Atari 800XL Doesn't Boot some cartridges

[hueyjones70]

I have an 800XL that will not boot a Pac Man, a Pole Position, BASIC, Star Raiders, AtariWriter, ans a QIX cartridge. It will boot Wizard of War and a special Pac Man that is a cart with out a shell.  I plan to try it with several more carts but I thought this was a really unusual situation that deserved some exposure.

[Forrest]

Clean the computer cartridge port with compressed air. Clean the cartridge port with IPA.

Edited July 24 by Forrest

[TGB1718]

I think some 800 Carts will not work on an XL, did all these work before ?

[Rybags]

Fairly sure all those should work on an XL.

At the least when a cart is not compatible you usually get some sign of life then a crash or lockup.

I suspect it's probably a physical connection problem.

Some boards are thicker than others.  Some cart slots don't have adequate spring pressure on the fingers.

[hueyjones70]

It must be a bad connection somewhere on the PCB. Today I took arm full of carts to the work table and almost all of them worked. An hour later, back to almost none working. I replaced the cart connector and same thing. Sometimes a particular cart works, sometimes not. I am going to check circuits with a magnifying glass and if I can't find anything it will become a potential parts donor.