A complement to my previous question: I’m trying to indentify this electronic component in and old Pentax Spotmeter V light meter. It measures 178 ohm, but I’m not quite sure what it is, because it doesn’t really looks like a resistor. It is brownish of color, very tiny (a tenth of an inch or approx.2.5 mm) and has a white painted stripe on it, perhaps a color code. I was thinking maybe a thermistor, but I’m not sure.

Any ideas are welcome,

Thanks!

The yellow wire comes straight from the contact button and is going to the lamp, it is a sub-circuit. The lamp is there as an extra 'illuminator' to be able to read low light readings (in low light situations) on the scale. Nothing special really. But on the other hand, there is a similar component in red with a black marking, between the red wire going straight from the battery and the yellow wire followed by this brown component going to the lamp. Someone suggested a voltage divider, perhaps this is true: 2 resistors after each other. The red one reads 1.9 kOhm, the brown one 178 Ohm. the voltage of the device is 4.5 V (3x alkaline batteries). The voltage of the light bulb is unknown to me, but it withstands 4.5, I tested it. I don't know of this makes any sense?

But the light of the lamp is now so faint, and isn't working most of the time, that I'm wondering if this is the purpose?

This little PCB is the first one you encounter, btw, it is placed after the battery, so to speak.

⟐ Answer edited November 24, 2025 at 20:35 MST

I’m new to this forum and quite a newbie regarding electronics, so first of all hello to everybody.

I’m trying to fix a Pentax Spotmeter V light meter, an analog device that is at least 50 years old, and I’m looking for any information on schematics or parts that can help me out. Maybe there is someone trying to do the same as me or has the info I’m looking for?

Thanks!

All the Best,

Chris

⟐ Commented November 24, 2025 at 19:12 MST

⟐ Answered November 26, 2025 at 20:06 MST

Is there a way to easily remove the Back Cover without fully disassembling the camera?

⟐ Commented October 08, 2024 at 5:26 MST

⟐ Commented May 04, 2024 at 14:58 MST

I constructed a capacitor discharge tool out of 12AWG 600 V wires, a 20k Ohm 10W resistor, shrink tubing, and solder like the one constructed in this guide, so I could safely work on the camera, and after opening the it, I discharged the capacitor. All seemed fine and nothing looked or smelled fried.

After a little looking around, I discovered that the issue actually dealt with a small metal clip on the inside of the MF/AF switch that is attached to the front cover of the camera. The clip, which usually sits between the raised ends of a plastic bracket and moves the switch mechanism on the camera body up and down, was bent too far forward and was missing the bracket entirely. I bent it back toward the bracket a bit and voila, the coupler depressed when set to manual and reemerged when set to autofocus!

I reassembled the camera, turned it on, tested out the manual focus and it worked like a charm. However, when I went to test the autofocus, I was once again disappointed. When pressing the shutter down halfway in autofocus now, the camera's focus ring twitches between ∞ and 3ft repeatedly, never actually focusing or taking a photo. On top of that the flash no longer works in either mode. Did I adjust the clip too much and potentially short out the flash circuitry, even though I was doing everything as I thought I should? Please help me, iFixit community!

⟐ Commented October 09, 2016 at 21:46 MST

⟐ Commented March 15, 2026 at 13:08 MST

⟐ Answer edited May 11, 2024 at 11:55 MST

What can I do?

⟐ Answered October 01, 2019 at 5:41 MST

⟐ Commented April 21, 2025 at 0:17 MST

I recently purchased a Pentax LX from Japan and had already spent a considerable amount to fix the stuck mirror issue. However, upon receiving the camera, I discovered another problem: the light meter won't shut off. This is quite frustrating, as I have to remove the battery every time I'm not using the camera.

After some research, I found that this issue is quite common with the Pentax LX and that many repair technicians consider it unfixable due to the problem usually residing within the circuitry or main board.

