Problem with my Yamaha DSP-A1

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Hi,

I have my trusted old Yamaha DSP-A1 which is probably about 10yrs old now.. Anyway recently in about 2 out of 5 times, whenver i turn the thing on, it takes out everything in the room electrical.. My TV flickers off, my light flickers off, and rather annoyingly it freaks my switch out. I've moved it off to it's own plug on a different circuit and it still does it.. Outside of this really annoying problem, its an awsome amp, it cost me 1,700GBP back in the day and still outperforms anything that i've heard in recent times, so i'd be reluctant to swap it out for a much cheaper replacement.

Anyone know anything about electronics or amps that have have some valuable insight? Any input is appreciated.

Thanks
 
Nice amp.

I would crack it open and check for shorts. It's probably pretty dusty inside. Give it a clean. Check the wiring on the plug. Does it do this if nothing else is connected to it?
 
When you say turn on, do you mean at the wall or the standby button? The fact it's 2 out of 5 times leads me to believe it would more likely be something like a damaged or loose cable/wire or dry joint. If it was every time then I would also suspect a faulty component.
The fact it's a power issue means you have to start fault finding from the mains cable to the amp. Use a multimeter to check the cables integrity and continuity, including any connections where it enters the amp. Then look for any loose/damaged wiring that may be shorting on something it shouldn't (like the case). After this check for any dry joints, there may well be a loose cable because of a dry joint. Last of all check for any obviously damaged components.
If you get this far without finding the cause then it's time to start checking out individual components and this is where a circuit diagram comes in handy (however it's not a necessity). The A1 has it's own protection circuit, so in theory if the fault is further down the line than where the circuit is, then the amp would turn itself off without tripping the mains. If you did then get it to power on then you could check it's diagnostics for a code to see where the fault is. Also worth noting is that apparently the relays used can sometimes suffer from oxidised contacts after 10 years or so, which would cause the amp to turn itself off intermittantly. However the fact your amp trips the mains leads me to believe the fault is preceding this circuit.
 
When you say turn on, do you mean at the wall or the standby button? The fact it's 2 out of 5 times leads me to believe it would more likely be something like a damaged or loose cable/wire or dry joint. If it was every time then I would also suspect a faulty component.
The fact it's a power issue means you have to start fault finding from the mains cable to the amp. Use a multimeter to check the cables integrity and continuity, including any connections where it enters the amp. Then look for any loose/damaged wiring that may be shorting on something it shouldn't (like the case). After this check for any dry joints, there may well be a loose cable because of a dry joint. Last of all check for any obviously damaged components.
If you get this far without finding the cause then it's time to start checking out individual components and this is where a circuit diagram comes in handy (however it's not a necessity). The A1 has it's own protection circuit, so in theory if the fault is further down the line than where the circuit is, then the amp would turn itself off without tripping the mains. If you did then get it to power on then you could check it's diagnostics for a code to see where the fault is. Also worth noting is that apparently the relays used can sometimes suffer from oxidised contacts after 10 years or so, which would cause the amp to turn itself off intermittantly. However the fact your amp trips the mains leads me to believe the fault is preceding this circuit.

Thanks for all your help.. I'm hoping fingers crossed I've found the problem.. At the back of the amp i noticed that i have a speaker cable that is without it's protective casing. I also noticed that i had a loose unused component lead from an old disused dvd player just sitting on it, metal to metal.. I removed it and turned it on and off a good 10times and not so much as a flicker.. So hopefully my old trusty DSP-A1 will give me another good 10yrs of joy !!!! I shall be keeping my fingers crossed that this is the issue though... But thanks for your help.
 
Thanks for all your help.. I'm hoping fingers crossed I've found the problem.. At the back of the amp i noticed that i have a speaker cable that is without it's protective casing. I also noticed that i had a loose unused component lead from an old disused dvd player just sitting on it, metal to metal.. I removed it and turned it on and off a good 10times and not so much as a flicker.. So hopefully my old trusty DSP-A1 will give me another good 10yrs of joy !!!! I shall be keeping my fingers crossed that this is the issue though... But thanks for your help.


Booooolacks, it done it again this morning.. so the problem still exists. Looks like i'll have to lug the beast out of its resting place and see if there's anything obvious.. Aside from chipping the odd PS1 back in the day, i've not had too much experience at fiddling around with circuit boards at component level, so i'm not holding out too much. Wish me luck !
 
Consider it wished, you could just pay someone else to repair it if you can't see anything too obvious. I'm guessing it would be a tad expensive though.
 
I own an AX1 and love it for the reasons you've mentioned.

Yeah, i'd look for dry joints. This range of Yam amps were built like battleships so hopefully it's just one small isolated problem.

TBH, even if it costs a bit to repair i would still consider it since it performs so well even compared to super duper "9.2THXultrahdmi monsters2. :D

Hope you get it sorted matey! :)

gt
 
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