Sony SLT A65 translucent mirror problem

[AntonioS]

Hello !

A friend gave me an old Sony SLT A65 that was locked in a suitcase for some years and guess what... It was pretty dirty.

The translucent mirror looks strange. I know it's a pellicle mirror, but something is really weird , at least to me who never saw this entity before.

It shows a rainbow pattern when lit, like a diffraction grid. And when I point the camera to a strong light source, let´s say streets lights or car lights, a huge halo and a diffuse pattern appears, almost like one of that photographic filters from the '70s.

I guess the mirror is damaged. Does enyone have any experience with this ?

I managed to remove the mirror and carefully rinse it with water and detergent solution , rinse again and dry, but the rainbow patter persists.

My question is basically about the translucent mirror behavior with strong highlights and if the rainbow pattern on its surface is normal.

 

Thanks!