Reply 20 of 58, by Maxvintage871
Hello all,
Again, great ideas to try.
I am brand new to taking any scope measurements. Please let me know if I did something wrong or if I should change anything. My probe was set to 1x, and I used auto range for the divisions.
Reading off of the OSCO pin on the KBC socket you can see the first photo attached. The clock looks really messy, but I think that is correct. There is both a 6mhz and 12mhz signal on the pin (again, I think).
Reading the clock off of the POST card on the clock LED is my second photo. Again, super messy and this one makes less sense to be messy. I see 8.28 Mhz, but the signal is all over the place.
Onto trying the MMX, I promise no MMX were hurt in the taking of this photo. The system was powered on for maybe 3 seconds. I left the heatsink off so as to show it was an MMX and I did verify on VCC2 there was 2.33volts and on VCC3 there was 3.43 volts. The split voltage jumpers are just below the socket. Unfortunately, no change to the post code either using Post1a or the original BIOS (the original BIOS has that C sticker on it and the post1a bios is at the bottom of the photo).
I put the bestkey KBC back into the socket as that doesn't seem to be making a difference. Also, while looking around for a good ground for the scope, it looks like the board's 5v rail is 4.45volts. Does this lead anyone to ideas? Could this be a real problem or is 4.45 volts not low enough to be an issue?