what's this on digital back, and how to clean it

[EinstStein]

I have these from my digital back. See the edge of the image. It seems some fungus between the glass and CCD.
Exactly what are these? How and who can clean it? Please recommend a reliable repairer. 

[Paul2660]

It looks like fungus for sure.

It's going to need to go back to the company the manufactured the back to have the cover glass removed. Then the fungus can be removed.

What brand is the back?  Where are you located?

Paul

[EinstStein]

it is hasselblad CF39. I am in San Jose, California, USA.

[Paul2660]

I would find a local Hasselblad dealer, and have it sent back to the factory.  They may want to just replace that outer cover and clean the sensor.
Fungus, (many don't know this) is a pain as you have to kill it.  You can't just wipe it out.  They have to sterilize the back to really get out, or it will just grow back.  This is why the cost is so much for a lens that has it to be cleaned. 

This is having it done correctly.  I am sure someone can wipe it off, but the root cause is moisture, and the back needs the full treatment. 

It's also safe to assume it will continue to grow unless treated.

Paul

[EinstStein]

Thanks a lot.

I just found and called the service and repair section on Hasselblad web site. They recommend send it to their N.j site for estimation and repair. The price quoted on the web is not bad, it is about 350 Euro, exclude VAT and S&H.

My digital back actually has another problem. The time and date will reset to year 2000 just after about one day. This is after I charged the back through FireWire for 24 hours. hasselblad manual says the capacitive battery for the time and date can last 3-7 days. I might as well repair it at the same time.

[Paul2660]

It may have an internal battery that needs to be replaced.  The older Phase One P45+ had a real issue with this after about 1 year.  There was a internal battery that kept the date current.  Mine went dead after 1 year.  It was under Value add warranty, however I did not want to send it in for that (had to be sent to Denmark at the time).  I waited for another issue and had it replaced about .5 a year later.  The new battery lasted until I traded in the P45+.

Paul

[jerome_m]

Fungus is actually fairly frequent on some old Hasselblad backs, the IR window was sensitive to it. Hasselblad will exchange the window and that will solve the problem. I had this done on an old H3D-31.