Just purchased an Atari Jaguar on eBay? Maybe If you were lucky enough even with the CD attachment? Many people buying second hand Jaguar units dont have the luxury of the instruction manual included so heres a few do's and donts followed by some common faults and how to remedy them.
THE GOLDEN RULE Jaguars wont power up unless a cartridge is in the machine, many people try to fire it up without a cartridge in the slot and wonder why it appears dead.
Atari Jaguar Power supply units are the same for both the base unit and the CD attachment - they are interchangeable If you are having a problem with either the base unit or the CD add on try swapping the PSU's over, it may be something as simple as a fuze has blown in one of the plugs
If you are using a standard RF lead it can be tricky to tune your TV as the signal seems to be very narrow - I would strongly recommend purchasing a Scart or Peritel cable as they are called in France, as long as your TV has a scart socket it will save all the fiddly tuning AND give you a much better picture quality. For the USA a composite cable or S Video cable is the next best thing. Expect to pay between £10-£15 for a Scart cable theyre not cheap but theyre certainly worth every penny.
Dead Jaguar game cartridges are VERY Rare some that appear dead are just in need of reseating in the slot a half a dozen times or so to polish the contacts. NEVER attempt to clean the contacts with abrasives, a little rubbing alcohol on a cotton bud is the recommended procedure that and good old patience and perseverance.
Contrary to what some dealers would have you believe most Jaguar cartridge games are pretty common, and always available somewhere on eBay usually still boxed mint. Unboxed carts without overlay, or manual cost substantially less and if all you want them for is to play them then go for these, the game manuals, overlays and box artwork are all available for free download at the Atari Age website should you want to upgrade your games storage later.
You should not remove a game cartridge from your Jaguar without first powering down the system although it is quite forgiving and on the occasions I have accidentally done it nothing nasty happened. BUT Atari must have made that rule for a reason so its best to respect it if you can.
The Jaguar CD unit can be a real beast to seat properly on the main Jaguar base unit, It requires real firm pressure till it clicks all the way down, It can suffer from the same dirty contacts problems as game cartridges after all it is using the same port, so if there is no connection at first - unseat then reseat it a half a dozen times. Try not to push on the lid, but at the back and on the sides.
The Jaguar CD unit can be tempremental to say the least and it has a couple of design flaws, the most noticeable one that completely stops the discs from spinning is the central hub gets pushed down on the drive spindle which has a braking effect, it can be carefully lifted back up the shaft by gentle lifting with the tips of two fingers placed at opposite sides of the hub, many units returned to Atari as faulty had this simple and easy to rectify problem.
The Disc and Question mark symbol - If you get this on your TV you at least know the CD unit is getting power and is connected to the Jaguar Base unit properly. Try a different Game disc if you have one, If you get the ? with all Jaguar Game discs then there is probably a problem mwith the CD unit - check now for the pushed down hub problem outlined above. If it is not that then you may have a Lazer read problem, this is not as terminal as it may sound, there are several very good free online troubleshooting guides for adjusting or even completely replacing the Lazer unit in these machines, links to these can be found at Atari Age or Jaguar Sector II websites - easilly found with a google search.
As a last thought - still getting a ? - are a sure its an atari jaguar game CD you have in there? If still yes then is it one of those unencrypted homebrew games that require an encryption bypass cart to enable them to load? The Jag CD Unit will display the Disc and ? if it cant find encryption on the disc.
If youre going to collect the rare unencrypted Homebrew stuff and some of the unencrypted demos/unfinished prototypes that were in the pipeline when Atari finally went bust, then you will need a bypass cart - Songbirds Protector SE game cart has this feature built into the cart and is probably the most cost effective way to go. Short of looking for a Jaguar development system which can be pretty expensive.
I hope this simple guide has been of help, please vote if you found it of use.