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Old 1st February 2010, 02:05 PM   #1291
jleaman is offline jleaman  Belgium
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Quote:
Originally Posted by cjkpkg View Post
***insert facepalm***

R13 - I ordered 47.5 ohm instead of 47.5k ohm...rookie...

who knows what else I fried as a result...
Probably nothing

Make sure you short -in to gnd also if you are not using balanced
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Old 1st February 2010, 02:08 PM   #1292
Tea-Bag is offline Tea-Bag  United States
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if you have one, a 68.k or 100k will work, but will get hotter. yep, no bias.
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Old 1st February 2010, 02:38 PM   #1293
cjkpkg is offline cjkpkg  United States
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I just placed an order to mouser...I had to get some other items as well...I should be able to fire it back up Wed or Thu for some testing...
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Old 4th February 2010, 01:55 AM   #1294
cjkpkg is offline cjkpkg  United States
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OK...getting very frustrated...still no voltage across the source resistors...fixed R13 with 47.5K and nothing...

No voltage across R1 D1 or the source resistors. How could I check Q1,2,and3? I don't know what to do next...
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Old 4th February 2010, 02:12 AM   #1295
cjkpkg is offline cjkpkg  United States
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Oh...and I'm getting 14.8V on the output...
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Old 4th February 2010, 12:30 PM   #1296
cjkpkg is offline cjkpkg  United States
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I tried 2 more things last night...
1. finished adding the R to my PSU...3-0.47ohm resistors per rail (thought maybe the temporary jumper wasn't passing enough current???)
2. replaced the ZTX450's thinking maybe they got fried??? (unsure how to properly test though)

Still getting 17.4V per rail which is good...but why the @#$% is there no current passing through the source resistors and why is there no voltage across D1 and D2?????

Still getting about 17V at each leg of the source resistors to ground.

Once funny thing is that I am getting about 5V at D3...D5 is getting voltage...cant remember exactly but maybe it was 14 or so...

I even replaced the FET's with 2 spares I had not used just in case they blew the first time I fired it up.

This, I guess, is leading me to Q1,2,and 3...I do not know how to test them and by ruling almost everything else out leads me to believe that these may be the cause of my great frustration. Is there any simple DMM check I can perform on them for at least some type of rudimentary GO/NO GO without having to try and remove them??? I have a greenlee DM-20 that does have a diode setting.
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Old 4th February 2010, 02:09 PM   #1297
jleaman is offline jleaman  Belgium
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Quote:
Originally Posted by cjkpkg View Post
I tried 2 more things last night...
1. finished adding the R to my PSU...3-0.47ohm resistors per rail (thought maybe the temporary jumper wasn't passing enough current???)
2. replaced the ZTX450's thinking maybe they got fried??? (unsure how to properly test though)

Still getting 17.4V per rail which is good...but why the @#$% is there no current passing through the source resistors and why is there no voltage across D1 and D2?????

Still getting about 17V at each leg of the source resistors to ground.

Once funny thing is that I am getting about 5V at D3...D5 is getting voltage...cant remember exactly but maybe it was 14 or so...

I even replaced the FET's with 2 spares I had not used just in case they blew the first time I fired it up.

This, I guess, is leading me to Q1,2,and 3...I do not know how to test them and by ruling almost everything else out leads me to believe that these may be the cause of my great frustration. Is there any simple DMM check I can perform on them for at least some type of rudimentary GO/NO GO without having to try and remove them??? I have a greenlee DM-20 that does have a diode setting.


Post pictures please take a hand full so i can see i have a good eye
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Old 4th February 2010, 02:45 PM   #1298
cjkpkg is offline cjkpkg  United States
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What other angles would be helpful other than the 2 above...underside maybe?
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Old 5th February 2010, 12:41 AM   #1299
cjkpkg is offline cjkpkg  United States
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I'm about to throw in the towel...I cant take this anymore...I have checked and checked and checked...nothing makes sense and I'm about to pitch the whole thing...

This is the most frustrating project I have ever worked on....
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Old 5th February 2010, 02:56 AM   #1300
pchw is offline pchw  United States
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Take a break and come back, clear mind sometimes helps.
Use the attach schematic to measure the voltage acoss the IRF9610's and the ZTX. Notice that the component names are different from Brian's board, but when you look at both schematic together, you can tell which is which. Hopefully, this will help you to isolate the trouble area.
Attached Files
File Type: pdf aleph30.pdf (29.9 KB, 110 views)
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