InitialNik
Student
Hi everyone,
I'm having a problem with a single-slot MVS, model MV1F.
This board had a Z80 error. I've repaired some traces with cables and replaced several chips (Neo-C1, Z80, RAM 6116, etc.). I've checked the continuity between chips and between chips and slots, as well as the Yamaha 3016.
Everything is fine. It's been many days and many hours with this.
I no longer have a Z80 error, but I have no sound.
There's a curious thing. With the oscilloscope, I see that pin 37 of the Z80 has no activity.
A month ago, I received an MVS (same model mv1f) that had no sound, and it was the same case. Pin 37 had no activity. What did I do? I used a regulator to supply 2.5V because pins 36, etc., have that voltage. This gave me a Z80 error. I removed that voltage, and mysteriously, the board started working normally again with sound. I have been testing this base for 2 weeks every day and the sound has not failed again.
I think that was a bit unusual. Obviously, what I did didn't make much sense, but it worked.
That didn't work on this base, which is why I'm asking on the forum, since there are people with a lot of experience here.
I hope you can help me.
I'm having a problem with a single-slot MVS, model MV1F.
This board had a Z80 error. I've repaired some traces with cables and replaced several chips (Neo-C1, Z80, RAM 6116, etc.). I've checked the continuity between chips and between chips and slots, as well as the Yamaha 3016.
Everything is fine. It's been many days and many hours with this.
I no longer have a Z80 error, but I have no sound.
There's a curious thing. With the oscilloscope, I see that pin 37 of the Z80 has no activity.
A month ago, I received an MVS (same model mv1f) that had no sound, and it was the same case. Pin 37 had no activity. What did I do? I used a regulator to supply 2.5V because pins 36, etc., have that voltage. This gave me a Z80 error. I removed that voltage, and mysteriously, the board started working normally again with sound. I have been testing this base for 2 weeks every day and the sound has not failed again.
I think that was a bit unusual. Obviously, what I did didn't make much sense, but it worked.
That didn't work on this base, which is why I'm asking on the forum, since there are people with a lot of experience here.
I hope you can help me.