commodore 64 pla fix repair black screen start up

2 good ways of testing if it a pla that broke is sitch it on and off rapidly about 5 tims if one color or stipy then it you pla the other way of testing it if your lucky to have a c64 cartridge plug it in and if it run fine then it the pla if not then take a look at the link below C64 BLANK SCREEN http://personalpages.tds.net/~rcarlse... togo 30 http://shop.ebay.co.uk/togo30/m.html?... If there none listed just ask him a question on an item that has ended pla chips have diffrent mod numbers so ceck what yours is for example mine was 906114-01 yours may be diffrent such as (906114-05) etc....