Disassembly of HP-19C

[Jonas Sandstedt]

Hello and thanks for all tips. The new solder indeed "blobs" on the joint, and the joint won't melt to be sucked away bý either vacuum pump or desolder wick. The solder joints are most surely oxidized, having been rinsed from battery leakage with vinegar acid. Is there any other way to melt these joints without destroying PCB and components? Perhaps the safest way to continue is to try to re-assemble the calcualtor and see how it works before working more on the PCB.
best regards, Jonas