Phoenix Gold ZX500 with high frequency noise

[TeleThunder]

Hi
I am new here, but have been lurking around for some time:)
I have a ZX500 that I put new railcaps on before powering it up to test it, everything seems to be fine, but then after some seconds I get some high frequency noise in the left channel speaker.. Amp still working, playing music but.. What can cause this, where and what to look for? This is inside amp and not from cd player..
Thanks

[zeropoint0.5]

my first thought would be it comes out of the crossover board...does it have a green quadpot in it??

those pots caused alot of trouble in the past......

but if you didn't have this noise before cap changing, maybe you did something else wrong.....

did you only replace the rail caps ? or did you mean you replaced the input caps....

the railcaps are the 2 big black ones.... the input caps are the 6 just behind the power terminal....

[TeleThunder]

Thanks for responding:)
Sorry, my bad..I am from Norway... I changed what you call inputcaps.
I did not put power on the amp before I changed caps, so it could have been like this before also. I do not think I messed up something else when I changed those caps, it was actualy an easy straigth forward job to do this. I am an electrician.
I will check those pots, I have already tried to clean them, dont remember the colour thou..
Is there some small caps in the signal path than are known to fail and cause this?

[trickyricky]

Am pretty sure it was there before, replacing the B+ filter caps will not cause noise....especially in one channel. Even if you replace the rail caps, it would not cause noise on one channel. More than likely the issue may be on your crossover daughter board as zeropoint mentioned. Try cleaning out all the pots and switches with proper electrical contact cleaner (I use/prefer Deoxit). If you have a True RMS dmm, check for DC and AC voltage present (without RCA's).

[TeleThunder]

Amp is now working
It does have a green quadpot on the crossover board, I cleand and viggeled this back and fourth.. did also this with the small pots on main board. And the flat cable from crossover board to main board had some marks after an old repair, so I resoldered this cable and some other soldering points around the board.
Powered it up and there was no sound from either speaker now, connected it to a cd-player and it played music with no noise what so ever
Thank you both for all help and advice, helped me alot, THANKS