Emerson\Funai alc320emxf will not power on

[willy3486]

I have a TV that is labeled Emerson on the front but Funai on the model label. It says it is alc320emxf. The issue it is having is that it has now lights or power when turning on. I checked the switch and I get contact when pressed. I checked out what I think is the main power board and on the 2 wire plug it has around 160 volts constant. That plug connects to what I think is the inverter board. I also checked the main diodes and fuse, they checked fine with a ohmmeter from what I can tell. I did find two sb390 Schottky barrier diodes at d641 and d642 that ohm out to .1 ohm. I don't remember the difference between testing Schottky and standard diodes if any. They are still in the circuit as of now.

With that said I am leaning towards these Schottkys but its been so long since I had dealings with them. I don't have any of these diodes here or at home or I would try them. I can get them but I have to go through and get purchase orders and that is a pain on small items like this. Would it be a chance of a different board being bad? Also due to age would it be better to just buy a replacement?

Thanks in advance for help.

[budm]

Re: Emerson\Funai alc320emxf will not power on

You need to test them off the board first just to be sure. 0.1 Ohm is not right, and your meter probes really < 0.1 Ohm resistance? What Ohm scale are you on?
We also need to see the pictures so we can see what we are dealing with.

[willy3486]

Re: Emerson\Funai alc320emxf will not power on

The diode itself is .1 ohm, With the leads and diode it has a total of .4 ohms. I took off the .3 ohm of the leads. That was reading at the lowest ohm scale on a digital meter. I got the time to take one lead of each diode off the board and measure it. One of the sb390 diodes measured similar to other diodes, higher one way than the other. The other sb390 diode,part d641 with one lead out of the circuit checked out at .1 ohm both ways. So I think this is the culprit. What was throwing me off was that they are installed in parallel. So in circuit both tested bad. But once I got them out I could tell one was good and the other was bad.


From a search the board looks to be aPhilips A91F2MPWS001 (BA94F0F01024_A, BA94F0F01022_A) Main CBA. I may look around at home to see if I can find one there. I have lots more parts at home than here at work.

[willy3486]

Re: Emerson\Funai alc320emxf will not power on

I got it going! I have a storage closet for junk parts. I work mostly on computers and printers so I looked in there thinking a power supply might have one. I found a xerox printer board that had one. I replaced the bad one with one from the xerox power supply. It worked. I am bench testing it but I think it will be fine as long as something else didn't cause the sb390 to go out. Thanks for the help.

[nomoresonys]

Re: Emerson\Funai alc320emxf will not power on

Nice job, looks like you solved it.

[CapLeaker]

Re: Emerson\Funai alc320emxf will not power on

you were lucky. Usually there is way more than just one diode bad.