Diode tests mean nothing on opamps - unless it reads '0' in which case it's bad. You tell if they're working if the Voltages are where they should be. The '+' sets the DC reference point. The feedback network connected to the output and '-' input will attempt to force the '-' input to match the '+' input. Sometimes newbies set up impossible conditions that simply can not work but invariably you'll find large differences in the DC levels between the inputs and the output at one of the rails.
If the circuit WAS working and has now failed just change the amp. BTW opamps rarely fail unless abused.
The KIA4558 is just Korea Electronics version of the RC4558 or LM1458. The 'S' package is unusual. In the world of performance opamps it's pretty uninspired.
G²
hi, thanks for replay,
you right i put the stereo hi output to the amp low input and i burn it.
but i think that are this opamp because i test all the other transistors and are ok (i think)
the problem is that in the kia4559 that i take in a old amp with diod test all the pins have difference between .
in my kia4558s not all pins have the same difference.
but special 2 pieces show completely different value.
regards
you right i put the stereo hi output to the amp low input and i burn it.
but i think that are this opamp because i test all the other transistors and are ok (i think)
the problem is that in the kia4559 that i take in a old amp with diod test all the pins have difference between .
in my kia4558s not all pins have the same difference.
but special 2 pieces show completely different value.
regards
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