803T...15min use=LED...back from the dead!?!?!

Hello dudes,

I had a very unfortunate time with my 803t diode yesterday at night. After a full 15 minutes of use (over the past few days) with a max run time of around 30 seconds at once and a current of 124ma@95mw my 803t turned into a LED...

I was baffled to say the least, because I was really babying the diode, and the fact that it was a running a relatively conservative 124ma, I mean I didn't expect it to last forever, but I definitely thought I would get more out of it...

Needless to say I tried everything I could think of to revive my baby: I started with voodoo chants, then it was on to meditation in the hope I could transfer some healing chi to the diode, then I even thought of burying it in an indian burial ground (forgot I dont live in NJ anymore :-/)...

After my intense ritual like ways of reviving had failed I got more technical with it, I thought it must be the batteries but needless to say even with a fresh pair the result was the same and I went to bed a broken shell of a man...it was a cocktail of emotion anger at my luck, despair, sadness...well you catch the drift...

Well today in the morning some blind optimism took over me and I decided to turn on my blu-ray for a last time...

I was stunned...it was working full blast...WTF!?!?!?!? I was always under the impression that once a LED always an LED...but not this diode...

I am currently at a loss as to what happend: there was no overheating (no heating actually set up a really good heatsink), no static (as a former computer freak I am more than aware of the effects of static on e. components), the driver was functioning as it should (though I didnt use a multimeter, cause this was supposed to be my treat after a hard days work) etc.

Has this ever happend to anyone or am I now the proud owner of a zombie 803t (voodoo chants)...based on my xp. atm, I would suggest everyone with busted 803t's to try and fire them up again...if it doesn't work initially the voodoo chant should solve it???


Thanks
brtaman

This happened to another member who I spoke to. It turned out it was driver related. He was using the flex drive from dr.lava. Are you also using the flex drive? If so, what is your input voltage? This other member was using an input voltage that was a little bit too high for the driver and the same thing happened.

I bet your batteries or power supply had a bad connection when you thought ya had turned it into a LED. Probably a fluke thing

Oh... and you forgot to bury a frog facing north (talk to dave for exact procedures) when you were doing all your chantings and good-luck rituals ;D

Hmm the old frog burial ritual, thought about it but that is too far on the dark side even for me ;D

The thing is however that the batteries are fine at the exact voltage that the driver is supposed to run at, and they were also changed. I doubt it was the connection...

I guess that it was infact just a fluke...?

Thanks
brtaman

brtaman said:

Hmm the old frog burial ritual, thought about it but that is too far on the dark side even for me  ;D

The thing is however that the batteries are fine at the exact voltage that the driver is supposed to run at, and they were also changed. I doubt it was the connection...

I guess that it was infact just a fluke...?

Thanks
brtaman

Click to expand...

what host is it in? I've had some really weird host-related connection issues before. Some of which made the diode behave just like yours

Hey,

Its a non-standard host, it looks alot like a lightsaber, cant find the link atm, but I was planning on making a tutorial on it, cme out pretty nice actually, however while I doubt it was power supply related, that is the only thing that could be a possible explanation. (the host itself is really simple, and either its full or no contact, that is what bugs me...


Thanks
brtaman

Well, the diode can't die and come back from the dead. A zombie puts out 0.1mW.. It's not even measurable most of the time. If your diode works, then nothing happened to it.

Were you opening up the module perhaps? If so, you could have caused a short or a loose connection. My driver was never meant to be fiddled with. I didn't really try to make it user friendly, because it was never supposed to have users other than me.


Other than that, it could only have been:
A connection issue
- Connection issues can come from wires, bad contacts between the parts of the host, or the switch

Voltage too low
- but in this case it would start blinking, or simply stop working

A component failing
- but it wouldn't come back to life in this case

Voltage too high would have overdriven and/or killed the diode, as it is a boost only driver, so this couldn't have been the problem. As i told you, never use more than one Li-Ion, or two to three 1.5V batteries. One Li-Ion is better.


I think it must have been a connection issue somewhere. If it happens again, send it back to me, so i can inspect it.

dirty battery connections, failing clicky switch, or cold solder joint. :

Yeah. A diode can't come back from the dead.. And zombies are not diodes anymore.


Oh, and Brtaman.. There is a simple way of checking if the diode is really dead. You have to replace the tailcap (don't know what your host is) with your DMM in a current measuring range of 2A or more.
- If the driver is pulling current from the battery, but the diode is not putting out light, it is dead.
- If it's not drawing current, you have a bad contact somewhere in the body.
- If the diode suddenly comes to life, when you replace the tailcap with a DMM, you have a bad switch.


Oh, and the current you would measure in this case would be MUCH higher, than the current through the diode. It's a boost driver, don't get scared by that - the current through the diode never changes. When the battery voltage is high, the current draw from the battery is only slightly above the diode current. The lower the battery voltage, the higher the current draw from the battery (so that the power (U x I) going in stays the same)..

With a linear driver the current draw from the battery is the same as the current through the diode on the other hand.

Hey guys,

Ive been so happy that my blu-ray is now completely functional I completely forgot that about this thread.

Yeah you guys were right it was a connection, the problem was with the host, it was a problem that I wouldn't have thought would even create a problem but I got it sorted, thanks for the support.

Oh and thanks Igor for the useful tip, I will definitely have to keep that in mind on my future builds, instead of creating panic threads such as this on


Edit: Here is a pic of my "lightsaber" blu-ray...if anyone is interested I can make a tutorial, its really simple just a bit time consuming as far as the heatsinks go.




Thanks
brtaman

So can you tell more specifically, what part of the host was the problem?

Hmmm,

Its pretty hard to explain, but i'll try:

The host is basically just an aluminum tube when you take it apart, the thing that seperates the battery compartment and the light compartment, is just an aluminum disk. This disk provides the - contact (due to its contact with the board.), the + is provided by a wire connected to a "pcb" well just a board with a battery+ contact point on one side to which the wire is connected to on the other side. Well this disc fell out and was offset (not in the indent provided for it), which is why nothing changed when I replaced the batteries, but I guess that in the morning it was left on it side and provided just enough contact to run the diode...I have since used the age-old trick of applying a dab of CA to make sure it stays in place, his has solved the problem.

Hope that was somewhat understandable?


Thanks
brtaman

glad u got it my 803t diode was working but then went dimm so i tryed many diffrent things but would not work, so i hooked it up to a 9v batterie and now it works fine :-/

Oh my god..  :-?


Define "fine". How much power is it putting out?

Thanks jake, I'm also happy that it is working full blast...tons of fun poping baloons hehe

Yeah but 9v? what driver are you running? I remember reading a post in this forum stating that once a diode requires more and more voltage it is on its way to becoming a led?

What sort of ma were you running through it?


brtaman