Pulled from working vintage Gould Biomation laboratory / logic analyzer instrumentation. Highly sought-after vintage TDK PCU-555 isolated sub-board modules. They are electrically interchangeable plug-and-play matches, all Revision 5 listed (if you need a Revision 7, please message me - at this listing I have 9 total = only two are Revision 7). Perfect for maintaining, restoring, or archiving critical vintage laboratory infrastructure. These are compact internal sub-module featuring factory-applied thick fiberglass backing/insulation plates to safeguard against high-voltage shorting. Approx. 0.75" x 1.5” in size. Due to age, cannot confirm it has been recently tested so selling as is. Photos confirm excellent physical condition. All structural corners and mounting holes are 100% intact on these main selection units.

**** Please note that the black marker dots and precise punctures visible on the tops of the metal capacitor casings are intentional factory quality-control marks and manufacturing potting/vent access points from TDK Japan, NOT user damage or component failure.

* All original components, including the Sanyo OS-CON capacitors, sit securely on the board with their factory-standard button-top domed profiles intact.