Glitch with BYTE
ZXNet echo conference «hardware.zx»
Hello, All
Recently they gave me another Byte. There's a strange glitch in it. After switching on it loads
normal, but after loading (Barsika) the keyboard does not work. Clicking a button
COMBINATION did not help. The image test (L+B+A+reset) did not start - it happened
normal reset. I think the keyboard is dead or the cable is broken. Second
unlikely. It had not been opened before me. Would replacing the keyboard board help?
to another (I won’t remove the cable from the byte - I’ll use it from the keyboard)?
P.S. I'm fiddling with this byte because it contains all the memory for RU5 G, its
It's easier to upgrade.
Hello BYTEMAN
"Barsik" is BASIC? Didn't any of his kanders fall off at INT?
Hello BYTEMAN
Or there is a problem with INT.
Hello fan
fan> "Barsik" is BASIC?
Yes.
fan> Didn't any of his kanders fall off at INT?
I don't know. I'll check it now. Where exactly should the capacitor be located?
Hello BYTEMAN
Try following the path from the processor leg "INT".
Hello BYTEMAN
I have no idea.
We need to take a closer look at what these mikruhs are generating.
Hello fan
fan> Try to follow the path from the processor leg "INT".
Oddly enough, there is no connector there... INT goes only to the system connector and
to other mikrukhs. Maybe I wasn't looking carefully? What is the serial number
Conder?
Hello fan
1. if the test for L+B+A does not run, then this is not a matter of the int falling off (because
the test polls these buttons not at the interrupt, but direct)
2. IMHO there is nothing to die in the keyboard.
Now I don’t have the diagram at hand, but perhaps there is some kind of buffer on the SHA or
The SD (well, for example some kind of AP6) goes to the keyboard, then maybe it died.
Hello Sinus
Okay, let's see. And what pins on the byte board itself can be short-circuited so that
find out if a byte is dead or not (to hear a click)?
Hello fan
Thanks to everyone who helped.
Didn't do anything. I had to disassemble it for parts. :v2_wink2: