Gossen Luna Lux SBC, how to replace the battery connector???

[Tim Murphy]

Dear Board,

I have a Gossen Luna Lux SBC that was not working. I bought a replacement battery connector; twist spliced the wires together after cutting off the old connector and it works fine.

My problem is that there is little to no room in the battery compartment for any additional wire. It's a very tight fit with the existing factory wires and a 9V battery. I want to permanently replace the existing wires from inside the meter casing on out.

Does anyone know how to disassemble the meter case so I can connect the new battery connector directly? I am the type of handyman who prefers bigger hammers or blue tipped wrenches to handle stubborn problems. I'm hoping someone can help me from destroying something I want to fix.

Regards,

Tim Murphy

Harrisburg PA 🙂

 

[raydm6]

@Tim Murphy, I don't (I have a Luna-Pro SBC) but this thread and pictures on p.net might give you some clues.

https://www.photo.net/forums/topic/442634-gossen-luna-pro-sbc-repair-help/

Looks like the metal plate on the back comes off to expose the PCB assembly area (rather than opening the clam-shell). Perhaps you can unscrew the PCBA to access the soldered battery wires and replace/repair accordingly.

Fortunately the metal cover pops off the back easily on these, though it wasn't obvious to me initially (I thought the case was going to split on the side); and was about to give up when I noticed on Ilya's photo that the plastic case was still fully assembled.

 

[Tim Murphy]

@Tim Murphy, I don't (I have a Luna-Pro SBC) but this thread and pictures on p.net might give you some clues.

https://www.photo.net/forums/topic/442634-gossen-luna-pro-sbc-repair-help/

Looks like the metal plate on the back comes off to expose the PCB assembly area (rather than opening the clam-shell). Perhaps you can unscrew the PCBA to access the soldered battery wires and replace/repair accordingly.

Dear ray,

I got that far but I am reluctant to remove the circuit board to gain access to the battery connection terminals. I am afraid I'll do more harm than good doing further disassembly. I have an innate ability to make the simple extraordinarily complex.

I know the meter will work and since I bought a 2-pack of 9V terminal connectors I think I will try a simple soldered wire splice to the existing wires for now and cover them with a turn or two of electrical tape. If that works, I'll be good. If it doesn't, I'll dive deeper since I just received a nice Minolta IIIF meter from KEH so I have at least one "good" meter.

Regards,

Tim Murphy

Harrisburg PA 🙂

 

[oldhaven]

Look up ”solder seal” wire connectors. They are not much larger in diameter than the spliced wires and are easy to use with a heat gun to melt the solder. You may have to make a shield to deflect the hot air while using the heat gun with a small nozzle tip.

 

[Tim Murphy]

Look up ”solder seal” wire connectors. They are not much larger in diameter than the spliced wires and are easy to use with a heat gun to melt the solder. You may have to make a shield to deflect the hot air while using the heat gun with a small nozzle tip.

Dear oldhaven,

Thanks for the tip, I ordered a batch from Amazon and should get them tomorrow. I'll report back if I manage to get the repair done and close the battery compartment too. That's the biggest issue with the Luna-Lux SBC. Even fresh from the factory fitting a 9V battery along with the wires is tough. I'll probably have to ditch the foam battery pad to fit everything.

One thing I will say though is that the battery connectors I bought to re-wire the meter from Amazon are lightyears better than the factory Gossen connector. The factory connector has swiveling terminals that rotate under the vinyl cap that houses them like most old 9V battery devices did. I think the swivel broke rendering the meter INOP. The cheapies from Amazon have the terminals locked in a plastic shroud, there is zero chance of ripping a connection trying to remove or install a new battery.

Regards,

Tim Murphy

Harrisburg PA 😉