Pentax K-1000 build-in lightmeter trouble

prof · 06-06-2018, 12:16 AM

Hi,

since a few weeks my Pentax K1000's build-in lightmeter doesn't work.
I changed the batteries, but still the needle doesn't move an inch.

Have you any suggestions on what might be the problem or how I can fix it (myself or through help)?
This pentax was my very first analogue camera and it has loads of nostalgic value to me.
Thank you very much in advance!!

Best regards,
Stef

**Alex645** · 06-06-2018, 01:48 AM

Originally posted by prof

Hi,

since a few weeks my Pentax K1000's build-in lightmeter doesn't work.
I changed the batteries, but still the needle doesn't move an inch.

Have you any suggestions on what might be the problem or how I can fix it (myself or through help)?

Welcome to the forum! The K1000 is a classic.

a) Are you aware that with the K1000, with your lens cap off, the battery will drain? To turn off the light meter, you must put the lens cap on the lens.
b) Are you certain the battery has sufficient voltage? I use a volt or multimeter. It is not uncommon to get a new button cell battery, only to find it isnʻt ʻfreshʻ. 1.5v cells, when new usually measure between 1.53-1.62 volts. If it measures 1.49 or less, it may not be enough to run a 40+ year old light meter.
c) The built-in battery check for the K1000: Turn the ASA to 100 and the shutter speed to B. The light meter needle should be pointing steadily upward.
d) Iʻm fairly certain that the battery is not required for correct shutter speeds which are governed mechanically. Therefore, you can use any number of light meter apps with your cell phone. Set the film ISO/ASA, and the app will give you various aperture and shutter speed combos.

Hereʻs a link to the ownerʻs manual if you donʻt already have one.
http://www.cameramanuals.org/pentax_pdf/pentax_k1000.pdf

stevebrot · 06-06-2018, 02:45 AM

Originally posted by prof

Have you any suggestions on what might be the problem or how I can fix it (myself or through help)?

Welcome to the Pentax Forums! A common mistake is inserting the battery upside down. The "+" side should face out. If the battery test (see comment above) fails with a known good battery, it may be that there is corrosion in the battery chamber or fault in the wiring.

Steve

MysteryOnion · 06-06-2018, 05:04 AM

Already good advice above...adding some other factors

Test:
Also set the camera down on a table edge facing a bright scene.
While looking through the eyepiece, test the ASA setting by lifting and spinning from one extreme to the other.
Also repeat for the shutter speeds.
There is a chance you may see the meter intermittently jump to life.
This is to rule out the problem is in the potentiometer brushes in the ASA board.

Also, could you share the overall condition of the K1000 body.

Dents ... any substantial deformation of the housing can short out the connections inside.

Fall damage... The meter has two snail coil springs that also are the electrical conductors for the meter and is easily damaged.

Age can be a factor. Humidity and heavy damp can effect the electrical contact...clean the contact with an eraser to be sure.

Which Era/Version...all metal or plastic shell... made in Japan or Hong Kong or China...?
The earliest versions may have foam that turned to a gooey mess and could cause problems. Although, foam tends to crumble from age.

ignath · 06-06-2018, 05:36 AM

i had problems with lightmeter in k-1000 too, which worked well with both SMC Pentax-A 1:1.7 50mm and Vivitar 1:2.8 MC 28mm in first 15 years [+10 more years before me], but later it recognized only the SMC lense. then the camera broke and i still haven't fixed any of both defects unfortunately.

Wild Mark · 06-06-2018, 05:47 AM

A common problem is the failure of the solder point between the battery harness and the wire. The battery harness connection is stainless steel making it really hard to resolder.

Wojciech · 06-06-2018, 11:47 AM - **1 Like**

Hi Stef, I had the same problem (K1000 of great sentimental value in which the light meter refused to work one day). In my case the problem was (as Wild Mark noted above) the failure of the solder point. Once you unscrew the bottom/base plate you can get easy access to the baterry harness and see if that is the problem indeed. Again, as Wild Mark wrote, the cable is hard to resolder as a standard lead/tin solder will not attach to stainless steel. I got a help from a friend of mine who had plenty experience in soldering and we had used a tin-silver solder (which apparently also does not wet stainless steel) for this with success. Another point of attention is that if you decide to trim the corroded end of the cable, be careful not to cut too much of it because it is already very short and reattachment of the harness can be impossible without the exchange of the whole cable (which would require further dismantling of the camera and I would not want to do it mysef).

