Panasonic CRT Monitors

I got a pair of 6 or 8" Panasonic CRT security camera monitors from the ReStore that were just going to get scrapped. They are models BT-S702N and S700N. Both have good CRT's but will not pass a signal on any input. I tried passing a signal with my cable box with my F to BNC adapter but neither one will show a signal. I know my wire and adapter are good as I used the adapter on my scanner when I had an outdoor antenna. So my questions are: Is there something that may of failed inside that could be easily replaced?  Are these easily serviceable? Are they worth anything in their current condition, that I may be able to sell like on eBay?  I'd like to get at least the 5702 working since it has the option to operate on 12VDC and has audio connections. I'd get a Digital to analog converter box and a BNC to RCA adapter and use it in a power outage.

Those are for a cctv cameras signal or an av signal. It shouldn't use a rf modulated signal. If your catv box has rca jacks those are the ones you would use with the monitor.

I thought I could use an F adapter because while they were on the shelf one had an F to BNC adapter on it. However when a guy bought them, he returned them because they wouldn't work, but he kept the adapter. So I will get an BNC to RCA adapter then try them again. This adapter here should work, correct? http://www.ebay.com/itm/BNC-Male-Plug-to-RCA-Female-Jack-Adapter-Connector-Coupler-/331158710396? Thanks.

That's the one I use. Just make sure it is a straight video signal, unmodulated. If you find cctv cameras where you are getting the other things, those give a suitable signal also.

It appears to be a straight adapter. I just went ahead and bought 5 for 2.95, of the same adapter from the seller. I have yet to come across any CCTV cameras. I've only seen a little cheap wired security camera. If I ever come across any CCTV cameras that are the right price I'd buy them since I could always use a camera.

I've bought a couple of nice Bosch cctv cameras on Ebay for $10 apiece.

Years ago I worked at a factory and we had some of these monitors not being used. We had a Megerle grinding machine that the CRT went out. It was loosing tons of money for them and the internal monitor was shot. I had installed security cameras so I figured the security cameras might work. I tried it and it did. They used it until we got the parts we needed.

I had no idea cameras were that cheap. I just may have to pick up 1 or 2 and then get large enough 12VDC power supplies and mounts for them. It appears I can get a Bosch model LTC 0455/21 for 17.75 shipped. It seems to be an overall decent camera for that price. As it would work for my purpose great.

Those cameras run from 24v AC transformers. Here is a good one for the purpose.

http://www.mcmelectronics.com/product/82-1530

Those cameras say either 24VAC or 12VDC. However I'm not going to get one for awhile. I did get my adapters today and both monitors work great. One has better color than the other but I can't complain for free. I am just curious though as to why I couldn't get a signal to pass from the output of one to the input of the other. As soon as I hook up the other RCA cable to connect them the one I have the cable box hooked into basically gets a scrambled picture and turns grey. Then the second one looks like it's trying to get a signal but can't.
The S-700N:
The S-702N: