Curious Pentax LX Meter Behavior

Finn Lyle · 12-13-2020, 02:21 PM

Hi all, I managed to pick up an LX recently for peanuts, as such there was little background with the camera. So far, the only real problem seems to be that the meter turns and stays on when the film is advanced, so a cocked shutter will drain the battery down in a few days. It seems that with an uncocked shutter, the meter will turn on when the shutter button or exposure compensation lock button are depressed and turn off after 30 seconds normally. So just another reason to cock just before shooting. I thought this was the extent of the issue, but it seems that unless the shutter button is depressed, the meter is vastly overexposing the shot. I was shooting in snow today for example and the meter was giving me times of 1/4-1 second at ƒ4 with Tri-x, which is ludicrous.
Is this something that could be potentially fixed without having to replacing the circuit board? Curiously enough the mirror bumpers have been replaced so it must have been serviced recently. Thanks!

stevebrot · 12-13-2020, 06:17 PM

Originally posted by Finn Lyle

Is this something that could be potentially fixed without having to replacing the circuit board? Curiously enough the mirror bumpers have been replaced so it must have been serviced recently. Thanks!

Do you have a copy of the manual?

Pentax Manuals | Manual Focus Bodies

What you describe does not sound right. The meter should turn on with a shutter half press and should remain on for 25s unless there has been other activity. The cocked vs. uncocked state should not make any difference, from what I can tell in the manual.

Steve

(...not an owner, but would like to be...)

**ramseybuckeye** · 12-13-2020, 06:26 PM

Originally posted by Finn Lyle

Hi all, I managed to pick up an LX recently for peanuts, as such there was little background with the camera. So far, the only real problem seems to be that the meter turns and stays on when the film is advanced, so a cocked shutter will drain the battery down in a few days. It seems that with an uncocked shutter, the meter will turn on when the shutter button or exposure compensation lock button are depressed and turn off after 30 seconds normally. So just another reason to cock just before shooting. I thought this was the extent of the issue, but it seems that unless the shutter button is depressed, the meter is vastly overexposing the shot. I was shooting in snow today for example and the meter was giving me times of 1/4-1 second at ƒ4 with Tri-x, which is ludicrous.
Is this something that could be potentially fixed without having to replacing the circuit board? Curiously enough the mirror bumpers have been replaced so it must have been serviced recently. Thanks!

Do you have the manual for the LX? It may answer your questions. I don't have the camera, but if it has a shutter lock that would possibly turn off the meter for storing.

Finn Lyle · 12-13-2020, 06:53 PM

The manual just describes how the meter should behave, which is shut off after 20-30 seconds. The advance lever should have nothing to do with it as noted by Steve. It appears that the shutter lock does not have an effect on the meter being on/off though.

Huss · 12-13-2020, 08:04 PM

Correct, the shutter lock just locks the shutter. It does not turn off the meter.
Your bigger problem seems that the meter gives completely bonkers readings.

I've recently used Zacks Camera Repairs with superb results on my Leica M5, so if he can work on that, he can work on anything! (most Leica techs refuse to touch an M5!)

shyrsio · 12-14-2020, 10:06 AM

It is normal that the electronic circuit starts degrading after some time. Do you have the first or the second version of the camera? check the two initial numbers of the serial.

Finn Lyle · 12-14-2020, 09:07 PM

I’ll look into Zach’s, if they’re willing to work on it and can fix the issues that would be great, thanks Huss. I suspect Eric won’t as he’s told me in the past that lx electronic issues are no longer part of his repertoire.
What’s the separation? First two are 52.

Huss · 12-14-2020, 10:45 PM

Originally posted by Finn Lyle

I’ll look into Zach’s, if they’re willing to work on it and can fix the issues that would be great, thanks Huss. I suspect Eric won’t as he’s told me in the past that lx electronic issues are no longer part of his repertoire.
What’s the separation? First two are 52.

From a google search:

"During its long production run, the Pentax LX was updated at least three times. The latest camera revision has three visible differences compared to the earliest: there are two white points missing on the front of the first shutter curtain; pressing the button that releases the viewfinder causes the light meter to turn on, and the shutter-lock switch features a new design. Several attempts to gather information about camera serial numbers and design variations have failed due to inconclusive data."

The principle useful change in the late version is the increase of ASA from 1600 to 3200."

I'm happy to read that as I had no idea about different versions, and from the description above I have a late model LX.

Finn Lyle · 12-15-2020, 07:16 PM

From that description I do as well, since it goes up to 3200. I contacted Zach, and he said he will not work on an LX. So it’s going off to Eric now. Who knows, maybe if he cant fix it, it'll find use it as a parts camera to save another LX from the scrap heap.

shyrsio · 12-16-2020, 01:56 AM

Originally posted by Finn Lyle

I’ll look into Zach’s, if they’re willing to work on it and can fix the issues that would be great, thanks Huss. I suspect Eric won’t as he’s told me in the past that lx electronic issues are no longer part of his repertoire.
What’s the separation? First two are 52.

