Emerson LC320EM2 blown fuse but thats not all

[Hexxus]

The post here:

1. https://www.badcaps.net/forum/showthread.php?t=27899
2. https://www.badcaps.net/forum/showth...light=LC320EM2

have similar boards and if not exact problems pretty close to mine

Here is a repair kit I found that I thought about getting: http://www.shopjimmy.com/emerson-a17...repair-kit.htm

I am trying to find out what is wrong with this power supply. It blew a fuse, put another one in and it blew as well so something deeper is the problem.

I only have a multimeter atm to work with, I will be getting a solder gun shortly.

Board info:

Ive test for a short in this picture:
all three legs short to each other. componet data sheet
2-3 = 0.3
1-2 = 0.4
1-3 = 0.4

In this picture, testing the green resister ohms i got .5:

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

Bump

[martino]

Re: Emerson LC320EM2 blown fuse but thats not all

remove that fet off the board,measure board at the 3 pins if short is now gone.
Good picture from bottom of board around that area? also one from top?



They list the components in that repair kit.I would for sure test all those.

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

remove that fet off the board,measure board at the 3 pins if short is now gone.
Good picture from bottom of board around that area? also one from top?



They list the components in that repair kit.I would for sure test all those.

Thanks for the reply. Solder station is on the way :P Will get back to you ASAP.

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

remove that fet off the board,measure board at the 3 pins if short is now gone.

Solder pads on board
pins 1-2 = 1 on meter no beep)
pins 1-3 = 320ish on meter no beep
pins 2-3 = 1500ish on meter no beep

testing the pads image, numbers but no beep. I am not sure what that means.

Fet pins
all pins short to each other (beep)


Images
Bottom 1
Bottom 2

Top

[martino]

Re: Emerson LC320EM2 blown fuse but thats not all

I would retest that with the meter on the 2000 ohm scale.If no reading,move it to the 20k ohm scale.
Right now meter is trying to read voltage drop on a diode.

Pictures without using flash,we need to be able to see the traces and components

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

I would retest that with the meter on the 2000 ohm scale.If no reading,move it to the 20k ohm scale.
Right now meter is trying to read voltage drop on a diode.

Retest the fet diode pins or the solder pads on the board? The last results here:

Solder pads on board
pins 1-2 = 1 on meter no beep)
pins 1-3 = 320ish on meter no beep
pins 2-3 = 1500ish on meter no beep

Are the pads on the board using the continuity/short setting as shown here: http://i.imgur.com/7it09aG.jpg



The FET diode pins on 2000 ohm and 20k ohm
1-2 = 0
2-3 = 0
1-3 = 0

on 200 ohm
1-2 = 0.9
2-3 = 0.4
1-3 = 0.7

fet solder pads on board
1-2 = 1180 @ 2000 ohm
2-3 = 1700 @ 2000 ohm
1-3 = 325 @ 2000 ohm

[martino]

Re: Emerson LC320EM2 blown fuse but thats not all

Fet is toast for sure. The 325 ohm between pin 1-3 on the board concerns me,but I cant see in those pictures what connected there. Can we get better pictures from top and bottom,that clearly show the traces around that dead fret etc?

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

Ill get a better camera and snap some pics in the morning.

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

I have been a little busy so I will get the pics asap. I received the repair parts I ordered, just waiting on the soldering station now.

I would like to test these parts before I go installing them. I am sure they are good as they should be new but you never know. I suppose I just look up the specs and test for it? I have never done that before.

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

While testing these I was getting strange and wildly changing readings. After messing with the multi-meter a couple times I would get a steady reading.
Pictures aren't of the actual part I received but look like them.
I am calling these parts by what they are listed on the website I ordered them from.

# - Part type - Model? - test results - setting - locations

2x Resistors 5W2.2RJ = 2.4 @ 200 ohms (Location R602, R11)

1x Resistors Colors (L to R): Brown Grey Silver Gold [ 0.18 ohms 5% tolerance?] = 0.4 @ 200 ohs (Location R608)


3x Diodes Unknown # = 660/870/890 Diode (Location D670, D610, D604)


1x Diode Unknown # = 340 Diode (Location D640)


1x Transistors D667 AC 9H2 = Don't know how to test or got strange results (Location Q601)


1x Transistors FQPF13N50C = Don't know how to test or got strange results (Location Q600)


1x Fuse F 4A 250V = Visual inspection not burnt/broken (Location F601)

[CapLeaker]

Re: Emerson LC320EM2 blown fuse but thats not all

I've repaired this before and others too. Look at this thread and check the components. Some components have to be unsoldered (because of the circuit they are in) in order to measure correctly.

https://www.badcaps.net/forum/showth...hlight=emerson

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

Some components have to be unsoldered (because of the circuit they are in) in order to measure correctly.[/url]

The components I list tested above are brand new.

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

Can we get better pictures from top and bottom,that clearly show the traces around that dead fret etc?

Maybe these are good?

[jetadm123]

Re: Emerson LC320EM2 blown fuse but thats not all

In the previous post, last picture. Is that blue capacitor next to the yellow transformer cracked in half?

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

In the previous post, last picture. Is that blue capacitor next to the yellow transformer cracked in half?

That is actually a beard hair of mine :P

[woodman45]

Re: Emerson LC320EM2 blown fuse but thats not all

Look at post #11 in this thread for service manual
https://www.badcaps.net/forum/showthread.php?t=49250

[CapLeaker]

Re: Emerson LC320EM2 blown fuse but thats not all

Look at post #11 in this thread for service manual
https://www.badcaps.net/forum/showthread.php?t=49250

I had forgotten about this one...

[Hexxus]

Re: Emerson LC320EM2 blown fuse but thats not all

Look at post #11 in this thread for service manual
https://www.badcaps.net/forum/showthread.php?t=49250

Thanks for posting this. I however have no idea what I am looking at with all that technical blueprint.

[woodman45]

Re: Emerson LC320EM2 blown fuse but thats not all

Thanks for posting this. I however have no idea what I am looking at with all that technical blueprint.

Most service manuals have a troubleshooting chart of symptoms and of what to test.plus it gives specs to different parts.i posted it to use for reference.

If you google how to test diodes and different components with a multi-meter there are a lot of vids out there that will help.

I've repaired a few of these boards and found that you're better off to replace every component that comes in the repair kit.

Good luck👍