A similar thread was posted a couple of years ago:
K1000 Light Meter - PentaxForums.com

Hope that helps,
Wojciech

06-06-2018, 12:16 AM	#1
prof New Member Join Date: Jun 2018 Posts: 1	Pentax K-1000 build-in lightmeter trouble Hi, since a few weeks my Pentax K1000's build-in lightmeter doesn't work. I changed the batteries, but still the needle doesn't move an inch. Have you any suggestions on what might be the problem or how I can fix it (myself or through help)? This pentax was my very first analogue camera and it has loads of nostalgic value to me. Thank you very much in advance!! Best regards, Stef

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06-06-2018, 01:48 AM	#2
Alex645 Site Supporter Join Date: May 2015 Location: Kaneohe, HI Photos: Albums Posts: 3,526	Originally posted by prof Hi, since a few weeks my Pentax K1000's build-in lightmeter doesn't work. I changed the batteries, but still the needle doesn't move an inch. Have you any suggestions on what might be the problem or how I can fix it (myself or through help)? Welcome to the forum! The K1000 is a classic. a) Are you aware that with the K1000, with your lens cap off, the battery will drain? To turn off the light meter, you must put the lens cap on the lens. b) Are you certain the battery has sufficient voltage? I use a volt or multimeter. It is not uncommon to get a new button cell battery, only to find it isnʻt ʻfreshʻ. 1.5v cells, when new usually measure between 1.53-1.62 volts. If it measures 1.49 or less, it may not be enough to run a 40+ year old light meter. c) The built-in battery check for the K1000: Turn the ASA to 100 and the shutter speed to B. The light meter needle should be pointing steadily upward. d) Iʻm fairly certain that the battery is not required for correct shutter speeds which are governed mechanically. Therefore, you can use any number of light meter apps with your cell phone. Set the film ISO/ASA, and the app will give you various aperture and shutter speed combos. Hereʻs a link to the ownerʻs manual if you donʻt already have one. http://www.cameramanuals.org/pentax_pdf/pentax_k1000.pdf

06-06-2018, 02:45 AM	#3
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by prof Have you any suggestions on what might be the problem or how I can fix it (myself or through help)? Welcome to the Pentax Forums! A common mistake is inserting the battery upside down. The "+" side should face out. If the battery test (see comment above) fails with a known good battery, it may be that there is corrosion in the battery chamber or fault in the wiring. Steve

06-06-2018, 05:04 AM	#4
MysteryOnion Giveaway winner! Join Date: Dec 2007 Location: beantown Photos: Albums Posts: 944	Already good advice above...adding some other factors Test: Also set the camera down on a table edge facing a bright scene. While looking through the eyepiece, test the ASA setting by lifting and spinning from one extreme to the other. Also repeat for the shutter speeds. There is a chance you may see the meter intermittently jump to life. This is to rule out the problem is in the potentiometer brushes in the ASA board. Also, could you share the overall condition of the K1000 body. Dents ... any substantial deformation of the housing can short out the connections inside. Fall damage... The meter has two snail coil springs that also are the electrical conductors for the meter and is easily damaged. Age can be a factor. Humidity and heavy damp can effect the electrical contact...clean the contact with an eraser to be sure. Which Era/Version...all metal or plastic shell... made in Japan or Hong Kong or China...? The earliest versions may have foam that turned to a gooey mess and could cause problems. Although, foam tends to crumble from age.

06-06-2018, 05:36 AM	#5
ignath Pentaxian Join Date: May 2018 Location: Riga Posts: 1,759	i had problems with lightmeter in k-1000 too, which worked well with both SMC Pentax-A 1:1.7 50mm and Vivitar 1:2.8 MC 28mm in first 15 years [+10 more years before me], but later it recognized only the SMC lense. then the camera broke and i still haven't fixed any of both defects unfortunately.

06-06-2018, 05:47 AM	#6
Wild Mark Veteran Member Join Date: Jun 2013 Location: Newcastle Photos: Gallery \| Albums Posts: 1,954	A common problem is the failure of the solder point between the battery harness and the wire. The battery harness connection is stainless steel making it really hard to resolder.

06-06-2018, 11:47 AM - 1 Like	#7
Wojciech Junior Member Join Date: Jun 2018 Photos: Gallery Posts: 36	Hi Stef, I had the same problem (K1000 of great sentimental value in which the light meter refused to work one day). In my case the problem was (as Wild Mark noted above) the failure of the solder point. Once you unscrew the bottom/base plate you can get easy access to the baterry harness and see if that is the problem indeed. Again, as Wild Mark wrote, the cable is hard to resolder as a standard lead/tin solder will not attach to stainless steel. I got a help from a friend of mine who had plenty experience in soldering and we had used a tin-silver solder (which apparently also does not wet stainless steel) for this with success. Another point of attention is that if you decide to trim the corroded end of the cable, be careful not to cut too much of it because it is already very short and reattachment of the harness can be impossible without the exchange of the whole cable (which would require further dismantling of the camera and I would not want to do it mysef). A similar thread was posted a couple of years ago: K1000 Light Meter - PentaxForums.com Hope that helps, Wojciech