Yamaha DSP-AX1 10-Channel Amplifier - Answered Questions & Fixed issues

Look very closely at each capacitor to see if any has a burned look or if any shows signs of swelling. If any show these signs they probably need replaced. You should note exactly how you remove a capacitor from the circuit. To test them effectively they need removed from the circuit board. There are several different types of capacitors. If any look like a small can, this will be a canister type and most likely will be what is called polarized. These should have a line running down the side and will have a negative ( - ) sign on them. This capacitor must be replaced exactly the way they were taken out of the circuit with the neg line in the correct place. They must also be replaced with the correct size and value. The number of the value will be on the side followed with what looks like a U with an extra line on the left side. This will be the microfared value. An example is 1000uf. Also listed will be the max voltage the cap can carry, example 250v. The other types of capacitors are ceramic. They can be put back into the circuit either direction. The most important thing to remember is to replace with the correct microfared value, the correct voltage listed and the correct size. Before you start removing any electronic component from the circuit, turn the circuit board over and examine the solder joints. Each joint should be smooth and shiny. If you find one that has pits in the solder then you may have what is called a cold splice. This type of joint may be heating up during operation and the solder melting away from the wire on the capacitor and may run back to the wire after the power is removed, causing a small amount of contact until it is heated again, then the cycle repeat's self. If you find any joint that remotely looks like a cold splice, reheat them with a solder pen and recheck your device, you may have corrected the problem. It is kinda rare for capacitors to go bad but sometimes they do. I hope this helps you.

The fact that sound appears at max volume means that it is getting past and through the pre-amp stage. So it would appear to be in the main power amp stage the problem. It would depend what drives the channel, but if it's transistor driven I would suspect one of them.

Check the output transistors for leak.

Generally speaking, an amp attempts to protect itself from heat, shorts, overloads and operator exuberance by refusing to turn on or stay on.

Overloads can be from excessive periods of high output or marginally low impedance loading by the speakers; and shorts would be wiring issues or a speaker blowing up.

You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.

If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.

If it protects immediately on a cool power up you should disconnect the speaker connections and try it 'nekkid'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.

Check for loose speaker connections at the speaker as another possible root cause for intermittent shutdown.

Is this new equipment or a new problem on working equipment?

Register and download the manual for free at retrevo.com http://www.retrevo.com/support/Yamaha-DSP-AX1-Amps-manual/id/319bh827/t/2/ See Troubleshooting Page 79 Impedance Selector in between settings

Generally speaking, an amp protects itself from heat, shorts, overloads and operator exuberance by refusing to turn on or stay on.

Overloads can be from excessive periods of high output or marginally low impedance loading by the speakers; and shorts would be wiring issues or a speaker blowing up.

You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.

If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.

If it protects immediately on a cool power up you should disconnect the speaker connections and try it 'naked'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.

Are all the speakers turned off (set to None) in the speaker menu.(except the sub)?

2 channel direct analog stereo may still work, but any surround modes will use the speaker settings and the full DSP digital section.

Check also the input mode isn't incorrect - although if the sub is wired correctly and gives sound this can't be whats wrong.

Sounds like the protection relay for the speakers constantly activating,indicating either a short circuit or high bias current on the amp power supply. A qualified tech would be able to say easily with the right gear

HI...
That's the protect circuit kicking in.
The rec'r will require service. Either a couple of power supply capacitors have gone bad or one of the power amp modules has quit.

Many of these amps have a thermal fuse in the power transformer

get a tech to check for a primary connection on the transformer

There also may be fuses on the output of the transformer as well

I have one like it in my shop

The main power transformer has gone bad

Yamaha has them in stock

My bet is a faulty electrolytic capacitor! Don't know which. but would look around the circuit of those stages.

This could be a defect in the metering circuit. In order to verify this, you should measure the output externally. Get that external measurement and post the results here. We'll continue from there.

Dan

Works great after this solution with the cables.

Thanks

apply a good contact cleaner in this button and press it many times.confirm good connection between amplifier output and speaker b.connect speaker A insted of speaker B if it is working the problem will be in cabel and speaker B if not the problem in your amp output stage.

disconnect the cabel of left channel from your amp disconnect the cabel of right channel and put it in place of left channel if the problem goen your problem is in left speaker itself (cabel or speaker).if the problem excit the problem will be in amplifier output stage

Hello amos78

First, perform a visual inspection at the back of the unit and verify that speaker wires are not loose or shorting out with another connection. Find the impedance selector switch and verify that it is set to the proper position according to your speakers' impedance. It has to be all the way up or down, never in the middle. (Warning: Do not move the impedance selector while the receiver is powered. Make sure power is OFF on in standby, otherwise receiver will be damaged). Try power ON.

If these actions do not cure the problem, disconnect all speakers and try power ON again.
If the unit powers on, it is possible that one or more of your speakers or wires are damaged.
If none of the above actions fixes the problem, it is very possible that the receiver's internal circuitry is damaged.

Hope this helps you. Let me know.

cancerags

Just throw it away and buy a new one.

If your amp is less than 5 years old you maybe able to get it fixed for free at http://www.domgen.com check it out we have all our contents covered. This is better than your normal home insurance. Don't matter you could claim 100 times and never loose out. check it out! Also don't 4get to leave me feedback cheers raverbaby01

does the speaker relays work?

"Opening" ... Please explain what you mean.