I know this question has been asked many times before, however this question differs in the use of an uneven set of capacitors.
I'm replacing the crystal on an old computer.
The original symptoms were as follows: If the crystal got hot enough the system would start up, heating up the crystal by aiming my hot air station at 100C for 2-3 seconds would heat the crystal enough for it to work a few minutes.
I replaced the 32.768kHz crystal marked with S3238E with a new one (32.768kHz, 12.5pF) however although the system is less sensitive to the crystal not being warm, it still has the same issues. The only difference is that the crystal now also stops functioning when it gets hot enough... (>65C)
Since the 25 years between this device got manufactured I assume a bunch has changed in the world of crystals and maybe its original crystal has a higher load capacitance.
The circuit being used is as follows:
The MCU in question is an MC68HC05E1 which the datasheet can be found for over here: https://www.nxp.com/docs/en/data-sheet/HC05E1GRS.pdf
- What would the Load Capacitance of the crystal be like?
- What does it tell about the circuit when a crystal will only work at a certain temperature?