Try programming the radios without an eliminator code and see if they work together then. If so, there is something wrong with the eliminator code portion of the radio. Also, check your batteries, switch batteries between the units and see if the problem moves to the other unit. It takes more energy to transmit than receive, so a bad or very weak battery could exhibit a similar problem. The radio icon will illuminate whenever a radio is transmitting or receiving. When the radio is in standby mode, the icon should not be shown. Your radio with the icon on all the time may be stuck in transmit. Check your PTT button to see if it is slightly stuck or depressed. Here's a link to the user guide http://www.motorola.com/web/Business/Products/Two-Way%20Radios%20-%20Unlicensed/_Documents/XTR446/Static%20Files/XTR%20Manual%20EU.pdf?localeId=103
Downloading the manual will now make the batteries charge?
Use scanning to monitor channels for transmissions or to find someone
in your group who has accidentally changed channels.
1. Short press MENU until the "Z" appears. The current setting
On/Off will flash.
2. Press either + or – to turn On or Off.
3. Press the PTT to confirm or MENU to continue set up.
Here is a link to the manual http://www.motorola.com/mdirect/manuals/FV200_userguide.pdf
I could not find your model on the internet. Sylvania was never a walkie talkie manufacturer, so they were made by someone else. The ones I found on eBay had an off/on switch tied to the up down keys. Try pressing and HOLD for about 3 seconds the left side bottom button, then release. If that did not power it on, try the other buttons but be certain to HOLD for about 3 seconds since the button is dual purpose.
This is more for "mshtexas" than the OP but I'm sure there may be others out there wondering the same thing. The power cord that comes with this unit has a 9.0v output at 200mA with the center pin being positive
This one should be a very close match. The T4508 is a foreign version of the T4500.