PDA

View Full Version : Yamaha T-80 pre-set memory problem


recycler27
09-22-2008, 08:42 AM
I have a nice Yamaha T-80 digital tuner. In recent months it has not been retaining preset stations. If I don't turn it on every day or so, the memory goes away, even though the unit is plugged into an outlet.

I located a copy of the service manual, but couldn't find anything in it that deals with pre-set memory adjustment or repair.

I have taken a look inside and can't identify anything that looks like a battery. I seem to recall (I still have some personal memory function) reading a posting several months ago that claims that a capacitor is involved with memory storage, and replacing the cap restores the memory. Does anyone know how the memory works on the T-80, and how to repair it? :scratch2: Thanks, Doug

Pavioni
09-22-2008, 10:56 AM
aqua-green NEC FZ cap= 5.5v, 0.047f, 14mm diameter x 12mm height.

You can't miss that color on the board.

bastek
09-22-2008, 08:51 PM
Make sure the solder under that cap is not dry or cracked.

OvenMaster
09-22-2008, 10:19 PM
As Pavioni says, that short, squat cap needs to be replaced. I did that and my preset problem vanished (thanks again, Walker! :thmbsp: ). Total time with desoldering braid: 15 minutes.
Tom

recycler27
09-23-2008, 07:13 AM
I opened the T-80 last night, and immediately found the aqua-green cap :yes: that Pavioni identified. Looking on the other side of the circuit board, the soldering connections looked fine (thanks, Bastek). It would be easy to remove and replace this cap, even for a fledgling solderer like me.

However, I couldn't locate a replacement cap on Parts Express. I couldn't find anything even close to a 47,000uF, 5.5v cap. Probably because I'm not providing the right information on the website? So many caps, so little understanding.

So perhaps one of you can tell me what a suitable replacement is? Many thanks, Doug

OvenMaster
09-25-2008, 09:46 PM
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=604-1008-ND

recycler27
10-04-2008, 02:54 PM
Thanks to accurate advice here about repairing the T-80, I have a fully operational digital tuner again. I followed EchoWar's advice, which is always a safe bet, and ordered the correct replacement cap from Digi-Key. They mailed the part to me very quickly. I took a deep breath and plugged in the soldering iron, focusing my recently acquired skills on the task. I know that for some of you, replacing a cap is as easy as falling asleep after barbecue ribs and beer. For me, it was a whole new thing. It went fairly smoothly, thanks to solder braid and paying attention to the work at hand.

The tuner now remembers numbers much better than I do. I had forgotten what a nice-sounding and good-tuning device the T-80 is. I still prefer some of my analog tuners, but I consider the T-80 to be one of the better values among digital tuners out there. I like vintage Yamaha components more and more.

Thanks to all who gave information and advice. AudioKarma rocks!