hello friends.
I have problems with MTX RT251D
The last week the sound was dirty, I measure all components and I changed Q110 (was leak) and the sound was clean again.
But after a few hours of use the sound is like shorted.
All the components in the amplifier appear be fine, but the voltage in the center legs of the rectifiers are just + - 9v
there are the voltages on TL494
1 0.09
2 4.6
3 0.06
4 3.9
5 1.5
6 3.4
7 0.02
8 11.7
9 0.007
10 0.007
11 11.8
12 11.8
13 5
14 5
15 5
16 0.008
I have problems with MTX RT251D
The last week the sound was dirty, I measure all components and I changed Q110 (was leak) and the sound was clean again.
But after a few hours of use the sound is like shorted.
All the components in the amplifier appear be fine, but the voltage in the center legs of the rectifiers are just + - 9v
there are the voltages on TL494
1 0.09
2 4.6
3 0.06
4 3.9
5 1.5
6 3.4
7 0.02
8 11.7
9 0.007
10 0.007
11 11.8
12 11.8
13 5
14 5
15 5
16 0.008
12.2 v applied in the positive and remote, no audio and no speakers connected.
LM339
1 7.3
2 10.8
3 11.6
4 0.78
5 3.8
6 1.28
7 3.8
8 3.6
9 5.3
10 5.3
11 7.5
12 0.00
13 7.4
14 7.4
LM339
1 7.3
2 10.8
3 11.6
4 0.78
5 3.8
6 1.28
7 3.8
8 3.6
9 5.3
10 5.3
11 7.5
12 0.00
13 7.4
14 7.4
I don't see a problem with the input voltages to that IC. Is there a PNP transistor with its collector connected to pin 4 of the TL494?
If so, lift it and see if the amp will power up. Be careful because this will defeat the protection circuit. The remote on/off may not work so be prepared to disconnect B+ in case there is a problem.
Does the amp power up and produce clean audio?
If so, lift it and see if the amp will power up. Be careful because this will defeat the protection circuit. The remote on/off may not work so be prepared to disconnect B+ in case there is a problem.
Does the amp power up and produce clean audio?
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