Mod Chip Problems?

[Seven Kevin]

I have an older PSX and use a goldfinger with excellent results.
My friends machine has no parallel port so I suggested he use a mod chip. We made sure the mod chip matched the model number and ordered it.
I didn't see the installation but he said the directions were followed carefully (theres only four wires)
His son fired it up and games (even original) wouldn't play. He removed the mod chip and games still won't play.
Hoping someone might help us out in what might have went wrong and if anyway to correct it.
Could have the mod chip damaged his machine?
I have never (that I can remember) seen anyone posting about mod chips being faulty or not working so assume the success rate of installation is very high.
Appreciatte any information on this problem Thanks in advance.

[BLOODSUCKER]

TRY THIS
WHERE YOU SOLDER WIRE No 6 ON THE BOARD
PLACE A SMALL AMOUNT OF FLUX ON THE RESISTER
OR WHAT ITS CALLED AND THEN TOUTCH WITH
SOLDERING IRON WITH SMALL AMOUNT OF SOLDER ON IT / THIS SOMETIMES WORKS
THIS IS BECAUSE WHEN YOU SOLDER THE WIRE
ON THE FIRST TIME IT TAKES THE SOLDER AWAY
FROM THIS ESECIALY IF YOU HAVENT TINNED THE
WIRE FIRST
GOOD LUCK

BLOODSUCKER

[Seven Kevin]

Thanks I passed this on to my friend. Appreciate the help. Heard back that his solder job was questionable and that the gun may have touched an additional point. Not to mention the watts or heat may have been too high.
Seven Kevin