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Leyland AM/FM Car radio - no FM

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Technotronic
Technotronic picture

This radio is to a 1970's MG/MGB vehicle. Its using an older 14 Pin DIP IC to
do the FM stuff, its marked T2D. Cross ref comes to a NTE723.

If I put my metal probe on pin 9 or 10 (detector) I can hear a local FM station playing,
but the tuning has no effect.

I have 100 ohms from pin 9 or 10 to gnd. Pin 3 is seen directly tied to gnd, and pin 4 also reads short to gnd
and there is no DC volts on it also no dc volts on pin 5. I can see no dc volts on any pin I probe. Is the IC bad?

Its not getting warm for short and current draw on the PS is minimal.

 

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Technotronic
Technotronic picture

More info, found out the IC has many different subs:

SK3144, CA3075, CA3075E, CI-1003, ECG723, GEIC-15, IC309(ELCOM), LM3075, LM3075A, LM3075N, MC1375P, MC1375PQ, R2516, SFC6032, SL23648, SN76675N, T2D, T2G, T2G(I.C.), T2G(IC), U6A7075354, U9A7075394, UA3075, UA3075PC, ULN2129, ULN2129N

 

I see what looks like a solder splash between pin 3 and 4....bonding the gnd to the Zener regulator. Perhaps this is why the VCC pin seems loaded down...

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