Enough to make you cry.

[Michael de Estrada]

(04-24-2018 04:12 PM)AndyWalter Wrote:  If someone has powered this up using the mains psu, without a battery pack in the back, it's possible the internal chips may be toast, no? I thought the batteries had to be present to prevent the psu over-voltaging the circuitry. Certainly is the case with my 29C, which I've been very careful never to do this to.

Even if a battery is installed, the calculator circuitry can be ruined if the battery is bad with high internal resistance or makes poor contact with the calculator terminals. My rule is to NEVER connect the AC adapter to the calculator, and recharge the batteries externally.