I have several HP 6114 power supplies and I’ve had to repair them. The electrolytic capacitors dry up and need to be replaced or a good capacitor added to them. But the cheap plastic case of the 611x power supplies will shatter into many small pieces if you try to open them up. The front and back rings break very easily, and the case itself easily breaks, too. If the rings break but the case is intact, you can use tape to hold it together. The pots get noisy and difficult to set at a given value. It’s nearly impossible to find replacements. The neon light on the front can be replaced by a LED, diode and resistor. Or else use a LED and resistor on the output.
If there are any other bad parts, the schematic is available. But the parts can be unique to HP. Some are very specialized, like the potted circuits. Others can be replaced with a standard part, but it may have to be specially selected for proper performance.
Nowadays you can buy a new analog power supply made in Asia for fifty dollars US plus shipping. And it can handle more current than the old HPs.