JVC A-X900 power on but front panel no light

[Lynyrd]

Hello.
Need help for JVC A-X900 Amplifier.
Amplifier power on,but no front panel light.
No relay click.
It was 2 resistors blown R403 and R327.
After replacing no change.
We're I need control the voltages for front panel.
Regards.

SM
https://elektrotanya.com/jvc_a-x900b.pdf/download.html

 

[huggygood]

I'm sorry but we're not going to troubleshoot all your amps, it would be a bit too easy, do a little research on your own and come back to us if you really can't find it.

 

[adason]

Hello.
Need help for JVC A-X900 Amplifier.
Amplifier power on,but no front panel light.
No relay click.
It was 2 resistors blown R403 and R327.
After replacing no change.
We're I need control the voltages for front panel.
Regards.

SM
https://elektrotanya.com/jvc_a-x900b.pdf/download.html

Have you measured output transistors?
Resistors burn for a reason, and are rarely the reason why they burn. Typicaly something else caused excessive current to run through.
Do the homework, come back.

 

[Lynyrd]

All 4 power transistors desoldered and tested with transistor tester.
All 4 are ok

 

[Lynyrd]

R451 was blown.
After replacing front panel lighting on.

 

[Lynyrd]

Normally led protect blinking after power on.
After few second.....fix,but no led protect blinking

 

[Lynyrd]

Power transistors desoldered and tested ok.
Without power transistors

Q513
E.....-57v
C......-65v
B....-62.5v

Q511

E....-57.2v
C.....+65.6v
B.........-59.0v


Second channel with power transistors

Q512

E........0v
C........+65.5v
B.......0v


Q514

E.....0v
C......-65.2v
B.....0v

 

[Lynyrd]

R527...R529....ok

 

[Lynyrd]

Hello.
the amplifier works, there is sound on two channels, but if I touch the volume button, it goes into protection. Same if I press the button SUBSONIC.
With or without speakers goes into PROTECT. The voltage on the wires 2 and 5 of FW504 connector rises 2....4v when I turn the volume up.
Thanks

 

[Lynyrd]

Its work.
R404 was bad