So I must have the worst luck. My six year old (3 yrs with me) Apogee Alta U16M camera has developed a massive multiple column defect. I think the problem is actually due to one pixel going rogue. That pixel is now glowing inside the camera lighting up an entire area, and causing about 50 columns to be completely saturated in a BIAS exposure. This defect, sometimes called pixel luminescence is apparently very rare, but very fatal.
After the sudden appearance of the defect I went back thru my old calibration frames and lo and behold located a innocuous hot pixel complex at the same coordinates. What I mean by a complex: a bright/hot pixel directly surrounded by other warm pixels that make the entire thing look like a slightly out of focus star.
So after getting sticker shock from the cost of a new replacement camera I am looking at options. So my current options seem to be: bite the bullet and pay (offset by selling off other gear), mothball the observatory, partner with academic outfit or private individual or group.
Any other options and/or opinions welcome.
EB
Attachments:
Current bad bias frame
Previous good bias frame
Current bad dark frame
Crop of previous hot pixel complex from good dark frame
FITS file of above
Explanation of pixel luminescence
Example of pixel luminescence
That's very sad, Eric! My camera had the same problem, although not quite so severely. Fortunately I noticed it a few days before the warranty on the sensor expired. It took a few months but I did get a new sensor.
I don't have any brilliant ideas for a solution, alas...
I had asked about replacing the sensor however they would not quote on that, the could only advise to buy a new camera. Note this is Andor Technology I am dealing with now since Apogee is no more. AFAIK the Apogee factory in California has been shut down and all operations are now in Belfast I believe.
I would still pay many thousands to get it fixed since a new one is ~14K, but this is not on offer. Maybe they don't even have parts anymore?
EB
completely from left field, but do you think that it might be possible to salvage 3/4 of the chip either by ablating the offending pixels with a medical YAG, by etching the region or possibly even by physically grinding the surface gates off? worst you could do would be to brick the chip completely rather than partially as it is now. If it could be salvaged, 3/4 of a 16803 is still a pretty impressive camera. Sorry if it sounds like a completely daft idea, but you asked.
Sorry to hear this Eric. I am glad I am getting my camera sorted under warrantee. This sort of issue is enough to hurt financially. I hope you can find a path through.
completely from left field, but do you think that it might be possible to salvage 3/4 of the chip either by ablating the offending pixels with a medical YAG, by etching the region or possibly even by physically grinding the surface gates off? worst you could do would be to brick the chip completely rather than partially as it is now. If it could be salvaged, 3/4 of a 16803 is still a pretty impressive camera. Sorry if it sounds like a completely daft idea, but you asked.
Not so completely daft at all ... earlier this week I tried to melt the offending pixel with a 4W 532nm CW DPSS focused down to 50 micron. I thought if I could melt/singe the ITO electrode gates into an open circuit I might only lose the top 666 rows (yes the bad pixel is at 3066,666). Amazingly after several 5 min exposures, no change!?! The damaged area is buried in the multi-column saturated region. I can see the irradiated spot in the microscope where I presume the top layers have been melted, or something, but this does not seem to affect the operation of the chip.
Next week I might try a 4 ns pulsed laser, if I can get my hands on one. The ones we make at 532 nm only focus down to about 400 um, pretty big blast hole. We do make a 1064nm YAG that focuses down to 10 um but I know the Silicon doesn't absorb much at that wavelength, so I'm not sure what will happen there.
Not so completely daft at all ... earlier this week I tried to melt the offending pixel with a 4W 532nm CW DPSS focused down to 50 micron. I thought if I could melt/singe the ITO electrode gates into an open circuit I might only lose the top 666 rows (yes the bad pixel is at 3066,666). Amazingly after several 5 min exposures, no change!?! The damaged area is buried in the multi-column saturated region. I can see the irradiated spot in the microscope where I presume the top layers have been melted, or something, but this does not seem to affect the operation of the chip.
