Stiff Main Dial

SYMPTOM: Help! I am shut down on operation of my MP until I can resolve the following issue. My main tuining dial has suddenly, and I do mean suddenly - like within a period of about 20 minutes of operation, become very! hard to tune. I do not have a Service Manual, but the Operators Manual shows how to adjust the stiffness of tuning action. I did this and it helped for only a short time and then the dial became very stiff once again.
Has anyone had this occur to them and what is the most likely cause. It looks as if I need to take the front panel completely apart from the rear facing pc board to get at the dial mechanism. I'm not sure how tuning is accomplished but I assume its some sort of LED and phototransistor reading pulses from the dial. Fred KG9X

SOLUTION: I had a similar problem. Here is what I did.I took the knob off the front and stood the radio on its back, had it well supported. I put a little sewing machine oil around the shaft and let the radio stay in the upright position overnight. The next day it was as good as new and still is. I don't have the manual here, but I am pretty sure it tells you how to get the knob off. Tom W1TO

SOLUTION: I decided to take another look at the task of repairing the very stiff main tuning dial last night. The original thought was to come in from the pc board side but removing all the knobs and taking off the front bezel is correct. I spent over an hour disassembling the front panel to get at the control. The exact same control is used for the 2nd VFO also, by the way. It turns out the control is some sort of magnetic unit not LED/photo Xistor. I took the control apart figuring what do I have to lose, the thing is useless as it is now, so if I break it ... oh well. The control came apart very easily with just a little preying on its back cover. The problem appears to have been grit on the shaft or in the lubricating grease during assembly of the unit. I cleaned, polished and relubed the shaft using some Teflon grease. The control then ran smooth. It then took about an hour to reassemble the front panel, but everything went fine, no extra parts or anything broken. I don't know what this says for Yaesu quality. No one has emailed me back on this issue so far, so I guess its just a rare occurrence. I really love the MP otherwise. I put the unit back into operation last night at about 0600Z with my first contact being IT9AZY on 160M CW. No trouble tuning him in as condx were great. My last contact was with ZL9CI on 80M CW at about 0900Z. I was just about ready to call it quits as the pile-up was large and I run only the MP barefoot, but one last try and there he was in the log. Fred KG9X

SOLUTION: 3 The adjustment spring may have backed out, but I can't imagine how. The main VFO knob has a rubber skirt, pull the rubber skirt off to gain access to the removal screw. Please note the procedure is detailed in your operators manual under tension adjustment. AC5YV