Hi, The blue light temporarily comes on like it is going into protect mode and then shuts off. I do not hear the relay click. I measured the input voltage and it is at 12v and when the power is switched on the input voltage drops to approx. 5.5 volts. Any suggestions? Thanks, DN

This symptom is most likely due to RLY1 (protection relay) not coming on. The purpose of this relay is to give some time for the circuits to settle during power up to avoid a "pop" noise as well as to detect DC in the output that may cause damage to the speaker. If there is a fault condition, this relay may stay off so there will be no sound. Note that the LED indicator for auto on/off is not driven by this relay so that is why you get an indication of signal even though you have no output. If you don't hear the relay click on, this may be the problem. It may also click on and off again.

One quick thing to try is to have music playing into the unit before you power it on. Power it on for 1 second and then power off and see if you hear any output, even for a short time. This tells us that the speaker and amplifier may be OK, but the power supply is having problems.

You need a VOM to check the following: (all measurements are referenced to ground) (speaker does not need to be connected) (be careful of the mains supply voltages)
1. Check to make sure you have around 50Vdc at cathode of D10 (side with the painted line on the case of the diode). This is the power supply to the relay.
2. Check connector CN2 and make sure you have +/-15V. The center of the connector is ground and this is a 3 pin connector, so each side will be a rail voltage. If either voltage is not close to +15 or -15, the relay may not come on.
3. Check anode side of D9. This should be close to 0V if the unit is normal, and close to 50Vdc if the unit is in protect mode.

If the unit is in protect mode and 1 and 2 look normal, the power amplifier has DC and is most likely damaged and will need some expertise to repair. If all seems normal and there is no output, the speaker may be burnt out. You can put the VOM in ohmmeter mode at the lowest ohm setting and measure the resistance of the voice coil which should measure below 10 ohms and above 2 ohms. When connected to the meter, slightly push on the cone and you should see the measurement change value slightly indicating that the speaker is probably not at fault.

If 1 above is normal, but 2 is not, look up (on FIXYA) how to fix this model when it cuts out at high levels as this fix should also work. If after applying this fix, the rails are not the correct voltage, you may need to replace either of the regulators U14 or U15.

Trouble shooting is the only way to approach this problem, but is you stick with it, you should have enough information to pinpoint the problem which will lead to the correct fix. Good luck.

Yes that is why. The receiver is protecting itself from an un-stable load impedance which causes current/voltage spikes through the final amplifier components and proportionally through the input where the protection relay is (click),. Do not continue using the amp until you have repaired or replaced the blown speakers. A rule of thumb is to maintain 8 ohms on each speaker wire plugged into the amp. Keep that in mind or eventually you will damage it.

THe clicking you are hearing is the relay that is being activated byt he protection circuit. See the link below for an explanation of protect mode.

In your specific case, I'd be looking for a potential heat problem or for frayed wires to the speakers that may be shorting out the speaker lines. This can show up as "low impedance" to the amp and make it work extra hard, generating extra heat etc...

Please post any additional questions here.

Thanks,
Dan

Link: http://www.fixya.com/support/r5390728-protector_means

The relay or relays that click disconnect the receiver from the speaker terminals so that no dc voltage can burn out the speakers. More than likely the power output transistor(s) are faulty. Look at the relay(s), determine the input and output connections. The inputs come from the output power transistor and emitter resistors area, the output of the relay(s) connect to the speaker terminals. Check for dc voltage on the input contacts in the range of 30-60 volts possibly. If dc voltage is found there then you have bad outputs, caps or emitter resistors. A word of caution -troubleshooting at this level requires advance knowlege of electronics, do not attempt this with out onsite help from a experience tech.