With the first numbers 52 its the first production run of the LX, therefore its quite old. The failing electronics is quite a common problem in this version. the best you can do is find a spare LX and transplant the electronics, if that is even possible.

Huss · 12-16-2020, 06:39 PM

Originally posted by shyrsio

With the first numbers 52 its the first production run of the LX, therefore its quite old. .

His has the ASA going up to 3200. Apparently the first production run only went up to 1600?

**Derek** · 12-16-2020, 07:15 PM

My 5278xxx has the old style shutter lock, but still meters to 3200 ASA.

Finn Lyle · 12-17-2020, 09:08 PM

Old style shutter lock is the little fingernail-lever, similar to on the MX correct? If so that’s what I’ve got too. Is it feasible to switch out the electronics myself, or would it just be easier and more cost effective to look for another LX all together. I’m beginning to suspect there’s not as much charm in owning one of these machines as I had hoped 😁

**Derek** · 12-18-2020, 03:43 PM

Originally posted by Finn Lyle

Old style shutter lock is the little fingernail-lever, similar to on the MX correct? If so that’s what I’ve got too. Is it feasible to switch out the electronics myself, or would it just be easier and more cost effective to look for another LX all together. I’m beginning to suspect there’s not as much charm in owning one of these machines as I had hoped 😁

Yes, the older shutter lock is similar in shape to the MX one. The LX is noted as being a difficult camera for a tech to repair if they don't have access to Pentax parts. There are dust/moisture seals that are not present in other bodies, but need to be replaced if an LX is disassembled.
I'm sorry to hear about your troubles. Is it feasible to work with it the way it is? I have two LX's, but the flash operation quit in the older on. I'll just have to sell it for a lower price when the time comes. They're not getting any younger, I'm afraid.

12-13-2020, 02:21 PM	#1
Finn Lyle Junior Member Join Date: Jul 2020 Location: Wisconsin Posts: 33	Curious Pentax LX Meter Behavior Hi all, I managed to pick up an LX recently for peanuts, as such there was little background with the camera. So far, the only real problem seems to be that the meter turns and stays on when the film is advanced, so a cocked shutter will drain the battery down in a few days. It seems that with an uncocked shutter, the meter will turn on when the shutter button or exposure compensation lock button are depressed and turn off after 30 seconds normally. So just another reason to cock just before shooting. I thought this was the extent of the issue, but it seems that unless the shutter button is depressed, the meter is vastly overexposing the shot. I was shooting in snow today for example and the meter was giving me times of 1/4-1 second at ƒ4 with Tri-x, which is ludicrous. Is this something that could be potentially fixed without having to replacing the circuit board? Curiously enough the mirror bumpers have been replaced so it must have been serviced recently. Thanks!

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12-13-2020, 06:17 PM	#2
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Finn Lyle Is this something that could be potentially fixed without having to replacing the circuit board? Curiously enough the mirror bumpers have been replaced so it must have been serviced recently. Thanks! Do you have a copy of the manual? Pentax Manuals \| Manual Focus Bodies What you describe does not sound right. The meter should turn on with a shutter half press and should remain on for 25s unless there has been other activity. The cocked vs. uncocked state should not make any difference, from what I can tell in the manual. Steve (...not an owner, but would like to be...)

12-13-2020, 06:26 PM	#3
ramseybuckeye Site Supporter Join Date: Apr 2009 Location: Hampstead, NC Photos: Gallery Posts: 17,294	Originally posted by Finn Lyle Hi all, I managed to pick up an LX recently for peanuts, as such there was little background with the camera. So far, the only real problem seems to be that the meter turns and stays on when the film is advanced, so a cocked shutter will drain the battery down in a few days. It seems that with an uncocked shutter, the meter will turn on when the shutter button or exposure compensation lock button are depressed and turn off after 30 seconds normally. So just another reason to cock just before shooting. I thought this was the extent of the issue, but it seems that unless the shutter button is depressed, the meter is vastly overexposing the shot. I was shooting in snow today for example and the meter was giving me times of 1/4-1 second at ƒ4 with Tri-x, which is ludicrous. Is this something that could be potentially fixed without having to replacing the circuit board? Curiously enough the mirror bumpers have been replaced so it must have been serviced recently. Thanks! Do you have the manual for the LX? It may answer your questions. I don't have the camera, but if it has a shutter lock that would possibly turn off the meter for storing.

12-13-2020, 06:53 PM	#4
Finn Lyle Junior Member Join Date: Jul 2020 Location: Wisconsin Posts: 33 Original Poster	The manual just describes how the meter should behave, which is shut off after 20-30 seconds. The advance lever should have nothing to do with it as noted by Steve. It appears that the shutter lock does not have an effect on the meter being on/off though.

