Yamaha AX - 596 Amplifier Repair (With Audio Tutorial)
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- Опубліковано 6 гру 2023
- Fault
Amplifier switching out of standby mode but start up relay not changing over.
Issue traced to broken tracks on the main Amplifier circuit board as shown in the video.
Link wire used to repair the issue, fixing the start-up fault.
Due to the age of the Amplifier the speaker protection relays were also replaced to fix an issue with intermittent sound loss due to worn and oxidised relay contacts.
Specifications 24 V DC Coil DP/CO Contacts.
User controls cleaned with De-Oxit
Amplifier fully tested working correctly. - Наука та технологія
Very interesting ! thank you
Hi, I wanted to ask you about the amplifier.
mine works but I don't have the bias measurement on the 4 2.22ohm 3w resistors, I measured them with the tester and they are good.
the cooling fins remain cold only the one on the left heats up after +/- 1 hour, the right remains lukewarm.
all measurements on the finals and various transistors are perfect as per S.Manual.
I'm not sure about this problem, do you have a suggestion?
sorry 0,22 ohm resistor
Hi the when referring to the service manual, the bias is measured at R111/R135 left channel and R112 / R136 it should be 0.4 to 8 millivolts.
If either is high cut resistor R175 left channel or R176 right channel.
thanks for the answer, the problem is that there is no measurement on the test point I have 0 mV this is the problem🤔
@abrambilla Hi as you are aware the bias is preset there is no trimmer to make any adjustments. If you are reading 0 volts it indicates no current is flowing through the emitter resistors.
I would check the emitter resistors and also the solder joints around that area of the circuit.
yes I saw that there is 0 volt emitter, 0.6v base and 52v collector on all 8 final transistors, all the measurements of the small transistors are perfect, I replaced the electrolytics except C107/108 220uf and C130/131 470uf and checked them all the resistance values.
I don't understand what I'm missing.
anyway, thank you@@AudioAmplifierServicing
hello, i have the same amplifier and i have an issue, it turns on and then gets out of standby mode and then the speaker protection relays do not click, during this time, the volume knob does not respond to the volume buttons being pressed for increasing/decreasing the level while the rest of the amplifier functions such as input selection and stand-by work via remote, any idea as to what could be wrong? thanks!
and one more thing, i did not understand how you did a check for the status output using a multimeter, if you could explain that to me it would be helpful,thanks!
Hi can you confirm the setting of the speaker selection switches.
The switches are behind the drop down flap. To check the output status with a multimeter connect, the negative multimeter lead to one of the negative speaker terminals and measure the voltage level with the positive multimeter lead.
@@AudioAmplifierServicing yes, the speaker selection switches, both A and B were "on"
i shall check the output status and get back!
@@AudioAmplifierServicing i did measure the voltage, on standby it is 1mv dc and when the amp is turned on it goes up to 1.2mv dc
@@waitingforthetrain2690 Hi as the Amplifier is not in protection mode, check the DC voltage supply for the relays.
Measure the voltage across C319 & C140 as detailed in the service manaul section Relay Drive.
@@AudioAmplifierServicinghello, i believe that on C139 and C140, the voltage should be 17.5 but on C139 i get 32v dc and on C140 i get no voltage