150mw Bluray Diode : Test to Destruction!

Are these the ones for $70 on ebay?

The four diodes in my graph were from the same group buy.

About the differences, do you remember the shortage of the supply of blue diodes a few years ago? I think the factories were loosening the production process to get more good diodes (less discarded diodes) for lower prices. Think about this: If they would want to make 90mW diodes and do it the classic way, they would tune the machines to produce 90mW and those that are <80mW or >100mW are discarded (or sold as 50mW, 70mW, 110mW, 130mW, etc. respectively). In the case of blu-ray (the drive factories wanted only 90mW diodes), that would mean a very high discard percentage (or low production capacity). The alternative, which I think they chose, is to produce, say, 150mW diodes, and discard only those below 80mW, so the discard percentage drops drastically, bringing either or both the overall price down by several magnitudes and procude more diodes in the same timespan.

By now I have a lot more test results (2 group buys later). Here's the graph:



Here's the thread post with a lot more data and information

daguin, here are some QR-codes.



These are digitally post-processed from macro photos like these:

I started thinking after reading this thread. As my weak diodes are almost useless anyway I gave it a try and increased the current through the knee and above.

I just found out that one diode I deemed weak actually has some serious mode issues and is a lot stronger. I will immediately test the other weakies as I am not so afraid anymore of blowing them.

[edit] work in progress moved here: http://www.laserpointerforums.com/forums/YaBB.pl?num=1214268330/60#75

Bill's seems to be different from each of those. :-/

Gah! My little QR reader can't read it. It does appear to be different (visually). I'm going to pull one out later today. I'll look at it with a loop.

Peace,
dave

Spyderz20x6 - This was a cheaper diode off ebay, months ago, cost about $50CDN with shipping. Haven't found it again.

I spent some more time with the photos of the brands.  After visually comparing them I am more convinced that BillG's diode is the same diode as the one that comes in the PHR-803T sled.



ZomB's photo shows more "bleeding" of the dots and BillG's shows some different "bleeding", but the patterns are too close to show significant difference between the QR Codes.  At a minimum the QR Codes share many more similarities than they display differences.  I adjusted the diodes' orientation (in the pictures) so that they were the same.  Even the placement and orientation of the brand is the same.

Peace,
dave

The brands on my diodes look the same as the one on the left. The combination of harvested lenses I'm using for making macro photos blurs it a lot.

I don't know, those 2 look almost completely different to me. :-/ Only the bottom right corner seems to be the same.

How much was $50CDN when you got it?

Switch - The CDN & US dollars were nearly equal back then.

The heatsink that the diode was in is a different shape and different alloy than the heatsink used in PSXBOY PHR-803T assemblies that I have taken apart. This was a lighter weight, easily fractured alloy. I thought that it might be nearly pure magnesium, so I gave it a touch of oxy-acetylene flame and it lit, burning with a bright white light. A simple twist with two pliers instantly fractured it from the diode.

billg519 said:

Switch - The CDN & US dollars were nearly equal back then.

The heatsink that the diode was in is a different shape and different alloy than the heatsink used in PSXBOY PHR-803T assemblies that I have taken apart. This was a lighter weight, easily fractured alloy. I thought that it might be nearly pure magnesium, so I gave it a touch of oxy-acetylene flame and it lit, burning with a bright white light. A simple twist with two pliers instantly fractured it from the diode.

Click to expand...

I wish we had some pictures.  The method you describe here for removing the diode from the heat sink is how I have done it for a long time.  What did the heat sink on the "older" ones look like?  How were they different?

Peace,
dave

Switch, it's the pattern that differs for every diode, but the way the symbol is etched (what one pixel looks like) is the same on both diodes, even is mine is too blurry to see in the photos)

great chance these are Sharp diodes, probably either GH04P21A2G or the more general GH04P21A2GE. Either way, these diodes are not exclusively used in HD-DVD for Xbox 360.