Schematic for a JDSU Mod 10075248 Controller ? / Possible repair ?

[Jem]

Hi

Does anyone have a schematic for a JDSU Mod 10075248 Controller? This is matched to a small 20mW SLM 532nm laser, model 21006959-001.

Let's just say that I had a little 'accident' with it and something inside went Pffft and emmited some smoke

I'll try and take a photo of the offending circuit board and component later. There is of course no guarantee that it's just the one component that's blown, it could be the whole thing. This is one reason why I hate electrical stuff. I had just bought a new variable output power supply unit and connected it up to this little beauty, I set it for 5 volts and switched it on. The laser came on and I though "great, my nice new PSU works", then without me touching anything something inside the new PSU clicked (maybe a relay?), the output voltage shot up and the laser went out , then there was the smell of doom from the Laser controller. Guess I should have tried the PSU out on something less important first, ah well...

In the meantime, if there is anyone here who is an electronics wizard and would like to take a shot at repairing this for me i'd be eternally grateful as I had great plans for this little laser. I figured i'd need a circuit diagram first though.

Cheers

Jem

[FourDee]

Well, I hope for your sake that the microchip µC in the center of your third picture had its supply lines protected ...
Otherwise there is no repairing this thing without the proper firmware ...

[shrad]

with a bit of chance, there's a switching part between the µC and the power input line, and the fried component took all the surge into short-circuit

fingers crossed

[Jem]

Here's a picture that shows the burned out component.

[weartronics]

then without me touching anything something inside the new PSU clicked (maybe a relay?), the output voltage shot up and the laser went out

Oh no! The variable output PSU normally uses relays to jump between transformer taps, so that the linear stage never has to regulate too many volts away as heat. If there isn't enough output capacitance, there will be a big spike every time the PSU jumps taps. This type of power supply isn't really suitable for powering sensitive equipment like that JDSU directly. In the future, I suggest you put a big filter capacitor on the PSU output and use your own regulation stage, or just buy a regulated plug-pack type PSU instead.

As for repairing it, forget the schematic. You can try replacing any obviously damaged components in the power supply section, and you don't need any schematic for that. If the damage extends beyond the power supply section, the schematic won't help you anyway because that board has things like microcontroller with proprietary firmware. It means that you can't replace it with standard parts, the chips have to be individually programmed by JDSU. I hope you are lucky and replacing some power supply components is enough to fix it.

[shrad]

hard to tell, it could be a diode (doubt it as they usually are bigger), a capacitor (doubt it ever more), or a resistor (very plausible guess)

anyway, a macro photograph would be needed to see any details, like perhaps a trace of the painted number of the said resistor or a bit of intact component body underside which would help to tell if it's really a resistor

the chance is it is a 2-wire component, which in the SMD world is one third of the work... second third would be the body colour, and third third would be determining the component's value (hardest part of the work)

not to say it could have been a chain-pop and other components are fried, but it seems they would also have popped or smoked if they had been part of the chain

does the fried component show a short-circuit or not? is one of the wires tied to the gound plane? or the positive power supply line? if you can, try to trace the wires and verify closely the connected components

[Jem]

Thanks for the information. It sounds like it's probably fried

Sadly, I don't have the knowledge or the equipment to repair this. I need to find someone who'll have a go at it for me. Alternatively...

Would it be possible to get hold of another controller?, what's the chances of the actual laser head being fried?

As for the Variable PSU, it's one of these http://cpc.farnell.com/caltek/psm3-5...30v/dp/IN05511

From what you've said it doesn't sound suitable for powering lasers. It's just that I've got quite a collection of lasers that all require different power and I thought this would be o.k. Any suggestions as what would be best if this one's no good?

Cheers

Jem

[Jem]

hard to tell, it could be a diode (doubt it as they usually are bigger), a capacitor (doubt it ever more), or a resistor (very plausible guess)

anyway, a macro photograph would be needed to see any details, like perhaps a trace of the painted number of the said resistor or a bit of intact component body underside which would help to tell if it's really a resistor

the chance is it is a 2-wire component, which in the SMD world is one third of the work... second third would be the body colour, and third third would be determining the component's value (hardest part of the work)

not to say it could have been a chain-pop and other components are fried, but it seems they would also have popped or smoked if they had been part of the chain

That one component looks to be the only one that's fried, everything else *looks* O.K.

Unfortunately, it's *really* fried bad. There's no chance of telling anything from the component.

does the fried component show a short-circuit or not? is one of the wires tied to the gound plane? or the positive power supply line? if you can, try to trace the wires and verify closely the connected components

Bear in mind here that you're talking to an absolutely incompetent electrical numpty , you may as well be talking another language

That's why i'm looking for someone to have a go at repairing it for me.

Cheers

Jem

[shrad]

if nobody else wants to give it a try, why not, and we're from the same side of the ocean

however, I cannot guarantee any success and can only try to repair it...

what is sure is I'm trained at soldering/unsoldering SMD components and I know them, and if I know the type of the blown out component, I might find a generic value from the surrounding components datasheets which will work

the best waywould still be to find a replacement schematic (and pray that no spike reached the head)

[hologeek]

Hey Jem,

Don't feel too bad I did the exact same thing a while back! I was eager to see if they were working, and being unsure of their required voltage I used a variable switching power supply. Lesson learned. I still have the broken one, but the component that burned out on mine is different than yours. I just got back from being out of town for the holiday, but will take a look later and see if I can help. At least I can identify what burned out on yours, but it may be more than that though...

-George