Hello good afternoon I would need if someone can help me with the repair of an old Philips radio which works perfectly, but I cannot turn the volume down to zero. The pot is 500K and when I measure it, it suits me, that's why I don't know where to go. The radio has UCH42 - UF41 - UBC41 - UL41 and UY41 Thank you

With the potentiometer placed at minimum volume, measure the resistance between the middle leg of the potentiometer and mass, you have to measure 0 ohm. If it measures more than 0 ohm, the audio signal is not completely derived to ground, and it will remain with volume remaining. In this case, measure the resistance between the leg of the potentiometer that is connected to ground and ground, it has to measure about 0 ohm (in fact the leg is connected to the secondary of the winding of the audio output transformer, and this in turn , is connected to ground). If it measures almost 0 ohm, then measure the resistance between the middle leg of the potentiometer and mass, there it must have a resistance much greater than 0 ohm, and the fault is of the potentiometer. It would be necessary to disassemble it to see if it is a problem of track, dirt, false contact, or burned. If nothing can be done, the potentiometer must be changed. The problem is that the audio signal is not completely grounded. According to the comment above, the problem would be between the leg of the potentiometer that is connected to ground and ground.

Hi Nico: I got a 500K pot with a key and I changed it, from that I can lower the volume to zero, but I notice that it is a radio that has a lot of gain because I put the pot in half and it leaves you deaf. Thank you in advance for your help.