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Bemused  
#1 Posted : Thursday, May 10, 2012 3:17:43 PM(UTC)
Bemused

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Hello guys, first problem and first post here.

Finally got around to getting some power onto my Buffalo III and have a little problem with led D1 not being lit on first energisation.
It has 0.33 volts across it and measure 0.36 in both directions with the multimeter set to diode test.

Now I am not at all expert but it looks like it is no more than a faulty led.
What are your thoughts and if the led is considered at fault could you recommend a replacement from RS components.

Many thanks
Tony Jukes

Brian Donegan  
#2 Posted : Thursday, May 10, 2012 6:09:25 PM(UTC)
Brian Donegan

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Unless you have had some sort of mishap, the LED should be fine.

Which Trident is having in issue? If it is VDD (1.2V), then it is likely you are not delivering enough current to the Buffalo.

Also, double-check you have the Tridents in the correct locations.
Bemused  
#3 Posted : Friday, May 11, 2012 7:30:17 AM(UTC)
Bemused

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Hello Brian, I do not believe there has been a mishap the whole lot sat in your jiffy bag for some months, failure occurred on first power up yesterday.

Yes it is the VDD (1.2V), the Placid HD was set to 500mA CCS and output from Placid was 5.25 volt on load, I did try 550mA and did check the Tridents were in the correct locations but will double check latter today.

It is just the one led (D1)

I can say that using a multimeter set to diode test with the Trident removed I did not get comparative readings between D1 and D2, the reading was 0.36 in both directions.

Many thanks
Tony Jukes
Bemused  
#4 Posted : Friday, May 11, 2012 1:04:33 PM(UTC)
Bemused

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Ok I triple checked that the Tridents are in the correct locations.
Bemused  
#5 Posted : Friday, May 11, 2012 1:54:50 PM(UTC)
Bemused

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Ok so I thought to measure the volt drop across the resistors. During the measurements the D1 led kept blinking on, finger touching around R4, R5 and R9 lit the led, I re-flowed the board, still same problem, I noticed the body of R4 was touching C3 so I raised R4 above the board a little and bINGo.

The Trident is working fine now.

Many thanks
Tony
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