Ok... Checked all cap and there all the right way around. Stumbled on a dry joint and sorted that out. Fired it up and all lights come on and fan is now spinning. But after a couple of seconds the PG light goes out.... Have checked the voltages and all seem good. Traced the green wire back and it comes to a small daughter board. On which was a dodgy looking transistor and resistor, which checked out ok. But next to it was a TN431 Shunt regulator. That seems suspect (if you can believe [url]http://www.jestineyong.com/how-to-test-adjustable-precision-shunt-regulator-tl431/[/url])....
I think I must have soldered the cap that went bang wrong. Which started me on this journey...
I'll check all the joints in question and near by caps. Good idea tracing back from the green, I'll have a look. But this circuit seems to be on the mains primary side, so not sure it's going to be that obvious.
Oh yes.... No white wire. And I plugged in a good Antec Earthwatts 650w (also without a white wire) and no -5V So it's just the PG light and no fans...???
I've unsoldered the transistor and run it through a simple DMM test and it seems ok And I've even checked the signal diode in the hot spot, again ok. All the pcb tracks look ok too, I've had it under a big magnifier.
Well that didn't work...... I tried a new L7818CV and it's still the same One thing I was wrong about though was, It's the -5V and the PG lights that doesn't come on, not the 5VSB. Also the fans don't spin, probably run from the -5V...!!! Any idea's would be most welcome.
Not sure exactly what you want to see, but here's the offending area. I followed a post elsewhere where someone had pictures of the same hot spot. And the concensus of opinion was the above resistor was the cause it but all was well. I have resoldered said resistor as the joint looked a bit sad.
You can see from the top picture some of the debris of exploded cap (I must have had the polarity wrong...!!!). Needless to say this picture shows the replacement in position.
It was the 5VSB and the PG light that failed to light on my budget eBay (from China must be good) PSU tester. My intension was to fire it up with said tester then run along the contacts with DMM before I tried it on an old Mobo. But things didn't go to plan.
The PCB traces look ok although there are points of discolouration where a resistor has been a tad hot. But they where there before and I did read somewhere on this forum this is normal for that part of the board.
Hi all, I have an Antec Truepower 2.0 550W PSU which wouldn't start up. Took the cover off and found some erupting caps, so decided to replace the lot.
All went well until I tried powering up again...... Turned on the power and all is well. Applied the PSU tester and nothing, and then POP..!!! C44 exploded.
I have no idea why it went, I can only imagine I had the polarity wrong. Can't really tell though, as there is nothing left of it. So I replaced it and tried again. This time the PSU fired up ok, but I have no 5V.
No, I unsoldered it from the board then measured it. I was thinking maybe to go for a 5W ceramic replacement. At least it should handle the heat a bit better.
Spookie..... Thanks for that, if it'll work like that I'll leave it too. Or 2nd thoughts..... As it works I can measure the value an replace it. Ah-ha I love it when a plan comes together.
Hi all, I have an Antec Truepower 2.0 550W PSU which has given sterling service for 4 years but now need's the fuhjyyu (not sure I've pronounced that right ) caps replacing. This is a UK unit and seem's a bit different to some of the pictures I've seen on this forum. But my problem being R117 has got a bit hot and I'd like to replace it. But the colour bands have burnt off (see picture). I don't suppose anyone has the lid off of one of these at the moment and could let me know what value (colour) it is?...
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