I'm trying to repair a very stubborn TDS-520 fails on testing the proc and acquisition boards. Major capacitor leakage inside the unit. After a thorough clean and recap the unit this fails on both boards. Further research showed a track under a resistor that was broken. I repaired the broken track but it still isn't working correctly.
I found out there's a debug port: J40 (board edge connector). Information in the internet about this debug port is fragmented and far from complete. I'm trying to get this sorted out to a complete solution.
speaks about connecting an Option 13 (serial/parallel comm board) to this debug port. Separate option 13 boards are hard to find and otherwise quite expensive. It basically is nothing more than a pcb with a MC68681 Dual UART, some logic and 2 d-sub connectors.
Is there any schematic around of the Option 13 board? Or any other circuit that interfaces between the scope and the serial port of a pc?
Thanks.
