LC 475 - Need help with a lifted pad & repair(?)

FlicTheBunny

New Tinkerer
Dec 18, 2022
17
12
3
UK
Hi,

Due to a Rookie mistake I made during recapping my LC475 board, I pulled the +ve pad off the board at C35 (rear of the board by the RAM slot). There's no pad or trace left to bodge wire to on the top surface, the trace was only 2mm long and dives right into a via that I'm struggling to trace. I found a circuit schematic of the LC 475, and it lists C35 and C36 in tandom simply as "DRAM SIMM Bulk Bypass Caps" and they are tied between +5V and GND. It makes sense, they are at either end of the RAM SIMM slot. I assume that means they are providing some kind of suppression for the +5V going to the RAM to reduce noise.

The issue is, I don't know if I should just leave C35 off, or repair it, and if I repair it where would be the most effective place to tie the +ve side into the +5V rail.

LC475-booboo.jpg
 
Last edited:

vtgearhead

Tinkerer
May 1, 2023
87
33
18
Burlington, VT USA
If you can clean out that via (left side of cap) it should be a straightforward fix. Thread a short length of #30 wirewrap wire down through the via and tack it to one side of a replacement cap. Be sure to remove the remains of the old cap lead on the right pad!