Re: Yamaha R3 losing stored channels

From: Rob Haughey (peng001_at_hotmail.com)
Date: 06/20/04 

Date: Mon, 21 Jun 2004 08:57:28 +1200

I've now replaced the backup capacitor (super cap) and the unit is working a treat.
Thanks for your advice Mark,
Rob

"Mark D. Zacharias" wrote:

> The backup capacitor is bad. It looks like a "button" and is near the main
> micro IC on the main board, if memory serves. Yamaha still stocks a
> replacement.
>
> This model takes rather more effort to get into than many receivers. The
> average DIY type or non-tech would likely have a problem with this one.
>
> Mark Z.
>
> --
> Please reply only to Group. I regret this is necessary. Viruses and spam
> have rendered my regular e-mail address useless.
>
> "Rob" <peng001@hotmail.com> wrote in message
> news:40D0E48F.1E1468C6@hotmail.com...
> > My Yamaha R3 receiver loses it's stored AM/FM channels when power switch
> is off for
> > more than a few minutes.
> > The power switch directly switches all mains power in the unit, i.e.,
> there is no
> > standby supply to any circuits.
> > I cannot see any internal battery.
> > I therefore think the problem is a faulty memory device LC7030 or a faulty
> > capacitor.
> >
> > Do they use caps (electro) for memory retention?
> >
> > The user manual states that the Receiver may lose it's stored channels
> when
> > *unplugged* for a long time. As far as I can tell being switched off is
> equivalent
> > to being unplugged.
> >
> > I would like to understand the circuit around this LC7030 device which
> appears to be
> > where the channels get stored. Does anyone have a R3 circuit diagram or
> data***
> > for Sanyo LC7030.
> >
> > Thanks for any advice.
> >