Bicycle Mechanics - Dura Ace shifter not working!

So, much to my happiness and joy, I received my first cyclocross bike from a fella on ebay. Put it together and took it out for a ride & while trying to get comfortable with the right lever (shifting the rear derailleur) it just simply stopped. The levers still swing to the left, however upon inspection I noticed that the cable isn't being moved. I'm desperately trying to convince myself that this is something easily solved (maybe it just needs greased down?!), but I'm worried I'll have to shell out cash for a new one.

Anyone else have this problem before?

Is the cable threaded correctly? as in, was it inserted at the start of end of the shift cycle, it will go both ways, but only work when inserted at the correct one.

7800 http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Dura-Ace/ST7800/SI-6JA0A_En_v1_m56577569830610604.pdf

7900
http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Dura-Ace/SI_6RT0A_004/SI-6RT0A-004-ENG_v1_m56577569830702962.pdf

I had a similar problem with Ultegras except mine locked up. They were dead after about 1500 miles.

I went to downtubes and never looked back. If they are not threaded wrong the pawls may be stripped.

I had a similar problem with Ultegras except mine locked up. They were dead after about 1500 miles.

I went to downtubes and never looked back. If they are not threaded wrong the pawls may be stripped.

Yeah, you keep retrogrouching with control systems that don't make sense. Every single low to high end modern road bike is spec'ed with integrated shift and brake levers for a reason.

What cog is the chain on out back? If large/low or some intermediate gear, check cables and housing, cable end at the shifter for fraying. If it won't shift from the small/high cog, spray the bejeesus out of it with solvent or wd40. And cross your fingers

Bah, sorry to leave you all hanging - I'm terrible with keeping up on the internet. Anyway, oddly enough the what-ma-call-it (the piece inside the shifter that physically rotates the cable to produce tension) must have been gooked up for whatever reason. It's a rather old shifter that looks like it's seen some days (it's on a cyclocross bike purchased from ebay...risky, I know). I just squirted a fair amount of lubricant directly into the part in question & after toying with it for a few minutes it freed up & has been working ever since.

The first thing to check on failed STI levers is the cable. It can be broken up in the housing an not be obvious. Test by drawing it away from the down tube like a bow string and see if you suddenly pull down tons of slack indicating a break. If not try shifting the lever against that same tension.

If the cable seems OK, it's possible - especially on levers that haven't been used for a while - that dried, or hardened grease is keeping the small spring loaded parts from moving freely. Cross your fingers and say a prayer because this is the easiest and cheapest problem to fix.

Spray the mechanism with solvent ot super thin lube , like WD-40, LPS-1 or whatever you have to dissolve and flush dried lube. Rest it a while then work the lever and see if it comes back to life. Dry it as best you can, and oil with a light oil, and consider yourself lucky, because most actual mechanical failures are not repairable, and these levers aren't cheap.

Spray the mechanism with solvent ot super thin lube , like WD-40, LPS-1 or whatever you have to dissolve and flush dried lube. Rest it a while then work the lever and see if it comes back to life. Dry it as best you can, and oil with a light oil, and consider yourself lucky, because most actual mechanical failures are not repairable, and these levers aren't cheap.

This is how I fixed my Dura-Ace shift levers, WD40. They've worked trouble free for many years since.