Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: polio on October 21, 2010, 06:13:14 AM

Title: Yamaha DG80-112
Post by: polio on October 21, 2010, 06:13:14 AM
Hi there, I have just bought this amp and there is a problem with it that I hope someone can help me with.
First of all the amp indicates E1 on the display after a short while when I change to a new sound but disapears when the recallbutton is pushed once again. This happens all the time but that problem  is something that I can live with and other users of this amp seems to experince the same and they ignore it to.

The other more serious problem is that all of a sudden all the controll knobs search their maximum positions and does not move even if change to another sound pattern. If I try to move the controll knobs they just move back to maximum again, the controll knobs are motorized. But here comes the very odd part, if I tapp a little more than gently on the back of the amp at the position where the "computer" card is inside of the amp is it can function as it should again.

Any ideas someone?
Title: Re: Yamaha DG80-112
Post by: J M Fahey on October 21, 2010, 08:34:52 AM
Open it under a good light, push-in connectors which may have come loose, whack it gently in different places with a chopstick or plastic pen, keep an eye on the display.
Clearly it's a "mechanical" problem.
Good luck.
Title: Re: Yamaha DG80-112
Post by: polio on October 21, 2010, 08:59:44 AM
Ok, I´ll try that, is there also any idea to use "computor"spray on the connectors?
Title: Re: Yamaha DG80-112
Post by: J M Fahey on October 21, 2010, 12:01:09 PM
Deoxit cleans dirty old worn connectors, but yours is too new for corrosion.
Wire bundles *may* have been pulled by mishandling during transport.
Title: Re: Yamaha DG80-112
Post by: polio on October 21, 2010, 03:06:21 PM
I have done just as recommended and after the problem was located  I also used some spray after I lifted the connectors from the card. I did the same with all of the connectors despite your advice and now it works flawless and  even the E1 does not appear on the display anymore either.

Thank you very much for your advice/ a guitarplayer from Sweden
Title: Re: Yamaha DG80-112
Post by: scooperman on October 21, 2010, 05:58:09 PM
The DG80 power supply circuit board is not well supported.  If the amplifier is dropped, the weight of the transformer and other heavy components will crack the circuit board.  Next time you have the amp apart, add some insulated standoffs/braces to the power board.
Title: Re: Yamaha DG80-112
Post by: polio on October 22, 2010, 03:00:42 AM
Ok, that´s a good advice, you seem to have some experience from these amps is there anything more that´s  good to know about it? How about the motorized knobs for example, is it possible to lubricate them in anyway? I think they might be a weak spot in the long run. I really want to look after it since it sounds really good once you get the hold of the sound opportunities.

Polio
Title: Re: Yamaha DG80-112
Post by: scooperman on October 22, 2010, 08:07:36 AM
I have not seen problems with the motorized pots.  I think that maybe this is because the pots are not usually being yanked around by human hands, instead they are usually moved smoothly by the motors.
Title: Re: Yamaha DG80-112
Post by: stchristopher on December 19, 2010, 07:56:43 PM
From memory I read you can also get the E1 error message when you turn the pots fully clockwise (10) or counter clockwise (0).