IC4 1/0 Board burnt pad off pin 4.

Hello there, I have had the misfortune of burning the pad off pin 4 of IC4 on the I/O board. I've socketed it and i had to desolder/resolder it.. unfortunately its gone. So i need to relink it to the proper point with a jumper. with all the rosin mess i can't see the trace lines on the pcb where they meet the IC and I can't find info on the IC in the original tr808 service manual as the yocto i/o is for the most part its own thing and . If anyone has that info or insight it would be much appreciated.

Thanks.

G

Hi,

you can download PDF schematics here https://www.e-licktronic.com/en/attachm ... achment=46 or download Eagle files https://www.e-licktronic.com/en/attachm ... achment=39 and trace the lines.

Thanks for the reply,

I've got the schematics and the Main board PCB layout, I've been over them lots, IC4 (74HC595) of the sequencer section is there, but i can't find IC4 (6N138) of the I/0 board anywhere in the schematic. I must be missing something?

G

Page 3 in the Yocto_IO_board.pdf..on the bottom by the midi in socket

Thank you, got it.

Seems like pin 1 and pin 4 (also indicated by the pinout in the 6n138 data sheet ) are not linked so i'm fine for that IC.

Now for more troubleshooting fun. I'll post my other issues R151 burns, wacky sequencer/ trigger woes in another post shortly.

Thanks again.

G