Therefore, I came up with an idea: since the positive and negative terminals of the LX battery compartment are located within the camera body, and the battery door only serves to cover the battery, I was wondering if it would be possible to 3D print a battery door with a built-in switch. As shown in my rough sketch， pressing the button would push the battery up to contact the internal terminals, thus powering the camera. When not in use, pressing the button again would lower the battery, disconnecting it from the terminals.

My main challenges are that I lack experience in 3D modeling and cannot accurately measure the thread depth and diameter of the LX battery door. I believe the design of the switch's spring mechanism can be handled by professionals.

Therefore, I would greatly appreciate any suggestions or advice from the community. Has anyone attempted something similar or have any insights on how to proceed? Any help would be greatly appreciated.

Thank you in advance

⟐ Answer edited January 31, 2025 at 17:04 MST

⟐ Answer accepted March 07, 2023 at 13:32 MST

⟐ Answered November 09, 2018 at 11:15 MST

⟐ Answered June 17, 2016 at 13:39 MST

I have a Pentax Optio S5i compact camera and I’m trying to figure out if it can be repaired.

Symptoms:

• When I press the power button, it starts to turn on
• I hear the normal startup sound, but then it makes a beep-beep error sound
• The lens does not come out
• The LCD screen stays black
• The camera does not fully power on

The battery is charged, and there was no drop or water damage.

Does anyone know what usually causes this problem?

Is this something that can be repaired, or is it a common failure on this model?

Any advice would be appreciated. Thanks!

⟐ Commented October 18, 2025 at 2:08 MST

⟐ Commented March 19, 2023 at 11:23 MST

A month ago, my Pentax 6x7 TTL meter is dead. So I have done some research and try to fix it. I do not want to bother you with the long story, so I will just make it short and talk about what I have learn/find.

The meter has no response, it always stay at "+", which is where it stay when the meter power off. I suspect some of the contact might go bad, which may need some cleaning or re-soldering.

So, I have check the power and the shutter speed + aperture with a Multimeter, they all seem fine. So I go through the repair manual (which you can found it on google, free. I am not sure if I have the right the repost it, so I will not put the whole file here, sorry .)

The repair manual say that there should be 90mV go though the ammeter needle, when the needle go to the zero position. So I check the voltage of the ammeter(the needle)(blue arrow in the picture) , and find it max go to 17~19 mV. That why the needle always stay at "+" position, because there is not enough voltage for it. The good news, there is power get to PCB.

Here comes the interesting part.

Then I suspect this might be calibrate by the VR on the PCB. I know they had been calibrated by the factory, but at least I want to push up the voltage and see want we get. So when I turn VR6, there is a 50% chance the meter will back to life and the needle voltage will go to around 90mV, depend on the shutter and aperture setting . Now, if turn the VR6 it work for what is should be. (with power ON)

However, if I power off the TTL meter and on, the meter is dead again, and the needle voltage will back to 17~19 mV. This is repeatable with turning VR6 randomly.

There are something I also tried.

VR5 is close(see in the circuit map) to the ammeter(the needle), so I try to put it at the lowest resistance, and the needle voltage will go up to about 60 mV max, but still won’t push the needle. I also solder it off for check, it has a "22k" mark at the back, it should be response for it max resistance 22k Ohm. And the lowest resistance it can go is 3k Ohm.

Now If I do the VR6 trick, the measured voltage can add up, but it will go way too hight for the needle.

I think there is something wrong with the IC or related parts (the red square in the pic.). And according to the circuit map there is a transformer(?) which link the shutter and aperture resister to the IC , and there are some capacitors, not quite sure what they do. (sadly the repair manual do not state any spec. for the parts.)

I have borrow another pentax6x7 body from a friend for test, I am sure it is not the camera body problem.

Hope anybody might have some idea for this situation. I love the Pentax 6x7 and hope it can work again.

Thank you for reading this question. Good luck, stay heathy and stay happy.

⟐ Commented June 09, 2021 at 20:10 MST