I always store my unit with the batteries out, I pulled it out to mess with a new LAM and my goggles would not turn on with brand new lithium batteries.

It doesn't make any power up whine at all when I turn the switch, I removed the tube and the connections looked good, tightened everything back down, still no dice.

I was looking at my battery cap and noticed there is no spring under the brass/copper connection on the cap, is there supposed to be a part down there I'm missing?

What would you gentlemen suggest I do in order to diagnose the issue?

99% sure there's no spring under the contacts in the cap on mine either.

Mine has the brass connection

Try cleaning out the battery compartment with a mild vinegar solution and lightly scrub all the contacts. Then clean off the vinegar with distilled water.  Use a hair dryer to put some heat to dry it out thoroughly. Use a pencil eraser to scrub the contacts on the tube itself. Sometimes the brass tab that makes contact the battery can compress or break off entirely too. To see if the tab is compressed too far, install the batteries and screw on the cap and give the 7 a shake back and forth. If it is too loose then you'll hear the batteries move. If that is the case, then gently pull up on the tab until you get good contact with the batteries. Be careful, it can snap off. If the tab breaks off, you can just buy a new cap off Ebay or other site for around $25.

Thank you for the kind words. I'm very very far from an expert, but I'll give you my thoughts. I would try store bought today name brand batteries and see if it helps. Other things to look for besides what WJOutlaw mentioned is to be sure the objective housing is secure and also check the pin to tube contacts for corrosion. You could test the tube in a dark room by applying 3.0vdc to the tube's battery pads and see if it lights up.

Thank you, gentlemen!



How should I apply vinegar in the batt compartment? I can vaguely remember my dad doing this for flashlights when I was younger, but obviously a bit more apprehension involved with nods. Qtips/cleaning patches?



Have been thinking about testing the tube. But I assumed a tube issue would give me the "whine" of being turned on, while giving me no image. Am I incorrect in that assumption? (I.e. is it the tube that whines?)

Use vinegar and long Qtips to clean the battery compartment if you see signs of battery acid leakage. If the leakage was bad it's possible it could travel into the wiring and cleaning the terminals may not be sufficient to cure your problem. It's also a good idea to clean the pin to pad power connection to your tube.

A whine noise is a good indication your tube is getting power, but if you're not getting an image you may not be getting @3.0 VDC to your tube. Use a VOM to the power from the pins to tube pad connection point and see what is the voltage reading is. You can buy a simple volt ohm meter on Amazon for less than 10.00

Did you try a second battery?Edit; A pencil eraser works very well at cleaning contacts.

Turn on the built in IR illuminator to see if its getting power. You can just make it out with your eyes. My IPhone 11 camera can see it as well. That will tell you if the housing is getting power or not. Hopefully it is the housing and not the tube.

I had a PVS-7 on/off switch go bad years ago. Wilcox (repair guru, not the manufacturer) put a pvs14 switch in its place. It was $30-40 at the time vs $150 for a new housing. I eventually got a new housing as part of a batch of parts on eBay pretty cheap and switched it over. I had just enough parts to put together a spare beater housing after upgrading my -7.