12-13-2020, 08:04 PM	#5
Huss Veteran Member Join Date: Apr 2020 Posts: 629	Correct, the shutter lock just locks the shutter. It does not turn off the meter. Your bigger problem seems that the meter gives completely bonkers readings. I've recently used Zacks Camera Repairs with superb results on my Leica M5, so if he can work on that, he can work on anything! (most Leica techs refuse to touch an M5!)

12-14-2020, 10:06 AM	#6
shyrsio Pentaxian Join Date: Apr 2016 Location: Tirana Posts: 780	It is normal that the electronic circuit starts degrading after some time. Do you have the first or the second version of the camera? check the two initial numbers of the serial.

12-14-2020, 09:07 PM	#7
Finn Lyle Junior Member Join Date: Jul 2020 Location: Wisconsin Posts: 33 Original Poster	I’ll look into Zach’s, if they’re willing to work on it and can fix the issues that would be great, thanks Huss. I suspect Eric won’t as he’s told me in the past that lx electronic issues are no longer part of his repertoire. What’s the separation? First two are 52.

12-14-2020, 10:45 PM	#8
Huss Veteran Member Join Date: Apr 2020 Posts: 629	Originally posted by Finn Lyle I’ll look into Zach’s, if they’re willing to work on it and can fix the issues that would be great, thanks Huss. I suspect Eric won’t as he’s told me in the past that lx electronic issues are no longer part of his repertoire. What’s the separation? First two are 52. From a google search: "During its long production run, the Pentax LX was updated at least three times. The latest camera revision has three visible differences compared to the earliest: there are two white points missing on the front of the first shutter curtain; pressing the button that releases the viewfinder causes the light meter to turn on, and the shutter-lock switch features a new design. Several attempts to gather information about camera serial numbers and design variations have failed due to inconclusive data." The principle useful change in the late version is the increase of ASA from 1600 to 3200." I'm happy to read that as I had no idea about different versions, and from the description above I have a late model LX.

12-15-2020, 07:16 PM	#9
Finn Lyle Junior Member Join Date: Jul 2020 Location: Wisconsin Posts: 33 Original Poster	From that description I do as well, since it goes up to 3200. I contacted Zach, and he said he will not work on an LX. So it’s going off to Eric now. Who knows, maybe if he cant fix it, it'll find use it as a parts camera to save another LX from the scrap heap.

12-16-2020, 01:56 AM	#10
shyrsio Pentaxian Join Date: Apr 2016 Location: Tirana Posts: 780	Originally posted by Finn Lyle I’ll look into Zach’s, if they’re willing to work on it and can fix the issues that would be great, thanks Huss. I suspect Eric won’t as he’s told me in the past that lx electronic issues are no longer part of his repertoire. What’s the separation? First two are 52. With the first numbers 52 its the first production run of the LX, therefore its quite old. The failing electronics is quite a common problem in this version. the best you can do is find a spare LX and transplant the electronics, if that is even possible.

12-16-2020, 06:39 PM	#11
Huss Veteran Member Join Date: Apr 2020 Posts: 629	Originally posted by shyrsio With the first numbers 52 its the first production run of the LX, therefore its quite old. . His has the ASA going up to 3200. Apparently the first production run only went up to 1600?

12-16-2020, 07:15 PM	#12
Derek Site Supporter Join Date: Jun 2008 Location: Terrace, BC, Canada Photos: Albums Posts: 122	My 5278xxx has the old style shutter lock, but still meters to 3200 ASA.

12-17-2020, 09:08 PM	#13
Finn Lyle Junior Member Join Date: Jul 2020 Location: Wisconsin Posts: 33 Original Poster	Old style shutter lock is the little fingernail-lever, similar to on the MX correct? If so that’s what I’ve got too. Is it feasible to switch out the electronics myself, or would it just be easier and more cost effective to look for another LX all together. I’m beginning to suspect there’s not as much charm in owning one of these machines as I had hoped 😁

12-18-2020, 03:43 PM	#14
Derek Site Supporter Join Date: Jun 2008 Location: Terrace, BC, Canada Photos: Albums Posts: 122	Originally posted by Finn Lyle Old style shutter lock is the little fingernail-lever, similar to on the MX correct? If so that’s what I’ve got too. Is it feasible to switch out the electronics myself, or would it just be easier and more cost effective to look for another LX all together. I’m beginning to suspect there’s not as much charm in owning one of these machines as I had hoped 😁 Yes, the older shutter lock is similar in shape to the MX one. The LX is noted as being a difficult camera for a tech to repair if they don't have access to Pentax parts. There are dust/moisture seals that are not present in other bodies, but need to be replaced if an LX is disassembled. I'm sorry to hear about your troubles. Is it feasible to work with it the way it is? I have two LX's, but the flash operation quit in the older on. I'll just have to sell it for a lower price when the time comes. They're not getting any younger, I'm afraid.