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Yamaha DSP-A1 - Channels Failing

bigalxyz

Active Member
Hello forum,

I've got two (long story!) Yamaha DSP-A1s and I'm having the exact same problem with both. When I first switch them on, I often get no sound through the centre or surround channels (not sure about the mains because I use the pre-outs to send the signal to a separate stereo amp). In general I can fix this by turning the volume up high - the sound suddenly appears from the missing channels (one after the other), and continues to work ok when I turn the volume back down. They work fine until I switch the machine off, but as soon as I switch it back on again the problem usually reappears.

No scratchy sound when I adjust the volume so I'm guessing (?) that the volume pot is ok. Loud clunk sound when I turn the amp on and a second clunk a few seconds later (which is when the sound comes on) - are there some relays making that noise? Do relay switches get stuck?

It's not fatal but it's a nuisance. In particular, I'm hoping to sell one of them soon and it'll be much more attractive to buyers if I can fix this. Just wondering if anyone knows what the problem might be and whether or not it's an easy fix.

Grateful for any advice, suggestions, etc.

Thanks
Alan

(both also have the usual problem with dry solder joints on the PCB that the display is connected to, giving missing pixels, missing lines, etc. but I've resoldered everything on one amp - successfully - and I'll be doing the same on the other one soon :thumbsup: )
 
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bigalxyz

Active Member
Thank you. I fear however that given the age of these amps it's probably not economically viable to pay to have them repaired. I'd be happy to have a bash at a bit of DIY myself though (I'm fine with dismantling bits of kit, doing some soldering, etc.) but I guess before I do that I'm hoping to find someone "out there" who reads my message and says "oh that happened to me, it was a faulty thingywotsit, you can buy new ones for £1.50 on eBay"! (without that, I fear I am doomed to fail...)
 

Technot

Active Member
I have the Yamaha Ax1 which had a random dead speaker, it had a modification which was connecting the pre out phonos together as they were acting like they had phono cables connected which would turn off that particular speaker, my amp is ready for being replaced even though it’s still as new, there’s a lot to gain with Atmos and all the features we don’t have, I think it’ll be well over a £100 to inspect then parts and labour, not worth it imo
 

187umkillass

Novice Member
Hi,
I bought my A1 two yrs ago with fault as you described and to be honest its easy fix just follow the video:


99% its blown capacitor which results to damaging IC controller as well.
If you open it up focus on board with "Main output" and search for any blown or weird looking components on it.
Those capacitors could run till 10.000 hours so from 1998 they could have enough init?

Thats it.
By the way dont give it to any Yamaha stores they will charge you god knows how much and with these components you can fix it for 20-30 quids.
Parts are available on ebay i did get mine from there. Just right down the P/N.
I think capacitor used in A1 is ancient now and it was updated by diferent P/N but you can dig in google.

Good Luck
 

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