1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Asahi Pentax LX with 'Sticky Mirror Syndrome'

Discussion in 'Pentax Chat' started by PeteE, Jul 6, 2020.

  1. PeteE

    PeteE Well-Known Member

    I have two ASAHI PENTAX LX cameras, one bought 1987 the other was a Free Gift from Asahi Pentax ( LONG STORY ----) but BOTH have the Dreaded 'LX Sticky Mirror Syndrome' -- I had a look and there are very small mirror 'rests' , slightly different from the 1987 model to the later model --- can I put some rubbing alcohol on them or Lighter Fuel ( BUTANE' ? I got the 'Exposure Problems' solved by rotating the Exposure Compensation and ASA dials back and forth as you do on the ME Super to clean the contacts underneath so both agree with my Weston Master V now but its the blasted 'hesitation' before the mirror goes up driving me mad !
     
  2. steveandthedogs

    steveandthedogs Well-Known Member

    Any help?

    https://www.pentaxuser.com/forum/topic/lx-sticky-mirror-117

    S
     
  3. PeteRob

    PeteRob Well-Known Member

    You'll have trouble putting butane on it - the boiling point is -0.4 C for n-butane. Iso-propyl alcohol takes a little time to evaporate. I don't think it is sold as rubbing alcohol in the UK any more, the EU solvents directive seems to have removed a lot of useful stuff from the market place. I last found it for retail sale at Maplin (now deceased) as electrical contact cleaner. It is probably the smallest molecular weight liquid solvent you will find, if you can find it. Dunno what it will do to the camera.
     
  4. steveandthedogs

    steveandthedogs Well-Known Member

    https://www.mbfg.co.uk/isopropyl-alcohol-ipa.html

    S
     
  5. GeoffR

    GeoffR Well-Known Member

    Isopropyl is available from Amazon
     
  6. Pontoneer

    Pontoneer Well-Known Member

    Readily available from CPC , this is the smallest bottle , larger ones are available .

    https://cpc.farnell.com/ambersil/ip...st=IPA&searchref=searchlookahead&exaMfpn=true


    With my LX , I found that running it on continuous with the motor drive and no film in would clear the sticky mirror syndrome any time I felt it was happening ; it usually comes from lack of use .

    Since my film bodies have lain unused for quite a while it will probably be that way again .
     
    Done_rundleCams likes this.
  7. John King

    John King In the Stop Bath

    Did you manage to clear your problem with a sticky mirror? Isopropyl alcohol is readily available off the shelf at the likes of RS Supplies who are mainly a trade supplier of electrical spares, bits and pieces but do serve the public. A 1 Litre bottle costs about £9.50. I bought 3 bottles at the start of the pandemic to make my own hand sanitiser (75% alcohol 25% distilled water with a a dash of washing up liquid.) I put it in a garden type spray bottle and works perfectly. The content of alcohol must be over 65% to be effective.
     
  8. PeteE

    PeteE Well-Known Member

    NO -- not cleared - what happened worse though was the early 1987 model shutter has broken -- the blind went halfway across then stuck and I could pull it across with a finger nail but it zips back to the middle leaving a gap .
     
  9. steveandthedogs

    steveandthedogs Well-Known Member

    Time for Newton-Ellis or similar?

    S
     
  10. cliveva

    cliveva Well-Known Member

    Try acetone, avalible from chemists, it will give a “chemical clean” with out leaving a residual, though. Not convinced it will cure the problem.
     
  11. John King

    John King In the Stop Bath

    On the internals of a camera I would definitely not use acetone. It is far to aggressive and will dissolve plastic!!! Acetone is next door to cellulose thinners and that will cause all manner of damage.
     
  12. cliveva

    cliveva Well-Known Member

    Yes, if used without care, a tiny drop applied with a hypodermic syringe and rapid removal with a lint free swab should do no harm, but if not done well will result in more harm.
     
  13. John King

    John King In the Stop Bath

    Sorry still would not risk it. Isopropyl alcohol on the other hand does the same job and is quite benign in comparison (except to corona virus.)
     
  14. GeoffR

    GeoffR Well-Known Member

    Given that there are more corona virus infections on the internet than in the population would Isopropyl work there?
    Acetone fumes are damaging to plastics, so even a tiny drop applied with a hypodermic could do considerable damage elsewhere in the camera, such as the focusing screen, If you wish to use it in your camera fine but be aware that it may damage something you can't access.
     
  15. John King

    John King In the Stop Bath

    Funnily enough, the spray cans that contain a very quick evaporating liquid that leaves no trace and sold under the trade description of Brake and Clutch Cleaner is also just as good at removing crud of any description including any lubricant. It works on brake mechanisms so a camera is walk in the park. (It actually works very well on filters!) This also would apply to lighter fuel or isopropyl alcohol or whatever you care to introduce into your camera in a situation where you are virtually working blind, you will most probably do more damage than help.
     
  16. GeoffR

    GeoffR Well-Known Member

    I am unsure what Brake and Clutch cleaner uses as the active ingredient but Carb cleaner is Carbon-tetrachloride and I wouldn't let it near a camera.
     

Share This Page