12V rail is not on ?

[bianchi77]

Re: 12V rail is not on ?

Measuring with ohm...SBL1040
Forward bias = 1K1
Reverse bias = OL

Diode in the middle
Forward = 6M1 and reverse = 4M5

with diode on DMM
SBL1040 = 0.17V

Diode in the middle = 0.45V...

Any idea from those information, I suspect my diode in the middle is opened ( faulty ) but how come I can get 0.45 V ??

[bianchi77]

Re: 12V rail is not on ?

D14 is the diode with 2 pins and kathode connected together

[bianchi77]

Re: 12V rail is not on ?

Can I replace D14 with SBL4030 ?

[CapLeaker]

Re: 12V rail is not on ?

Which link ?

your post #13. Hit the reply button and it is there, then it disappears.

"
http://i129.photobucket.com/albums/p231/picture_77/IMG_20160721_181745_zpsckctjrrx.jpg"

[CapLeaker]

Re: 12V rail is not on ?

What is written on D14?

[bianchi77]

Re: 12V rail is not on ?



?

[bianchi77]

Re: 12V rail is not on ?

I can't read what is written on D14...
I want to change it with SBL3040....possible right ?

[bianchi77]

Re: 12V rail is not on ?

http://www.aliexpress.com/item/Silic...08.0.60.XG0ffQD14 = FR302 diode...

[CapLeaker]

Re: 12V rail is not on ?

I think you are getting a bit ahead of yourself. The FR302 is an axial diode and only handles 3A. The SBL 3040 is 40V and 30A.

The D14 is on the 3.3V rail? You should be putting up some pictures, so we can actually see something.

[bianchi77]

Re: 12V rail is not on ?

from datashieet I see FR302 Voltage drop = 1.2V I got only 0.4V,
I suspect it's faulty

[bianchi77]

Re: 12V rail is not on ?

and for SBL1040, it's 0.55V from datasheet, and I got only 0.1V...

The three rectifiers are faulty I reckon, any comments ?

[bianchi77]

Re: 12V rail is not on ?

D14 on 12V rail..

[bianchi77]

Re: 12V rail is not on ?

Schematic :
http://www.elsys.biz/download/files/...0Y-B200ATX.pdf

[bianchi77]

Re: 12V rail is not on ?

3.3V, -12V and +12V

[CapLeaker]

Re: 12V rail is not on ?

Schematic :
http://www.elsys.biz/download/files/...0Y-B200ATX.pdf

All I get is 404 error.

[bianchi77]

Re: 12V rail is not on ?

https://cdn.badcaps-static.com/pdfs/...83951b6882.pdf

Try that?

[bianchi77]

Re: 12V rail is not on ?

I Hvn t checked C22 C23 C27 C32

[stj]

Re: 12V rail is not on ?

if you see a diode with a 0.1v voltdrop - put a new battery in your meter.
a low battery messes with the readings before the meter notices it's low.

[fzabkar]

Re: 12V rail is not on ?

The forward voltage drops in the datasheets are those associated with the diode's rated current. Your multimeter probably outputs only 1mA on the diode range and even less on the resistance ranges. You should be using the higher resistance ranges to confirm whether a short exists.

See the attached I-V characteristics and notice the forward voltage at 0.01 A (= 10mA). Your meter readings should be less than this.

[bianchi77]

Re: 12V rail is not on ?

The resistance I measured 6M5 and open line...