Gottlieb System 80 voltage issue

[pinnies4me]

Haven't had time to get into the "spirit" of things too much yet, but exploring the sound problem. The previous owner replaced the relevant bridge rectifier in the hope of curing the issue, but it persists. This is the bridge that takes 28v ac and is supposed to supply 24v DC. It's getting 30v ac at the input which I assume is within tolerance, but the output is 38.1v DC which I'm guessing might be the issue. However, this is with the sound board power supply unplugged because otherwise the fuse will blow, and therefore under no load. Not sure if that makes a difference.

Any thoughts?

[Homepin]

first thing to do with ANY SS Gotlieb is to address the grounding issues - above any other things.  Refer Clays guides

[pinnies4me]

first thing to do with ANY SS Gotlieb is to address the grounding issues - above any other things.  Refer Clays guides

Agreed, but wanted to identify how I could end up with the odd voltage before traveling too far into the other bits. I've run a couple of "quickie" additional grounds to cover the basics though.

[Strangeways]

To be expected until the Ground mods are completed. Floating grounds and voltages out of spec are common. I run a long wire from the Ground tab on the Transformer board all the way to the power supply. Documented in the SYS80 Rocky thread.

[dj10555]

Once the ground mods are done, you can make up a load to put on the 24vdc rail to check all if within spec before testing it with the sound card.