HA3500 HARTKE cut-off

[cyrilbcyril]

I've got an old HA3500 which cuts off if I turn the power too much. After opening, it looks like the protection IC from Toshiba open the relay for an unknow reason. It doesn't look like it is due to an overtemp, since the heatsinks seems quite cold before the cut-off. Just before the cut-off, there are some clicks happening. I have no clue what it could be, if someone could give me some ideas or history ( maybe the toshiba IC does not work properly anymore ?), it woul be great!

Thanks !
Cyril.