Hardware problem with 464. AY chip fault?

[asapreta]

It is only documented on the Amendment service manual, on the 6128 cost down schematic (page 21) as NR102 and it's a 2.2kx8 resistor network.

Thank you.

[Bryce]

The exact value isn't really important. Amstrad used 2K2 pull-ups, but I tend to use 10K pull-ups on my projects (sometimes called "weak pullups"). I wouldn't go below 1K though.

Bryce.