Hello,
I have a Yamaha Dx7 Mk1, when playing a chord/note with an “infinite” sound, for example a pad, and holding it for several seconds suddenly the sound cuts off. This error happens randomly, sometimes it cuts off after a few seconds, other times the error never happens, and other times it takes around 20. …30 seconds or more.
Perhaps this problem is something common that happens in these models of keyboards that are already quite old. To complete the information on mine, I leave you these details.
This Dx7 has never had a repair from any technician, the battery has not even been changed. Right now the battery indicates 2.8 volts
It does not have any modifications or RAM memory additions. It is just like the original.
I have a sound card, it reads perfectly, and it actually makes the same error as with the internal sounds. When playing a prolonged chord at some point it cuts off and stops playing, then if you play the chord again it plays again until it happens. the failure again.
The Volume control works, but the “Data Entry” control apparently is not working.
The rest of the buttons and functions have no problems.
Its long past due for a capacitor replacement. All DX’s need a capacitor replacement after 35 years.
The issue is the electrolyte in the capacitors are corrosive and corrode the inside of the cap, making them fail or be unreliable, or have capacitance read out of spec, or leak onto the circuit board and corrode the traces. After a point the voltages go out of spec and damages the chips on the motherboard.
Tantalum capacitors fail either by exploding in flames, or shorting internally without any external evidence. Yes the memory battery needs changing.
If the memory battery reads higher then 3 volts means the tantalum cap in that part of the circuit has failed, so yours hasn’t failed yet, or is about to.
The RIFA caps are famous for burning up. When they fail, the unit can be turned off, but when shorted can turn the unit on, even with the switch turned off. they are a must change as any power line spikes can cause them to explode.
There is no fighting it, you need a qualified tech to change many capacitors.
as no one has worked on it, any tech will love it. as other peoples work will not have to be checked.
