GNS-MS01 speaker system bizarre problem

[twoferns]

The subwoofer quit working twice in eight months. The service person here in Brazil said the motherboard had burned because the multi-core cable connector (multi pin DIN socket) was slightly bent. He claims this happened both times. Yamaha Brazil replaced the subwoofer twice. The problem is that I expect this so-called burnt mother board problem will happen again and I'll be out of warranty. I'm in the process of trying to get a call back from customer service here in Brazil for a better explanation. I tried to get information from someone in the US but they referred me back to Yamaha Brazil. The repairman here said the cable is so flimsy that I can't even breathe on it, and that I should leave it plugged in all the time. I have always been super careful when connecting the cable, and I rarely disconnect it. So I am sure that I have never bent it. If someone has had this problem or heard of it, please let me know. Thanks in advance.

[EB5AGV]

Are you sure they blame the MIDI cable and not the speakers one?. Because I don't see the link among the subwoofer and the MIDI

Jose

[tyrosaurus]

On the Genos speaker system (GNS-MS01) there is just one multicore cable which carries the line level signals from the keyboard to the amplifier in the sub unit, and also carries the amplified audio signals for the speakers from the sub unit to the keyboard.  There is no MIDI signal connection!  The OP (and the technician! ) is mistaken about the cable being for MIDI, although the plugs are vaguely similar! 

Yamaha insist on using the same compact/cramped multi pin DIN socket as they used on Tyros models, but this time all the connections between the keyboard and amplifier/sub are made with this one socket and cable.   On the Tyros4 and earlier systems the amplified signal for the left speaker was sent back to the keyboard via a separate 1/4" audio cable.

The multicore cable was known to give problems on Tyros models if it was flexed a lot, but this didn't usually cause the amplifier board to fail!  I assume that Yamaha expected that the cable would not be connected/disconnected or flexed a lot since the system is intended for home use.

However presumably on the Genos version if a short circuit or open circuit does occur between pins or conductors in the cable, then unless the amplifier's speaker outputs are protected against short circuit or open circuit, this could cause the amplifier board to fail.

They may already incorporate such protection in, but if not then Yamaha need to redesign the amplifier board with such protection so that problems with the cable or sockets do not cause a meltdown of the main amplifier board!


Regards

Ian

[twoferns]

Thanks very much to Jose and Ian for your quick replies and for clearing up my confusion on the cable type. I thought it was a MIDI because of the round shape and the pins. The repair technician claims this cable became very slightly bent and that this somehow caused the motherboard of the subwoofer to burn. I have a hard time believing that is the problem. But I'm still trying to get hold of someone here in Brazil to talk to. Again, thanks for the info and best regards.

[tyrosaurus]

How are you using the speaker system?

Are you regularly connecting and disconnecting the cable to the keyboard?

Are you regularly rolling or folding up the cable when not in use?

I would not regard this cable, its plugs or sockets as being suitable for either of the above.

The fact that you have had two similar failures already, and that the complete sub unit was replaced both times (rather than just being  repaired) tends to exclude a faulty socket on the sub, and instead suggests that the cause of the problem may be in some way related to how you are using the equipment.

However it would be useful to you (and perhaps others) if Yamaha or their technicians would provide details about the nature and likely cause of the problem, assuming of course that someone has actually examined your failed units! 


Regards

Ian

[twoferns]

I use only in my home. I don't unplug it very often. I don't roll or wind the cables. Just place them loosely on top of keyboard case. From the time I first received these speakers with my Genos I noted that the DIN cable was tinny and flimsy and I was very careful when connecting it. I was afraid it would wear out with much use. I've only had to disconnect a couple times when we had some work done in that area and I didn't want to leave it exposed. I'm shopping for another speaker system because I figure this subwoofer will go dead again. When I finally make contact with someone here who knows something, I'll update. Thanks for your input.

[twoferns]

Update to my problem with the GNS-MS01: I have been going round and round with customer service through emails. They contacted the authorized dealer who evaluated my speakers. The dealer told customer service what he told me--that the DIN cable somehow became bent and "burnt" the subwoofer. I told customer service that I believe this explanation is unsatisfactory, but I keep getting the same answer. They have even implied that I "forced" the cable into the socket, and this is simply not true. I don't unplug the subwoofer often. It is not close to a wall, and there is nothing putting pressure on the DIN cable.

The emails I receive from Yamaha didn't give a name or an ID of the customer service rep. I asked for identification and for a real address where I can send a formal letter of complaint, but so far I haven't received an address or a phone number. I asked to have this matter elevated to this person's supervisor, but that has not been done as of this writing.

[EileenL]

You will find a list of Yamaha addresses in the back of  the manual. Just look up the one for your Country.