Working on a circuit board which has what I believe is a crystal oscillator but cannot find any information on the particulars.
The label say SKC4.000M5. The part is 3/8 inch long by 1/8 inch wide and I would guess it is a 4 Mhz crystal oscillator. Can anyone assure me of this? Do these things go bad? I can only get 60 hz for the frequency using a Multimeter.

 

Working on a circuit board which has what I believe is a crystal oscillator but cannot find any information on the particulars.
The label say SKC4.000M5. View attachment 207079The part is 3/8 inch long by 1/8 inch wide and I would guess it is a 4 Mhz crystal oscillator. Can anyone assure me of this? Do these things go bad? I can only get 60 hz for the frequency using a Multimeter.

It looks like a standard 4Mhz Crystal as you describe. You won't be able to measure it with a multimeter. Like any component it can fail, i would suspect other issues before changing it though.

 

I would guess it is a 4 Mhz crystal oscillator. Can anyone assure me of this? Do these things go bad? I can only get 60 hz for the frequency using a Multimeter.

4MHz crystal. They rarely fail. Can't measure with a multimeter.

 

Thanks Dennis and Marc

 

Thanks Dennis and Marc

If they've experienced physical abuse, they can fail; even if it's just dropping them.

 

Thanks Dennis.

 

Here is the latest, using a Hantek scope I find a strong 60 hz signal, as was found with the MMD, when measuring across the the installed oscillator. I do not seem to find this 60 hz signal anywhere else on the 18 pin microcontroller. Any thoughts?

 

A 60Hz signal suggests either bad grounding for the scope, or the power supply to the board has a blown diode (or similar) or regulator.
With a bad power supply to the board, it is possible the micro is blown, especially if the voltage is too high. Crystal may not oscillate if the micro is dead.

 

The power supply to the micro-controller is a flat 4.9 volts DC. I tried various combinations of the 18 pins on the micro-controller chip and only get the 60 hz signal with probes at each xtal (pin 15 and 16) location for the crystal. I even tried making a small wire arc of an antennae to see if it was coming through the air in the vicinity of the crystal but got nothing. Got me stumped.