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Last Revised: 2021-11-11
Here are some instructions for replacing the primary electrolytic capacitor found in several Minolta film SLR bodies. Over time, electrolytic capacitors are prone to failure and these Minolta bodies start to show strange behaviour like not actuating the shutter all the time.
If you’re handy with a soldering iron then it’s actually relatively simple to replace the old cap with a new one and revive a capable camera that would otherwise end up in landfill. I came across a few examples of this operation in the far corners of the internet but those had small, low-quality photos and I wanted to provide something that’s hopefully more detailed and easier to follow.
This guide applies primarily to the X-500 (or X-570 as it was marketed in the USA) but should also apply to the X-300/X-370 models as well. All photos shown here are of the X-500/X-570 model.
The X-700 has, as I understand it, an additional capacitor at the top of the camera and the replacement of that isn’t covered here. Replacing just the bottom capacitor is sometimes enough to get the camera working again and sometimes not.
These types of capacitor contain a liquid electrolyte and, with the passage of time, this can leak or dry out, leaving the capacitor with a reduced charge capacity. As the capacitor weakens, sudden loads (such as the shutter firing) are increasingly drawn directly from the battery. This causes the voltage to drop or “sag” momentarily before returning to its previous level. Once the voltage sag becomes too high the camera will shut down during shutter firing, as the voltage is no longer sufficient to drive the other camera circuitry. Replacing the capacitor restores the buffer of charge required to drive the shutter and, in many cases, that’s all that’s required to get the camera working again.
The camera used in this guide was received in a working state but as the original capacitor was still in place I opted to replace it preemptively. Photos shown in the gallery below are with the new capacitor in place.
To determine if the capacitor is original, take a look at the voltage listed on the capacitor can. You may need to gently lift the capacitor up and out of the camera body by half a centimetre or so in order to see all of the text. If the voltage rating is 4V then it is likely to be original, as caps with this voltage are less widely available nowadays. Other possible signs to look for are differences in the solder joint (colour, shininess, quality) relative to other nearby joints, and whether the capacitor appears to be a tight fit in the space where it lives, again indicating that it might not be the originally-specified part.
An extensive toolkit isn’t needed for this job. As long as you have a half-decent soldering iron and the skills to wield it then you’ll just need a standard screwdriver to access the circuitry beneath the base plate.
The original capacitor from the X-500 and X-300 will be either a 200uF or 220uF, 4 volt, electrolytic cap and most likely of the reputable Nichicon brand. Suitable replacements are easy to get, although capacitors with a 6.3V rating are likely to be much more widely available – you can freely go to a higher voltage rating but be aware that the physical size of the cap often increases as you do so.
Note: Apparently, the X-500/X-300 service manual calls for a 150uF, 3.15v cap so if you have trouble finding a 200uF or 220uF that will fit, you may well be able to use a smaller 150uF instead. Thanks to Roland in the comments for the info.
I used a Nichicon USR0J221MDD 6.3V, 220uF cap, available at RS Electronics with part number 475-8719. I like RS because they don’t have a minimum order quantity, which makes small, one-off orders like this more reasonable, but this is not an affiliate link :-).
The capacitor I chose is from the SR series and is 6.3mm in diameter and 7mm in length. This provides a good fit with plenty of room to spare. Other caps with the same rating will work. You could get away with a longer cap but I wouldn’t use one with a diameter much above 7mm as it might be a tight fit near the base.
The usual disclaimer before you go ahead: it’s always possible that you could damage the camera (or yourself!) by attempting the repair. If you’re not comfortable with a soldering iron and basic electronics then you should consider sending the camera off to a repair shop instead (maybe point them to this article!).
First, make sure that any film and batteries have been removed from the camera. I like to be certain that I’m not going to cause any issues if I accidentally short out any contacts with the soldering iron or solder wick.
That’s all there is to it. Once the camera is reassembled with batteries installed, take a few test shots without film to see whether the proper shutter operation has been restored.
