Plundering the Planet From the Comfort of Home
Join Date: Jan 2006
Location: Northern Virginia, USA
Sansui TU-717 Grounding Issue
Really beautiful tuner, this one. Anyway, I cleaned the grounding tab that rubs on the tuning capacitor rod with a non residue cleaner and it now fine tunes perfectly, I had problems getting it to lock onto a station. Works like new now, but when I plugged it back in I sensed a very slight tingling when touching the outer case. Unrelated to anything I did, I'm sure, it is just that I noticed it then. The plug is unpolarized and I swapped it to the correct orientation (with striped portion of cord into wide portion of outlet) and the tingling went away. So I now have a polarized cord to swap the original out which will prevent the plug from being inserted improperly. In looking at the schematic, it seems that R701 could play a part in this issue. Is there any kind of test I can do to confirm my suspicions? Is that resistor a simple 3.3M ohm 1/2 watt or is there a special type of resistor for this application? Seems unsafe to have provided the unit with an unpolarized plug...