Quoted from Angyalpor:But, if I add solder, the old one drops it down. Looks like, they are incompatible, or something... I plan to de-solder all the pins, clean the board, and the hole on it, and re-solder the pins with my solder. Is it the good way to repair it?
Are you trying to use lead-free solder? Lead-free solder has a different melting temperature I believe. This older type of solder with which these boards were constructed with is supposed to be banned from sale in most European countries these days.
You'll need to get hold of some this older type electrical solder made from lead. Most of the older family run electrical/hardware shops will still have this type of solder in stock if you ask. You won't get it if you go to any of the modern electronics stores.
