NAD 4150 tuner

[Richard]

Hi, I have a problem in that when the tuner is off for a period of time it
will lose its station presets. I do not have a schematic on this unit, can
anyone tell me which chip stores this infomation?

Thank You
Richard Foy

 

[David]

How long of time before it loses information? Days, weeks?
Check for either a lithium battery or memory back up capacitor near the
system control circuitry. Either one failing can cause the symptoms you
described.

Usually the memory back up capacitor is good for a couple of weeks of the
unit being turned off.

David

Richard <rfoy@hotmail.com> wrote in message
news:vo0l6cafn5154b@corp.supernews.com...

Hi, I have a problem in that when the tuner is off for a period of time it
will lose its station presets. I do not have a schematic on this unit, can
anyone tell me which chip stores this infomation?

Thank You
Richard Foy

 

[Tim Schwartz]

Richard,

Look for a memory cap around the tuner controller IC, IC301(TC9137P).
The schematic I've got is near impossible to read but I think it is
C311, a 4700uF, 6.3 Volt electrolytic. You want a low leakage type, so
I would suggest buying a new one, not going to the junk box. Also, if
MY memory serves, they only hold memory for a few weeks if not turned
on.

Regards,
Tim Schwartz
Bristol Electronics


Richard wrote:

Hi, I have a problem in that when the tuner is off for a period of time it
will lose its station presets. I do not have a schematic on this unit, can
anyone tell me which chip stores this infomation?

Thank You
Richard Foy