That’s interesting; I didn’t know that. I added a note to the article and took the chance to give it a tidy up at the same time. Thanks for the info.
3 Comments
Porting over a few comments from the old site…
Anffray:
"Hi all !
I have two Minolta : the X300s and the XG-M
Both had the same problem :
– The lever couldn’t be pushed more than about 30° and the shutter release button couldn’t be press to take a picture.
– The led inside the viewer could switch on and and the light measurement could be done by the cell until the shutter button is pushed and then nothing is enlighten in the viewer.
So everything indicated that it was the capacitor of the bottom that was burnt/too old and that the cameras were stuck because the shutter couldn’t be released.
Living in France, I ordered my capacitor on Conrad (took 5 working days to arrive and costs less than 0,50 € for each capacitors).
I decided to respect exactly the capacitance and also as much as possible the voltage of the components.
For the XG-M I ordered a 100µF/6.3V which is exactly the same as the original one.
For the X300s I ordered a 220µF/6.3V which is also exactly the same as the original one.
(Apparently if you take a higher voltage it is not a problem but the capacitor could be too large for the space in the camera).
The replacement worked for the X300s but not for the XG-M so there might be other capacitors to change in that camera. (So I might have a look further one day (as we say in French "Quand j’aurai pas la flemme" and replace the other capacitors mentionned by StallBerger here : https://www.flickr.com/groups/1061226@N23/discuss/72157640473237815/72157640909097953 ).
It was so satisfying when I pushed the shutter release button on the X300s and that I heard the camera doing its job and firing and then the lever could be pushed as it should be.
This repair is easier on the X300s as the copper path is larger but with patience everything is achievable even for beginners ! You can use a piece of tape/blutack to hold the capacitor while soldering.
Take care !
Also here is a list of contents I read prior to identifying the issue and buying components :
https://www.paulbeesley.com/posts/2017/12/minolta-capacitor-replacement (Thank you for your help)
https://www.678vintagecameras.ca/blog/what-was-up-with-minolta-and-capacitors
https://simonhawketts.co.uk/2016/05/04/minolta-xg-m-capacitor-replacement/
https://www.photrio.com/forum/threads/how-to-identify-a-dead-capacitor-on-a-minolta-x-300-370-500-570-600-700.149035/
https://www.flickr.com/groups/1061226@N23/discuss/72157640473237815/
https://www.youtube.com/watch?v=-0XjHPRLzhk
http://www.twid.de/x700/index.html#fixc
https://www.chassimages.com/forum/index.php?topic=66596.0 French."
Dustin:
"Hi Paul. Excellent instructional. I just got an X570 with what seems like a busted capacitor. I put on fresh zinc-air batteries and the led inside the viewfinder would be flashing. Knew about the capacitor issue with these cameras and came upon your post. I’m in the US so your recommendation for the capacitor would end up costing a bit more for me but I found this:
Nichicon 220uf 220ufd 6.3V Volt 105 Degree Hi Temp Radial Electrolytic Capacitor
https://www.ebay.com/itm/Nichicon-220uf-220ufd-6-3V-Volt-105-Degree-Hi-Temp-Radial-Electrolytic-Capacitor/173374802509?epid=2226973415&hash=item285df18a4d:m:mFwI8s0KjoJ9qcQRhjq2d8A
You think the specs would be good enough? It’s a bit long at 11mm so I wanted to ask if you think this would work. Thank you!"
Dave:
"THANK YOU ever so much for posting this clear tutorial! This was just the ticket in bringing my mom’s old Minolta X-570 back to life. Much appreciated."
Danny:
"Gel-Flux is needed if re-using the old solder and/or if one-handed soldering."
Andrés Luna:
"Thank you very much for taking the time to write this down. I’ll try to do it myself right now."
Hi Paul!
I’ve noticed that in X-500/X-300 service manual the mentioned capacitor is 150uF 3.15v, not 200uF or 220uF, 4 volt.