Sounds like you have a bad amp IC or transistors.
When these go bad they almost always put roughly 40 volts dc from the amp power supply to the speaker terminals. The protection circuit senses this dangerous (to your speakers) dc voltage and disconnects the speaker terminals from the amp via internal relays (the ones you hear click) and puts it into protect mode. If it didn't the dc voltage would quickly toast the voice coils of the connected speaker.

hi Matt Cowles
The problem that you are having is with the power relay. that is the clicking that you are hearing.
It's a protection measure. 
First thing i would check would be for possiblity of any shorted speaker wires (strands touching, either on speaker output jacks on the back of the receiver, or at the speakers themselves.

if this checks out ok, then some other possibilities are,

• Defective or dirty power switching relay.
• Cold solder joints on circuit board, or around jacks.
• defective power switch.
• Loose panel or ground screws on the input jacks on the back of the receiver
• possible shorted power output transistor (s)

If youre good with identifying cold solder joints and soldering , then giving everything inside a good look over may identify the trouble area. its impossible to pinpoint without actually being able to look at it.
If you arent comfortable with the soldering and inspection aspect, id recommend finding a shop that services yamaha components.
Hope this helps

Ok,

I will will help you with this, but you must follow my instructions. These are not easy unit to repair, and your troubleshooting technic may have even caused more problems. You should never power on a receiver with connectors unplugged. Since the 15 pin connector is used for the audio signals only (CN559) you may be OK, but please do not do this anymore unless you are willing to create a lot of smoke.

Since this unit does turn on without that one connector plugged in, I will assume that you do not have a blown channel even though it is the most common reason for these to go into "Protect Mode" which is what yours is doing. They go into protect mode to keep the receiver from causing more damage to the circuits and to prevent fires.

I think the most likely reason your unit is going into protect mode is because the negative 15 volt regulator on the main board is bad. This regulator is located by ref # IC102 and is on a small heat sink in the power supply area of the main amp board. Since you have the manual for this unit you should be able to find the part number and location very easy.

The second most likely reason for your problem is a resistor, ref # R184, it is a 10 ohm 1 watt resistor and it is right next to the pre-amp board on the main board. It is near CP501 but on the other side of the pre-amp board towards the output transistors a little. Check this resistor first with an ohm meter, see if it is at 10 ohms. If not, get a 10 ohm 1 watt flameproof resistor and replace it. Then make sure everything is plugged in right and try it again.

If the resistor is good, then go to the voltage regulator, you can check it by measuring the voltage at resistors R145 and R146. If you look at the schematic for that area, you will see that those resistors are connected to both the positive 15 regulator and the negative 15 volt regulator. One side of R146 should measure -15 volts and the other side of R146 should be at 0 volts. Then measure R145. You should have +15 volts on one side and 0 volts on the other side. If the voltage you measure there is not within a couple of tenths of a volt either way, change the voltage regulator that is bad. If all you get is positive voltage on R146 and no negative voltage, then IC102.

Now you are probably wondering, how can you check those voltage if the unit is shutting off right away. Here is how. Have you meter probes in place before turn the unit on, watch the meter while is is turning on. You only need a few seconds to check each one. Check R146 first, then after the unit shuts off, check R145 when you turn it back on again. This is much safer than unplugging connectors and letting the amp idle with unbalanced voltages which could cause an extreme current draw if left on too long.

If you can not verify any problems with those two things above, then you really do need to check the amp circuits. You can do this with no power connected, but you must take out the main board with the big heat sink. Once you get it out, check the output transistors and start with the pair that is located at the inner most spot of the heat sink. The area close to the display and CNT board. That is the most common channel to go bad. If either one of those transistors mounted on the big heat sink measures shorted of very low in ohms, that is the bad channel. If you have a bad channel, there will be many more parts to replace, I will let you knwo what those are if you find any shorted output transistors. You can not check the amp circuit any other way, you will only be getting a reading across the relays if you try to check it at the speaker outputs. The speaker relays never open unless the unit comes out of protect mode first.

Let me know if I have explained this good enough for you, if not I will give it another try.

Good luck,
Dave

Unit is going into protection mode because the amplifier output stage is shorted. Measure output voltage of the speaker lines coming out of each output channel...front/center/rear...take measurement before the channel speaker line protection relay. If any voltage is present then that is the output channel that is at fault. Replacement parts are available to the consumer through tritronicsinc.com. If you have experience with a volt meter\checking transistors\soldering it is something you can do. If not it should be left to a service shop. Have a great day!!

barneyluc

Contact Phoenix Gold at 800.950.1449

Sounds like a bad output channel is causing it to go into protect mode. Time to see a repair tech.