Does anybody know the part number of IC2, a voltage regulator, used in the Excalibur Mirage chess computer?

The thing has a heat sink glued to the top,covering the part number, so I can't read it.

Thanks in advance.

Hi (unutterable name ),

there were two types of DC adapters by Mephisto. I suppose that yours is the older type. It is an IC 8414AB - TL497ACN. Exchanging it might be one way of repair, but it would be no good way, I think. You better take the chance and make a modern DC adapter of it.

The better (and I suppose cheaper and safer) way would be as described in my contribution to the thread https://www.schachcomputer.info/foru...er-4067-3.html, #22. For a Mirage you should take a "7806" instead of a "7805", for a Mirage needs 6 V instead of 5 V. And of course you do not need that switch shown in the picture, and I hope you understand pictures of electronic and you know soldering. That's all. Sorry for the description in German, however the pictures will tell you enough. Those "780x" are easy to get and cheap, so take the chance to give your Mirage a modern stabilized voltage. Forget those old electronics . Good luck!

regards
Walter

Sorry, I misstook the Mephisto Mirage with your Excalibur Mirage

Hi Walter,

Thanks for your reply my friend. The voltage regulator sits directly on the main board inside the computer. It's in a TO-220 package, but it's one of those 5-legged types (not 3 like the 780x fixed output series) so I suppose this is either an adjustable or multi-voltage output regulator. The problem is, it's dead. My cousin was playing it the other day and made such a bad/good move that he blew that regulator out, can you believe it?

There's a 74HC14 on that board so I need at least 5 Volts and the microcontroller probably runs on that too. The driver ICs for the stepper motors may need a higher voltage though.

So I really prefer to replace the part once I know the part number since I don't want to guess at what voltages go where...

Another option might be to try and pry that heat sink off while still retaining a readable part number underneath it. Talk about a long shot there...Maybe some kind of special glue dissolve would help.

If only I could find the schematics of the Excalibur Mirage, the mystery would be solved immediately.

John

This problem is fixed. After further examination, it turned out the defective regulator was not IC2 but IC3. This makes more sense, since IC2 can handle much more load then IC3, which is a small 100mA regulator.