I've done a lot of searching but haven't found much regarding film Advance lever/trigger errors. Symptoms: lever will advance once or twice, with the firing sound being a dull "krk", not the bright "K-chung!". After one or two advances, the mechanism becomes jammed, and one cannot fire or Advance. Removal of lense showed that mirror was not flipping up during misfire. Removal of bottom plate showed that internal mechanisms were not pulling spring fully, which was not cocking the firing gear hammer arm(I wish I knew the nomenclature! See pic.)

Any clues? I read somewhere that the white firing gear may just need lubrication.

Would wd-40 be appropriate for internal SLR mechanisms?

Thanks in advance mechanism in question. Spring at top, driver touching hammer arm, white gear  in middle

  • 1
    I'd avoid the WD-40 as it is more of a solvent than lubricant. Sorry I don't know exactly what to recommend. I got a lot of mileage out of my SRT101, it was a good camera for me. – user7264855 May 20 '17 at 2:14
  • If you move the gear you are talking about, does the mirror move? The internals of my working SRT 101 look just like yours, except that some of the metal parts appear yellow on mine. – ToastHouse May 20 '17 at 4:57
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    WD-40 is a moisture dispersant and cleaner, not a lubricant. The "WD" literally stands for "Water Dispersant." When it is wet it will make things slide a bit easier, but when it dries out they will be less lubricated than before because it will have washed away most of what lubrication may have been present before spraying it with WD-40. For most internal camera applications that require lubricants use either a thick lithium based grease (gears, levers, etc.) or very small amounts of mineral/machine oil (pivot points, etc.). – Michael C May 21 '17 at 2:50
  • I found this years late whilst reviewing one of the answers - the popular, yet incorrect 'factoid' that WD40 is not a lubricant - wd40.com/myths-legends-fun-facts - though I still wouldn't use it on something like this. – Tetsujin Jul 21 '20 at 8:54

Use electronics cleaner on the mecahnism shown in your pic. You need to free up the gunk that is making it stick. The cleaner removes the gunk and it evaporates quickly. Only lubricate if you absolutely need to. WD-40 is an option, but be careful not to overspray.

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