Yamaha CA-800 Channel Out.

[HomerJSimpson]

I replaced the micro switches, and relay.

I am getting noise when I power on.

asking the relay engages immediately at power on.

 

[avionic]

I replaced the micro switches, and relay.

I am getting noise when I power on.

asking the relay engages immediately at power on.

Relay driver may be shorted. TR708..

 

[HomerJSimpson]

Which on is the relay driver?

 

[avionic]

. TR708..

 

[avionic]

2SA682--- Onsemi MJE253G
http://www.mouser.com/ProductDetail...=sGAEpiMZZMshyDBzk1/Wi/PUgtclNldlXeYTORofzOQ=

 

[HomerJSimpson]

I'll pull it and test it.

 

[avionic]

I'll pull it and test it.

Its either that or you have a solder bridge.

 

[avionic]

Check TR709 as well.If its shorted C-B it will instantly energize the relay at power on.

 

[HomerJSimpson]

I'll pull it and test it.

Tests good

 

[HomerJSimpson]

N

Its either that or you have a solder bridge.

None that I see, plus no work other than relay has been done.

 

[avionic]

Check TR709 as well.If its shorted C-B it will instantly energize the relay at power on.

 

[HomerJSimpson]

R714 looks like it got hot.

 

[HomerJSimpson]

Check TR709 as well.If its shorted C-E it will instantly energize the relay at power on.

Tests good in circuit.

 

[avionic]

N
None that I see, plus no work other than relay has been done.

Photo of solder side beneath the protect circuitry..

 

[HomerJSimpson]

D708 tests suspect in circuit.

 

[avionic]

Did you replace C714 ?

 

[HomerJSimpson]

Photo of solder side beneath the protect circuitry..

See pic.

 

[avionic]

D708 tests suspect in circuit.

Flyback diode your measuring resistance across the relay coil.

 

[avionic]

See pic.

Clean that board up with alcohol or acetone.. I can't see anything with all that flux residue.

 

[HomerJSimpson]

Did you replace C714 ?

No