Chris,
I agree with Sandy. If you don't know what you're doing, don't even take the back off that radio. There are high voltages present, even with the set unplugged. There are components known as electrolytic capacitors inside which can store enough voltage to produce a lethal electric shock, even if the equipment in which they are installed hasn't been used for awhile (these parts can hold electric charges for months or even years). The proper way to begin a repair job on a defective radio or TV set is to unplug the unit first, then discharge the electrolytic capacitors to ground, which relieves these components of their charges (if any). Then and only then is it safe to work under the chassis.
I offer these safety tips for the same reason Sandy wrote what he wrote in his reply to your post--I too don't want to see anything bad happen to you. In the year or so I have been an AK member, I have found everyone here to be very helpful when I have had problems with my own small collection of antique radios (I have two, both Zeniths, not to mention a bunch of vintage transistor radios and some ham radio gear) and I also enjoy just reading these posts, both in the TV/radio forums and the audio-related ones (the latter as well as the TV forums, BTW, are much, much better than what I've read in the AudioAsylum forum--of which I am not a member at this time, and don't intend to be). The more I read them, the more helpful tips and hints I get.
I've been working with electronics, mainly as a hobby, since I was eight years old (I am now 48). I am also a ham radio operator (my callsign appears after my name in my profile signature), so I've been around electronics quite a bit and know my way around tube-type equipment fairly well. (Solid state, however, is another matter; I leave servicing of my TV, stereo, VCR, and ham radio gear, all of which are solid state, to the pros. I wouldn't feel comfortable working on modern PC boards with narrow traces, surface-mount components, etc.)
I moved to an apartment about five years ago and left most of my tools back at my former home, which means I've had to rebuild my toolbox here; however, that project is almost complete except for a couple things I have to get yet, such as a digital voltmeter and a soldering iron. I am hoping to do that very soon, as quite frankly I miss working on old gear, as I did in the basement of my former home in a Cleveland suburb (I now live in a small town just about ten miles east of the last true suburb of the city). I was able to get my ham radio installation going after a fashion (still have to work on that a bit, but the installation itself is in place in my bedroom and seems to be working), but I still would like to be able to return to electronic servicing, even if it is only on my own equipment.
I also agree with the person (Nick the 'Nole, IIRC--if I remember correctly) who recommended that you watch your spelling, punctuation, etc. when you post messages here, or in any other Internet message forum for that matter. It's not that difficult; as the other poster said, it makes it easier to read (and looks better in print).
I would also recommend, as did Sandy, that you at least study a radio repair manual before delving into your radio. Bear in mind, however, that just reading a manual won't make you an expert. If you feel the least bit uncomfortable working under the chassis of your set, please, let someone who knows what they are doing look at it and make repairs as may be necessary (I'd have that old line cord replaced, for starters; it's a shock and fire hazard).
As Nick also mentioned, any radio that's found in the trash can and should be suspected of having problems (especially if it's 30 or more years old), although many times people will discard perfectly good radios, TV sets, and the like just because they purchased a new one, because the cabinet doesn't match their living/family room/den decor, etc. (Some perfectly good TVs and radios, believe it or not, get pitched just because of bad tubes or blown fuses! I've seen this more times than I can count. Go figure.
) However, with old gear such as your "Medco" radio, I would go very slowly. Replace or have replaced the power cord, as it is no good in its present condition (see my note in the preceding paragraph), as a start; then, replace the filter capacitors (electrolytics), as these will deteriorate with age and become useless after a few decades of service. The controls will need a good cleaning, especially if the unit has been sitting unused for some time; I personally use Radio Shack's brand of tuner and control cleaner for this (works for me, to paraphrase the title character in the late-'80s TV series "Hunter"), although other AKers will tell you to use an aerosol cleaner known as DeOxit to remove corrosion, dirt, etc. from potentiometers (pots) and switches.
I agree with Nick as well that you should give us more information as to what your radio is or is not doing. Just saying "it won't turn on" doesn't give us (or
any repair person) much to go on.
If this radio's tubes are wired in what is known as a series filament string, one tube with an open filament will render the set inoperative. The solution, of course, is to replace the defective tube. If you have access to a tube tester, it will not only tell you the condition (cathode emission, et al.) of your set's tubes; it will also confirm that the tube filaments are intact. You can tell if the filament in a tube is good if the tube lights up after you set the tube tester for that particular tube (these settings are found in a tube chart, usually--almost always, in fact--supplied with the tester), and plug the tube into the proper socket on the tester.
I would check the tubes as well as replacing electrolytics, as a radio as old as yours could have weak, burned out, shorted or even broken tubes. If you see a white spot on the glass envelope of one or more tubes, the tube is defective as the envelope is cracked, allowing air to enter the tube (many of us AKers refer to a tube to which this has occurred as having "gone to air", meaning, of course, for whatever reason, air has gotten into the tube and rendered it useless).
The foregoing should be enough information to get you started working on your "Medco" antique radio. If you get stuck, remember, there are many helpful folks here, some actually in the business of electronic servicing, who will be glad to help you. The ladies and gentlemen here are a grand bunch of folks, as I have found in my short time as an AK member--and you will as well, the longer you are a member. I'm glad you're here. Welcome to AK. Hope to see more of your posts from now on.
And of course, please keep us posted how you're doing as far as restoring that radio goes. I know, from personal experience, what a kick it is to get these old sets working again, especially after they have been put in the trash or on a curb (this often happens with old TVs as well), stored in a garage, basement, attic, etc., and given up for dead, so to speak. Always remember, a radio, TV or other electronic device that has worked will work again (unless it is so far gone by virtue of having been allowed to rust, corrode, etc. that to repair it would be impractical), though it may take some work to get some sets with elusive problems, such as intermittents or other frustrating maladies, to play again as they did when they were new. Believe me, however, it is worth it when you turn on your repaired set for the first time and it works, maybe even better than it did when new.
Good luck and very kind regards,