Ok, heres the deal. I have a few consoles that have some problems.......and am looking for any help on fixing these!
1)  Just bought a PSX that POWERS UP and goes through the opening screen, etc...........but does not recognize the game disks.
2) I have a DC that I just bought that was used, as well........but it doesnt seem to recognize the disks half the time.  It has to be restarted numerous times to get it to work.  I have tried using a disk cleaner, let it go for over a minute on the cleaning setting like 3 times.........could I have inadverantly made it worse?
3)  Have another DC I have had for some time......bought the above one to replace it.  This one starts up fine, but shorts out sometimes in title screen, sometimes while deep in a game, sometimes not at all.  It resets and sometimes restarts the disk, but sometimes just nothign comes up.  I do not believe it is a disk problem.
I have used a disk cleaner on all three.  The only one it seems to have helped is number 3 to an extent, POSSIBLY.  Also, after the TWO bad experiences with the Dreamcasts, is my assumption true that Dreamcasts were constructed LIKE CRAP?  I love the games.....but the quality of the unit seems pretty bad.  Any remedies for these problems would be great, thanks!