Help with EHX Polychorus

[blustrat]

Hello, i hope this is the right section for this post, sorry if is not: i have a problem with an ehx polychorus, hope someone here can help me to solve it. The pedal works in the right way in double track and chorus modes but i have simple clean guitar sound when i switch to FLANGER or FILTER MATRIX modes. In these two modes if i rotate pots to max i can hear a light hiss that became modulated by the width and tune\delay controls, so i guess LFO is ok. Maybe a damaged chip?
Sorry for my english, hope someone can help me to fix this pedal on my own.
Thank you.

[theehman]

Check the solder joints on the selector switch.  They made need resoldered or the pads may have come loose from the board.

[blustrat]

Thank you Ron, i forgot to mention that i've checked the mode switch and all the contacts and solder joints looks ok, the weird thing is that i got clean signal from the pedal in that 2 modes 

[theehman]

you may have a bad delay IC.  Try swapping the SAD1024A chips around and see if those 2 modes start working.

[blustrat]

Great Idea!! I will try to swap these 2 chips this afternoon.. lunch time here now

[blustrat]

i've opened the pedal and there is no SAD1024 in it, there are one MN3009, one MN3008, and one SA571N, all are socketed so i can try to find a replacement for those chips and try to replace them.
Thank you again Ron!

[theehman]

i've opened the pedal and there is no SAD1024 in it, there are one MN3009, one MN3008, and one SA571N, all are socketed so i can try to find a replacement for those chips and try to replace them.
Thank you again Ron!

Is this a vintage or a reissue?  The reissue is stereo.

[blustrat]

Sorry, i forgot to mention is the reissue model, anyway seems like these chips are hard to find in stores here in my town 

[theehman]

Yeah, most store aren't going to carry those..

The MN3008 is used for the Double Track and Chorus modes so the MN3009 may be your problem.  You could try adjusting the bias trim for that IC (TRIM4).  It may start working again.
The MN3009 is pretty cheap but you may have to buy from China on ebay (2 for $9.99).

[blustrat]

Not for nothing you are the EH man! 
i am goin to try adjusting the trim.. i'l let you know. ThX again Ron!

[blustrat]

Trim test done.. unfortunately the modes still doesnt work, i've noticed that the sound degrade (sort of thunder rumble) when i turned the trim to a particular spot but still no effect. Thank you for sahring your knowledge Ron, i think the only way to go is to find a substitute for the MN3009, maybe an equivalent?
Greetings from Italy, Emilio.

[theehman]

I don't think there are any equivalents for the MN3009.

[Fender3D]

MN3007 and doubling the clock?