These parts provide serial_to_parallel shift register with output latches. Each output may sink up to 50V/350mA.

Ok, and at what temperature will be the die then, when 350mA are sinked?
Also, 350mA specification refers to an ambient temperature of 25°C, but Mahmood is living in Jordania. And, there are 374 other 'TPIC6A595' sitting arround. Means, I assume the 'TPIC6A595' were running at rather high die temperature, which is critical if high reliability is to be expected.

Kai