IN SEARCH OF: SVITA7317P speaker protection operation amplifier

[DrDos]

I have a Technics SA-404 reciever that has a bad IC chip TA73717P. I have purchased 4
off ebay and all of them instead of clamping at 3.2 volts on pin 9 they clamp at 0.7 which is
unexceptable. I have been almost everywhere and can only find the Chinese knockoffs.
I would appreciate any help in finding these or hooking me up with someone willing to sell one.
Thanks all.

 

[mbz]

Assume you've ruled out external (to the IC) power supply issues to pin 9.
You seem to be putting the low pin 9 voltage down to an abnormal IC current draw if I understand correctly

edit is the mute timing cap ok? leaky? Will dig up the sm...

 

[DrDos]

Well I just replaced the 2 non-polerized caps that are involved with the timing. The resistor that sends
the voltage is working great. I am supposed to have 3.2 at Pin 9 to clamp so the relay will open and all I get is 0.7.
So I have been getting nothing but chinese knockoffs. So today I found RF Parts in California. They have new old stock
of the TA7317P's so I ordered a few along with some zenars I needed. I really found no other problems after tracing
with any other component, I mean even with the IC out the pad was recieving the correct voltage so it had to be the IC.
There is something wrong with the diodes inside the fake ones clamping down at an improper voltage.
They are just so hard to come by, I mean real ones. Must have wasted 60 bucks on fakes.
Thanks for the thoughts on this but I bet it'll work with the new IC'. Cheers!