Re: PIC18F2550 Timer1 External Clock Source Crystal not running
I suspect these parts when assembled way back when might have used non RoHS Sn-Pb solder ~ 235C soldering point. Newer multilayer caps use much Pb free solders that are much higher temp. Back to your last comment, your 250C iron won't be a problem as long as you only touch for a second or so. Any longer than that might cause the ceramic to lead wire connection under the epoxy to melt.