Kyocera receiver not remembering stations
in [Repair]
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From: PeterD on 21 Apr 2010 19:34 On Wed, 21 Apr 2010 16:10:40 -0400, Meat Plow wrote: >On Wed, 21 Apr 2010 12:46:35 -0700, David Nebenzahl ><nobody(a)but.us.chickens>wrote: > >>On 4/21/2010 12:40 PM Meat Plow spake thus: >> >>> On Wed, 21 Apr 2010 12:18:03 -0700, David Nebenzahl >>> <nobody(a)but.us.chickens>wrote: >>> >>>> Question is about a Kyocera R-851 receiver, ca. 1985, 85 >>>> w./channel. Unit is in fine condition (many capacitators have been >>>> replaced) except for one thing: it doesn't remember radio stations. >>>> >>>> >>>> This receiver has 7 "presets" each for AM and FM. These can be set, >>>> and the unit will remember them so long as the power is on. Leave >>>> it overnight and the settings are gone. >>>> >>>> I'm ASSuming that these are stored in memory that may have battery >>>> backing. Opening the unit reveals no such battery/cell. >>>> >>>> Does anyone know enough about this unit to tell me what the likely >>>> culprit is here? Any links to schematics? >>>> >>>> Any help would be much appreciated. >>> >>> Well that's why, the battery is missing! >> >>D'oh! I knew it. >> >>Alright, now, any *serious* answers? > > >Sorry couldn't help myself. A schematic would help find what >keeps the volatile RAM powered up during off time or power failures. > >A "super cap" may not last long in 1985 circuitry. They tended to use >rechargable nicads back then like the 3.3v button cell battery pack I >just replaced in a mid-80's Peavey guitar effects processor that loads >into writable memory a patch list pulled from NVRAM when reset to >factory patches. > >Get some light and inspect it closely if you haven't. It may have a >super cap depending on how long they designed it to be powered down. Also look for a square/rectangular box like thing, about 3/4" x 1 inch usually black in color.
From: Cydrome Leader on 3 May 2010 15:35 In sci.electronics.repair William R. Walsh <wm_walsh(a)hotmail.com> wrote: > Hi! > >> Does anyone know enough about this unit to tell me what the likely >> culprit is here? Any links to schematics? > > Well, I'd wonder if there is a battery compartment on the unit > anywhere. Not trying to be disrespectful or anything, just saying that > a lot of older equipment used conventional batteries (AA/AAA cells) to > keep the memory running. > > I have a Pioneer SX-5 stereo receiver that uses two AA batteries. > Lifetime seems to be around a year or so. > > William hillarious. I was just about to mention that stereo when AA batteries were mentioned. do you know what the weird "AM stereo" RCA jack on the back is for?
From: Cydrome Leader on 3 May 2010 15:37 William R. Walsh <wm_walsh(a)hotmail.com> wrote: > Hi! > >> A "super cap" may not last long in 1985 circuitry. > > Dunno. I've got a Fisher tuner based on a Toshiba chipset (a 4-bit > microcontroller with integrated memory and a separate display driver) > that uses a supercap to keep the memory running. Does is seem pretty common for those older supercaps to leak what looks like machine oil?
From: William Sommerwerck on 3 May 2010 17:33
> Do you know what the weird "AM stereo" RCA jack > on the back is for? It's likely for a stereo AM adapter. |