostava de produzir coisas com mais de 4 canais, ao contrário da Casio. O mais interessante é que mesmo naquela época a Roland, com seus módulos sintetizadores profissionais como U110, U220, D110, só tinha 8 canais para sequências midi, a Yamaha implementou 16 canais midi completos para seus portatones...

Finally solved! The problem is with the 'Sample Hold' chip... I just changed it and it's back to normal. To everyone who tried to help, thank you very much, and I hope that the solution will be a reference for someone who goes through this one day. Video abaixo

I'll do it, I didn't think I could! thanks for the tip! Good week

These are not useful, the search is for service manuals, for maintenance... those mentioned are operating manuals, which are easily found on Google. I just got the service manual, it's above.

Guys, I got the service manual to MT400v, I'm posting it for all... https://drive.google.com/file/d/1wrsjkiLiFo4w-gsI-i6DkahMg4AgkZc0/view?usp=sharing

Guys, I got the service manual, I'm posting it for all... https://drive.google.com/file/d/1wrsjkiLiFo4w-gsI-i6DkahMg4AgkZc0/view?usp=sharing

Mais um vídeo mostrando o que realmente acontece com ele, com ritmos e algumas melodias mortas

Would anyone have downloaded and would like to make the MT400v service manual available? My keyboard has the melody chip muted, only the rhythm and filter parts are working... it would be generous if someone could help us

Hi, thanks for taking the time to respond! I did tests with the diodes here to detect any defects, also with the flat cable that connects to the main board, and there is no problem between them, I did a continuity test on the cable from one side to the other, and everything appears to be fine. , apart from the fact that the keyboard melody part doesn't work haha, but let's try other possibilities!

Here's an interesting detail that I only noticed after increasing the amplifier volume a lot... it's possible to hear the notes, but at a very low volume, beneath the amplification noise... can you hear them?

Hello again! Yes, I did the tests with the multimeter measuring the resistor that is heating up, and its value is still within, no changes... also the transistor, it is in perfect condition... I'm back to square one... the accompanying sliders , rhythm, all of them, are working normally... no sound from the keys yet... mystery... without the specific electrical diagram for it, it gets very complicated, and the service manuals for other MTs are very confusing For me, apart from the fact that some components are on different boards, it is much more difficult to interpret.

Could you repost these service manuals? Or send it to me by email please? stereokromatik@gmail.com

This 220r 1/4W resistor is getting very hot, is it the culprit, or is some component nearby causing it to get hot?

I will try this, thanks!

Many thanks for the reply! Unfortunately, I didn't find any service manual, so I don't know exactly which resistor would be damaged, without specific guidance on where it would be on the board, it's difficult to identify where it would come from... of course, I have a multimeter, but measuring resistor by resistor, it's a very arduous and difficult task but I will try the other tips which are also important! But it would be very interesting to know where exactly the resistor would be... I looked for a service manual for it and unfortunately I couldn't find it anywhere.

Maybe it would be a resistor... but I did a visual inspection and didn't see any leaky or bulging capacitors

Hey, guys! I hope everyone is well... I bought a classic MT400V, but it came with a problem, of course I bought it at a lower price than normal, as this problem is affecting it... the keys don't work, except the main part. accompaniment, all the keys in this section respond to the accompaniment chords... however in 'solo' mode none of the keys work, even with the accompaniment activated, the rest of the keys do not contain any sound! I've already opened it and it doesn't contain any stains of corrosion from the battery, apparently everything is clean from the factory... any idea what could be happening? Yes, it came sounds with the speakers and the L and R output sound connected to the normal keyboard outputs.