yellow area on print

I seem to get a warm yellow tint on a print when I go beyond a six

times enlargement.This becomes a real problem at 11x14.I had it

fixed about 6 years ago and when I picked it up the repair person

was not there and could not tell me what was done.The problem

started again about one year after the repair.The enlarger is a

Saunders LPL670 dichroic.The yellow tint is about a two inch area

and becomes a problem in light areas like skin or sky.Dark areas

seem all right as you can not see it but I am afraid to make larger

prints as this ruins the print.

There is a light leak or something is out of alignment inside the enlarger head such as the bulb, dichroic filters, or light mixing box.

 

A third possibility is a reflection from a wall or enlarger column hitting the print.

 

Try printing without a safelight to verify that is not the problem.

 

Not using a stop bath after the developer will cause staining after making several prints using just plain water between developer and blix.

It sounds to me like you have some blue discoloration striking the paper. Can you take a look up there and see? Maybe just replacing the lamp would do it. Check the lamp for discoloration.