New member first post..... I'm attempting to revive a 35 year old professional synthesizer. One problem I quickly identified was the 5VDC rail was sitting at 3.76. I isolated the PSU and tested.....same result. I replaced the regulator and electrolytics and tested. Perfect. Stayed right at 5vdc even under full rated load. Connecting the PSU to the electronics, still the drop, so isolated the offending board and first did an solid visual. All looked good. Next, I pulled all 25 of the bypass/decoupling caps. As they're cheap and easy to replace, it made more sense than pulling and testing them one by one. Now, I need to wait for a couple days for parts to arrive. Here's my question: To satisfy my impatience, would it be safe to momentarily connect the PSU to the problem board to see if I'm still seeing the drop? Thanks, everyone. Jim