ASUS VE247 Help

[aarynb1]

Hello everyone, I recently got an ASUS VE247 monitor for free because it was going to be thrown away. It would work fine for a while and then the image would freeze up, lines would appear and it would start turning white. I opened it up to have a look and I couldn't find anything wrong, and I left it apart for a while to see if it would mess up so maybe I could find the problem, but it never would. So I started to put it back together and after I did, it would not turn on at all, so I was hoping I could get some help here because it would be a nice monitor if I can get it working.
Thanks

Here are some pictures of the PCBs.

[aarynb1]

Re: ASUS VE247 Help

Can anybody help me out? I've looked at the pcbs and cant seem to find anything wrong. I can post more pictures if needed.

[newtothis]

Re: ASUS VE247 Help

Ok so it would turn on before messing with it but now won't?

Have you checked your connectors?

[aarynb1]

Re: ASUS VE247 Help

Yes, I have checked the connectors with a multimeter and there was no power.

[newtothis]

Re: ASUS VE247 Help

Just to make sure you tested it correctly... Set DMM to 20Vdc and put black probe to chassis (screwhole or something is good) and red into each of the pins on the connector that goes to the mainboard. Post results back like this

pin 1 - 0v
pin 2 - 5v
pin 3 - 0v
etc
etc

[aarynb1]

Re: ASUS VE247 Help

Ok, so I tested all the pins and got 0v on all of them. The components I circled in the image are pico fuses right? because I tested them and the ones I circled were bad.
Thanks for your help

[newtothis]

Re: ASUS VE247 Help

those are SMT caps... prefix is cXXX

Fuses will be FXX/16A or similar

Check your main fuse... the big one next to the large capacitor.

If ok check voltage at main cap, probe on each lead

[aarynb1]

Re: ASUS VE247 Help

Ok, the fuse was good, I got 381v while it was plugged in, and 97 while it was off.

[budm]

Re: ASUS VE247 Help

"381v while it was plugged in, and 97 while it was off" That cannot be right, when it is off, you should have around 160~170VDC right at the two legs of the main cap.

[aarynb1]

Re: ASUS VE247 Help

Oops... had the multimeter set to AC lol. I got 173v while it was on, and 40v while it was off.

[newtothis]

Re: ASUS VE247 Help

Those are way off, the chances of that cap being bad are slim!

Check your meter battery

[aarynb1]

Re: ASUS VE247 Help

I used a battery tester and it said it was bad, so I guess ill have to get a new one tomorrow and try it again. Is there anything else to check for right now?

[aarynb1]

Re: ASUS VE247 Help

Oops... had the multimeter set to AC lol. I got 173v while it was on, and 40v while it was off.

Did you see this post though, I retested it because I had it set to AC.

[newtothis]

Re: ASUS VE247 Help

Yes i looked at that post, As budm said it should read 160~170Vdc so 40Vdc is way too low, hence i asked about your meter battery

[aarynb1]

Re: ASUS VE247 Help

Ok well thanks for the help, ill get a new battery and test the cap again, and report back tomorrow.

[aarynb1]

Re: ASUS VE247 Help

Ok, I got a new battery for my meter today and checked again. I still got 170vdc while it was plugged in, and 44vdc while it was unplugged, is it possible the cap is bad?

[budm]

Re: ASUS VE247 Help

"44vdc while it was unplugged" that is because the cap was diacharging when the power is removed (not plugged into the outlet).
So reading at 170VDC when plugged in is OK.

[aarynb1]

Re: ASUS VE247 Help

What should I check next? I double checked and the logic board is still getting no power, all the components look good.

[aarynb1]

Re: ASUS VE247 Help

Sorry for the bump, but its been a while and no one has posted. Can anyone help me out? I can upload more pictures if needed.
Thanks.

[aarynb1]

Re: ASUS VE247 Help

How would you check the transformer I circled? I tried to check it and I got 170v on one side, and 0v on the other, but im not sure if I did it right.