On Fri, Jul 10, 2020 at 12:31 PM Vincent Mallet <vmallet@...> wrote:
Thanks Siggi. The scope is a 2465 300Mhz, S/N B027189. I don't see any smd
Yeah, only (some of) the -B version has SMD on the A5 board, as I
I don't think the scope has any options but I'mWell then, I guess you need to dig in, see what's up. In your shoes I'd
start by verifying that U2556 is getting 5V and ground.
You should then be able to check whether the U2556A inverter is driving
its output by measuring the voltages on pin 1 & 2. It should be safe to
test the inverter by shunting its input to +5V and GND through - say - a
100Ohm resistor to see whether it can drive both up and down.
Maybe you want to test R2571 & R2573 as well as C2572. There have been
cases where these 0.1uF capacitors have gone leaky, and that might be
enough to bring down this oscillator.