Yamaha MX 1000

iliyanG

New Member
Hello, a week ago I bought a damaged Yamaha MX1000. There was damaged end steps. The first owner tried to repair it but twice it exploded. As I opened it there were defects on the main board. Transistors number Q513 Q514 Q515, as well as resistors with numbers R531, R532, R533, R534, R583, R584. Besides these there were damaged resistors that will surround the picture below. If anyone can write, what are the resistors of the resistors listed by me. The problem is that this circuit, which I have the MX 1000 / U and many of the elements do not respond, even absent R583 and R584 are not in the schematic. Hope you understand what I'm writing because I'm translating with Google. I hope your help.
 

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OK, before you get to the resistors....

  • The reason schematic does not match the actuals is not because of U non- U version. It is because your serial number is E03..Or higher.
  • You will not be able to test the main board without the sub-boards attached or without some type of a load ( more on this on a separate thread from @amr2
  • Because so many people mingled in the unit thus far, it is safe to say that you will need to test all components of this amp. This is not an easy amp to repair, particularly at the stage it is in now. A highly recommend alternative is for you to take it to a specialist
  • If you decide to go forward, I suggested you get yourself a DBT and start researching this forum
I will try to dig up some notes on the values of those resistors, but it is not a guarantee I will find them . I am not close to a unit, so hopefully someone else can chime in.

More to come
 
Thank you once again for taking your time off.
When I took it was much worse. In this situation now works without heating the elements. The resistor readings are now 460 ohms. In the previous thread I wrote that they are 0.460. I had put 4 by 1 ohm, but immediately after switching on they heated many transistors Q513 Q514 gray big resistors between them. If more photos are needed, i can upload without problem
 
Not sure if you understood what rottalpha meant by DBT (dim bulb tester), but this is a picture of it.
You should not proceed until you've built one. Use it with a 75W or 100W incandescent bulb (old style, with fillament), so that the current is limited to the amp while you are testing.

This will stop you blowing new components each time you didn't fix something properly.
If 5 parts are damaged and you only find/replace 4, turning the amp on with full current may re-destroy all 4 new parts.
With current limiting you can avoid this situation. If there is a short, the bulb will glow bright instead of damaging large parts.

Have you tested the main output transistors?
The ones attached to the heatsink.

Your translations are perfectly understandable.
 
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Not sure if you understood what rottalpha meant by DBT (dim bulb tester), but this is a picture of it.
You should not proceed until you've built one. Use it with a 75W or 100W incandescent bulb (old style, with fillament), so that the current is limited to the amp while you are testing.

This will stop you blowing new components each time you didn't fix something properly.
If 5 parts are damaged and you only find/replace 4, turning the amp on with full current may re-destroy all 4 new parts.
With current limiting you can avoid this situation. If there is a short, the bulb will glow bright instead of damaging large parts.

Have you tested the main output transistors?
The ones attached to the heatsink.

Your translations are perfectly understandable.



Hello Zaibastu, thank you for the advice. I do not have such a device. I make them with a 75W lamp, which I connect to the main fuse. I do not know when it is wrong, whether the lamp should go out or shine lightly. The lamp is now a candle.
 
If there is a short circuit (mistake in your work, or major problem), the light will glow bright.
If there is no major problem, the light will be very dim (like a small candle).

If there are still some problems, the "protection" LED will remain lit, and the relay will not click when you have one of the speaker buttons engaged.

The goal is: power on, bulb starts bright, then dims, protection LED turns off (2-4 seconds after power on), and relay clicks (engages).
goal.png
 
If there is a short circuit (mistake in your work, or major problem), the light will glow bright.
If there is no major problem, the light will be very dim (like a small candle).

If there are still some problems, the "protection" LED will remain lit, and the relay will not click when you have one of the speaker buttons engaged.

The goal is: power on, bulb starts bright, then dims, protection LED turns off (2-4 seconds after power on), and relay clicks (engages).
View attachment 1147002


By turning on the amplifier, the lamp lights up like a candle without first lighting up. When I had mounted 1 ohm resistors, it was lightening first and then it went down and it remained as if it were a candle. The red light goes out after a few seconds and the relay sounds like you have explained it. I can take pictures if necessary.
 
By turning on the amplifier, the lamp lights up like a candle without first lighting up. When I had mounted 1 ohm resistors, it was lightening first and then it went down and it remained as if it were a candle. The red light goes out after a few seconds and the relay sounds like you have explained it. I can take pictures if necessary.
So you are saying the amp comes out of protection. That is good news.
For this amp a 75w bulb will glow brite as soon as you push the switch, then deems low
 
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Ok, I could not figure out just by turning on the amplifier, the lamp should be lit and then lowered. And what is Brite.Google does not translate it.
 
The bulb will shine brighter first.[/QUOTE


Hello amr2, thank you.
So, it must first shine first and then diminish. Do I understand that as it is now lit up to me is wrong. Because as I wrote above, turning on the amplifier shines like a candle. It was not the original strong lightening.
 
If I know what are the missing resistors in the circuit, I think the problem will be solved.

what are the resistor numers you are looking for?. I cannot make them out from your photos.
besides the four 1ohm resistors I mentioned earlier, all of the other replaced resistor values you are looking for, should all be in the the service manual parts list section, pages 16 and 17.
 
what are the resistor numers you are looking for?. I cannot make them out from your photos.
besides the four 1ohm resistors I mentioned earlier, all of the other replaced resistor values you are looking for, should all be in the the service manual parts list section, pages 16 and 17.


Hello, resistors with numbers R583 R584 and the four behind the green capacitors 820 uF 100V.
 
I see you did not yet replaced the capacitors. I sugest you replace the small blackgates. They are most likely way out of spec.
 
The available circuitry R583 and R584 are absent. The four resistors behind the two capacitors are also not indicated. They are represented as R547 and R548 if I'm not mistaken. There are only two.
 
I see you did not yet replaced the capacitors. I sugest you replace the small blackgates. They are most likely way out of spec.

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59/5000
Shte bŭdat zameneni,kakto i vsichki elektrolitni kondenzatori.
They will be replaced as well as all electrolytic capacitors.
 
Hello, resistors with numbers R583 R584 and the four behind the green capacitors 820 uF 100V.
the four beyound the 820uf caps are all 1ohm, as I already mentioned to you.

R583, 584, I cannot make out of the photos I have and I am not near a unit anytime soon. Someone else in the forum that has a unit with serial number E03 and above, will have to physically look them up for you
 
the four beyound the 820uf caps are all 1ohm, as I already mentioned to you.

R583, 584, I cannot make out of the photos I have and I am not near a unit anytime soon. Someone else in the forum that has a unit with serial number E03 and above, will have to physically look them up for you
Yes, I hope someone who has the same amplifier to write the values of the resistors.
 
what makes you think that R583 and R584 were not replaced with the correct values?
looking at other replaced resistors such as R533, 534 which are suposed to be 100ohm, it looks like they were replaced correctly
 
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