Red Build Attempt #2

[flogged]

This weekend I'm hoping to build another brick laser. This one, as my other recent attempt, from a failed DVD drive. The diode is from one of my two cheap Lenovo desktop computers. The tray on the internal optical drive began eject and close repeatedly.

I had to remove the drive and its been collecting dust for over a year.

Here's a picture of the drive -

..And the diode, destructively extracted

The diode is another flatpack, however the (holographic?) optical element on the front the diode is removable. It's a press fit the diode housing. Open can diode. So I'll hopefully be able to focus this one. Off to RadioShack for parts. I ran out of Meredith optics, so AixiZ for this one.

 

[flogged]

Failure. Unable to unsolder circuit board, rear of diode. Legs ripped out. In picture I'd scoured down back of diode, however could not get enough purchase to reattach legs.

I'm now moving on to the internal drive in my 2005 Compaq. Very exciting, I know.

 

[flogged]

Here are some images from the Compaq's internal drive - an HP DVD Writer DVD 400i

Here's the sled. Anyone know these diodes? Extraction will not be easy

 

[crazyspaz]

the ribbon cable closest to the bottom, that attaches at a circle with solder on it is the diode. Heat up the solder, pull the ribbon cable off, then use some pliers to pry that aluminum block out that has the diode in it. Or, just use some clippers and cut the block out, they are pretty soft. Then either use pliers or clippers to bend/snip the block in half so you can pop the diode out.

Also don't throw out the rest of the sled, there are some fun optics in it mainly the PBS (little cube in the middle)

 

[flogged]

I believe the outermost diode on the sled's the red one. At least the lens coatings for it are blue. It's got a 'L8Y424L' on the side of the can. Nice sealed diode.

Anyone know the pinout??

 

[Eudaimonium]

All 650nm reddies have the same pinout.

Though that what you have may, or may not be red diode, can you try extracting the other one?

Red diodes typically have blue-tinted reflection off their windows, and the base of the diode from which the pins protrude usually has one more minor concentric ring around all the pins. Kinda tough to explain but you'll recognize it when you see it.

 

[flogged]

F*CK!!! Blew the diode. Lased brilliantly at 50mA for a moment or two before the gater clip slipped and the cap popped it.

These closed can diodes, which are good for pointers, appear to be becoming scarce. HP drive was 10 years old. Sigh.

 

[flogged]

Rampage continues. LG portable burner -

 

[flogged]

Oh no. Here's a picture of the diode. Another flatpack. And, judging from the reflection off the diode window, another holographic lens designed to be near sighted. Sigh. I HATED f*cking up and killing that last diode. I don't have any more old drives.

 

[flogged]

Very bad luck. Only the IR side of this diode fired. So three wrecked diodes in a row, the worse luck I've ever had. The HP sealed diode was a victim of the 'DDL' circuit. One of the gator clips attached to the diode, while I was metering it, moved.. the capacitor then killed it. A known problem with the 317 protection circuit, at least until everything is soldered into place.

 

[The Lightning Stalker]

I have killed diode after diode before, and feel your pain. Sometimes it's best to stop when things start
going wrong. It's not easy to do though, I know. It's like a drug and you keep looking for that next
"high."

With diode extraction, the two main problems are mechanical and electrical. Wear a static strap at all
times and work over a grounded mat if you have one. The mechanical part is the most challenging. The
best way is to flex the heat sink with big pliers, channel locks, or vise grips until it snaps. Some are
stronger than others. If it won't snap, it's better to try pushing (pressing) than pulling. As you have
discovered, the pins on a diode are fragile. Pulling will only work if the diode is already very loose.

To alleviate the slippage problem, I recommend using test hooks instead of alligator clips. They also
get between the tiny pins easier without shorting out.

Don't feel bad. Even the veterans at this make mistakes and run into problems. We are often fighting
against corporations who are not keen on having laser diodes extracted from their products. I'm sure I
will pop a few more even knowing what I know.

Do be careful with the IR. 780nm is in a hole where most safety glasses do almost nothing. What
appears to be a faint glow could be powerful light capable of causing eye damage. This is made worse
by the microscopic emission point. Don't ever look at the front of any laser diode. Pick up some 580-
760nm laser safety glasses at Survival Laser if you have not done so already.