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Capacitor question

Hemlock_Mike

Hemlock_Mike

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Gus --

I love the fact that you are getting an education in board level troubleshooting. Priceless :) Many here will never understand the basic electronics you are learning --- sad........
When I got into electronics, It was tubes and 300 to 2,500 volts!! THAT is an education!!
Be careful in this --- I think you are on track.

Mike
 





Benm

Benm

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When I got into electronics, It was tubes and 300 to 2,500 volts!! THAT is an education!!
Click to expand...

Very effective in teaching you not to put your fingers in places they aren't supposed to be in ;p

With the Diode under test connected with its Cathode (the Bar end)
towards the Neg of the battery... the LED should come "ON".

With the Diode connected in the reverse direction the LED should be "OFF"
Click to expand...

I would have to object to the reverse polarity test here. I doubt you will destroy any diodes in real life, but if the leakage current of the led exceeds that of the laser diode, you could reverse-bias it beyond specification (typically 5 volts maximum).
 
GooeyGus

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I got my new rectifier diodes in the mail yesterday. I'm going to commence surgery in about 10 minutes, I'll let you know if the problem is solved when I get back!!
 
lasersbee

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Before you start your surgery... I would test the old rectifiers against the New ones just to have a base line and see if the old ones are actually blown.

Just my $0.02
 
GooeyGus

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lasersbee said:
Before you start your surgery... I would test the old rectifiers against the New ones just to have a base line and see if the old ones are actually blown.

Just my $0.02
Click to expand...

thats my plan :cool:
 
GooeyGus

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its all back together.... AND IT WORKS!!! One of the diodes was bad, the other MR2404 wasn't bad, but I replaced it anyway since I had new ones... might as well. Good news it it didn't blow the breaker when I plugged it in. Then I hooked the head up to it, and it lased just fine! I cranked the power up to 10.5A after it warmed up and it performed like nothing ever happened. Thanks everyone for all the help! :cool:
 
daguin

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GooeyGus said:
its all back together.... AND IT WORKS!!! One of the diodes was bad, the other MR2404 wasn't bad, but I replaced it anyway since I had new ones... might as well.  Good news it it didn't blow the breaker when I plugged it in. Then I hooked the head up to it, and it lased just fine! I cranked the power up to 10.5A after it warmed up and it performed like nothing ever happened. Thanks everyone for all the help!  :cool:
Click to expand...

You are a PSU god

Peace,
dave
 
lasersbee

lasersbee

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GooeyGus said:
its all back together.... AND IT WORKS!!! One of the diodes was bad, the other MR2404 wasn't bad, but I replaced it anyway since I had new ones... might as well.  Good news it it didn't blow the breaker when I plugged it in. Then I hooked the head up to it, and it lased just fine! I cranked the power up to 10.5A after it warmed up and it performed like nothing ever happened. Thanks everyone for all the help!  :cool:
Click to expand...

Great.... now you have some spare diodes for the next time... you did buy four??? :-?
 
rkcstr

rkcstr

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Awesome! Glad it was a simple fix :cool: Reminds me of a high end home-theater sub I bought from a guy a few years back. Thing cost like $600 new, I bought it for $80 because it didn't turn on anymore figuring the amp may be blown and I'd just repair it. Turns out the problem was simply a blown resistor... an order went into Mouser, cost about $7 and it was fixed, though paying the shipping cost for just a resistor sucked (well, I bought more than one), lol.
 
Hemlock_Mike

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Gus -- Good you replaced both -- often time in solid state, when one lets the smoke out, the other gets hit and will go soon.

Congrats on learning board level testing AND you still have all your fingers :D

Mike
 
T

Things

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Its kinda funny how all th simpler components manage to die. when you think about the complexity of a resistor vs something like a PIC, there is a huge difference!!

What Mike said is always a good rule of thumb. If something dies, there is a good chance something else will also die after a while.

Good job!
 
Cyparagon

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That's fantastic!

Hemlock Mike said:
often time in solid state, when one lets the smoke out, the other gets hit and will go soon.
Click to expand...

He couldn't be more right in this case. Current is always passing through exactly two of the four diodes in a full-wave bridge rectifier at any given time.
 
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