Originally posted by sawitar ... One difference I have notices is that magnet used in DVD drive solenoid is slightly (1mm) higher than the one in the camera but all external/important dimensions were the same.
You have not used the proper "made in Japan" white Solenoid, but a DVD drive solenoid which also has a slight off impedance.
This could couse damage in the future.
Originally posted by sawitar ..... Put new solenoid in its place and solder the wires to it. I have put both covers temporarily back on and tested camera. It was not working any better. After some deliberation I flipped little magnet in solenoid upside down. And camera spring back to life. I have make about hundred test photos since. All well exposed
One has to measure polarity of the two coils, this is an induction magnet similar like very early loudspeakers where constructed, they had no permanent magnets but fieldcoil magnets. Those two coils induce an opposite magnetic field. Your DVD solenoid would have to be soldered with the wires exchanged so that polarity is correct.
Originally posted by sawitar Internal resistance (measured using cheap Chinese multi-meter) of both parts :
- Original green Pentax solenoid: 14 ohm
- DVD ripped solenoid: 26 ohm
Strange: every green solenoid I have measured had about 30 ohms!
I only used white solenoids with 30 ohms (29-31 ohms).
Originally posted by sawitar Btw. I do not recommend soldering wires midway as this is actually more difficult to do and involves way more solder and heat.
If one is a beginner in soldering
Originally posted by suraswami YAY!! fixed it. I learned how to Solder too
better not to make such silly statements!
If one presolderes the thin wires and then solderes them parallel (first pull a tiny piece of shrinking-tube over one side of each of the two wires) there is no excessive solder and heat. For those unexperienced maybe a saver way. The extra thickness of the two wires with the added shrinking-tubes does not interfere.
Originally posted by sawitar Soldering station available from German shop starting with 'L' won't do as it doesn't have right tip.
Nonsense:The two German producers are
Weller and
Ersa. Both have exchangeable tips.
The right tip is the tip one choses.
Originally posted by sawitar Soldering irons available in diy shop do not allow for temperature control and don't have right tip.
There are of course soldering irons with temperature control such as the Ersa PTC70, not that I would buy it, one can get a whole Ersa
soldering station for that price.
But the small 15W Ersa can use the finest tiny tips and will not be too hot:
https://www.amazon.com/ersa-Universal-Soldering-chisel-shaped/dp/B01KTVNAT2/...words=Ersa+15w
This is the one I use when I visit others:
amazon.com: Multitip 15W/910BD ERSA: Appliances?tag=pentaxforums-20&
and this is the best soldering station for me:
ersa RDS 80 electronically temperature-controlled soldering station, 80 W, 115 V - - amazon.com?tag=pentaxforums-20&
With all Ersa soldering irons, one can use the finest pencil-tip tips:
https://www.amazon.com/ersa-soldering-0832SDLF-lead-free-extended/dp/B00LW45...+soldering+tip
but I can solder the wires very well with the standard 2.2mm tip, but.... I know how to solder.
If one does not really have any real experience, recommendations like yours can and will mislead others!
One should only recommend things if one knows (by experience and not the nilly-willy content in one's head!)
Another critical recommendation of yours:
Originally posted by sawitar I have removed bottom and front cover from my camera and located faulty solenoid (as per instruction from first page. No need to remove top cover).
The top cover is not completly removed, because it still has some cables connected to the main electronics.
One lifts the top cover for easier access to solder the solenoid.