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Re: Testing bridge rectifier
A bridge rectifier is simply 4 diodes arranged like this:
Each diode is supposed to have a forward voltage in one direction only, so on diode mode, if you measure with the probes one way you get the voltage drop shown on screen , if you invert the probes you should get nothing.
You have
DC - ─►|─ AC 1
DC - ─►|─ AC 2
AC 1 ─►|─ DC+
AC 2 ─►|─ DC+
So:
red on DC- , black on AC 1 and AC2 and you should have 0.4-1.2v both times. Invert probes, nothing.
black on DC+, red on AC1 and AC2 and you should have 0.4-1.2v both times. Invert and you should have nothing.
Basically like he says, but in less confusing way. And DO NOT test the rectifier while the power supply runs!
Depending on current the bridge is rated for, the voltage shown will vary. Regular diodes are around 0.5-0.6v but high current rectifiers can show up to around 1.2vAttached Files -
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Re: Testing bridge rectifier
Can I test a BR in circuit or do I have to remove?Comment
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Re: Testing bridge rectifier
I always test it out off the circuits.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Hi all, a newby question about a bridge rectifier I'm trying to identify.
I'm in the midst of reparing a battery charger in work which went pop, The bridge rectifier has shorted and took out a couple of other components. The rectifier in question has a part number KPB305G, and it looks like it's obsolete. Does any one know what I could replace it with?... -
Hello
My Fujitsu Esprimo Q556 motherboards blew up. At least fuse, bridge rectifier and capacitor got damaged. I have changed fuse and bridge rectifier (DF1508S), but I don't know what capacitor it is (picture). I know that capacitors size is 47nF, but I don't know other specs for it. Can you help me to choose right capacitor for my motherboard?
There is 240V AC on input side of bridge rectifier and 340V DC as output on capasitors side.
Thanks.... -
I have a 40 volt AC transformer that I put a bridge rectifier on, and I wanted to see the input signal and the output signal on the same screen on my scope, so I set one channel up with the test lead on one side of the input and the ground lead on the other side of the input, then I used another channel on the scope and clipped the test lead on the positive side of the output then the ground on the negative side of the output.
When I connected the transformer to power, the wire that was connected between the ground lead on the second channel and the negative side of the bridge rectifier... -
This is my first attempt at troubleshooting a board like this, I know I could just buy a new board but I'm curious to figure out how this works. I've been testing different components in the evenings this week and I think the problem is with the IC failing to start up for some reason. When the board is plugged in there is no standby voltage.
Then today it randomly sprung to life like a zombie but shortly died thereafter. I have no idea why it would have done that and its the first time I've seen it running. I discharged capacitors on the board last night, then it was sitting today.... -
Hi,
I'm learning about motherboard repair and I believe I've traced the issue down for the South Bridge on the particular motherboard I'm working on. My path of concluding that:
- There's no sign of any attempt to power on when pushing the power button.
- No PSON signal is reaching the 24-pin ATX connector.
- The Super IO chip is receiving the PS_SWITCH signal from the power button and is relaying this signal back to the South Bridge.
- The Super IO is not receiving the S_SLPS#_R signal back from the South Bridge
- If I pull the Super IO S_SLPS#_R pin...
Comment