Next week I might try a 4 ns pulsed laser, if I can get my hands on one. The ones we make at 532 nm only focus down to about 400 um, pretty big blast hole. We do make a 1064nm YAG that focuses down to 10 um but I know the Silicon doesn't absorb much at that wavelength, so I'm not sure what will happen there.
Very much a long shot...
EB
crikey, 4w through a 50 micron spot for 5 minutes - would have thought that would fry anything. Amazing that it had no effect on the chip function. Maybe very short pulses could do the trick by vapourising the surface layers through local plasma formation and letting you selectively remove stuff completely - would have thought that a Q-YAG would be OK for that (eg as in LIBS). Be very interested to know how you get on - good luck.
Is the CCD a plug in or is it soldered onto the board?
Hi Terry,
I don't know for sure, however the CCD and whatever it's attached to are in a hermetically sealed chamber (filled with Argon gas), probably soldered shut. Usually they use ceramic or glass feedthrus to get the pins out.
EB
Hi Terry,
I don't know for sure, however the CCD and whatever it's attached to are in a hermetically sealed chamber (filled with Argon gas), probably soldered shut. Usually they use ceramic or glass feedthrus to get the pins out.
EB
Guess that you won't be able to use 1064 YAG then - it would probably damage the AR coating on the chamber window. A 400 micron hole might be a problem with the 532 pulsed laser - suppose it is only about 50 columns though, so not too bad. best of luck.
I'm at the Arizona Science Expo in Tucson. I spoke with Andor on your behalf and with John Alford who is Regional Sales Manager. He said that Andor will replace the chip in your camera and that you need to contact Phil Moore at Andor. Just go to Andor.com contacts. Explain that I spoke with John and that you tell Phil that your camera can be opened and the chip replaced. I hope that is GOOD news for you!!
I have a sun damaged (don't ask) KAF16803 sensor you may be able swap out. Apart from solar sized disks fried into the micro lens structure..which amazingly flat field out...it works OK. PM me if interested.
I'm at the Arizona Science Expo in Tucson. I spoke with Andor on your behalf and with John Alford who is Regional Sales Manager. He said that Andor will replace the chip in your camera and that you need to contact Phil Moore at Andor. Just go to Andor.com contacts. Explain that I spoke with John and that you tell Phil that your camera can be opened and the chip replaced. I hope that is GOOD news for you!!
Peter
Thanks Peter. I have been in contact with Phil Moore and product support at Andor, they were informed of the entire situation, so I am somewhat confused here as to what can actually be done. I will follow up again.
EB
I have a sun damaged (don't ask) KAF16803 sensor you may be able swap out. Apart from solar sized disks fried into the micro lens structure..which amazingly flat field out...it works OK. PM me if interested.
Thanks for the kind offer Peter, I'll keep it in mind, but right now my dilemma is who could actually perform the swapping bit (me!? yikes), once I get that figured out...
Thanks Peter. I have been in contact with Phil Moore and product support at Andor, they were informed of the entire situation, so I am somewhat confused here as to what can actually be done. I will follow up again.
EB
Hi Eric,
Well I'm just reporting what John Alford told me. The jist of it seems to be that most of the cameras that Andor make have a manufacturing process where it is simply impossible to replace the chip but when I told him what camera and chip you had he said there was no reason why your chip couldn't be replaced. He also said that the standard Andor response was to say "no." But, he felt confident that if you explained to Phil Moore that your camera was "different" that Andor should work with you. On the other hand a top person at another major camera manufacturer was skeptical about Andor's willingness to cooperate saying that he had recently received two requests to repair Apogee cameras. I asked him about yours; at first he said OK, but then got a bit nervous saying what if he put in a new chip and the electronics destroyed it. He said he'd prefer to give you a discount on a new camera. You might be able to guess of whom I'm speaking. Contact me off line if you want his name.
Hope I have not muddied the waters but I think some persistance with Andor might get you a result.
That's very sad, Eric! My camera had the same problem, although not quite so severely. Fortunately I noticed it a few days before the warranty on the sensor expired. It took a few months but I did get a new sensor.
My camera was also a U16M and they successfully replaced the sensor, so it is possible...