Asus Vh242 2 secs to black kind of

[silentscope]

I have an Asus Vh242. When I turn it on the first second it displays the Asus logo the backlight lights up then turns off, then it displays the HDMI channel and backlight comes back on and goes off again. If i plug it into my PC I can see the displayed letters by shining a flashlight on the screen, it just means that the backlight is off. I replaced one capacitor that kind of looked bulging and it didnt fix it. The other capacitors can be bad too but I cant be sure till I get my capacitor meter delivered.

Here are videos I took of the situation:
https://www.youtube.com/watch?v=mcQyFHBhyYQ
https://www.youtube.com/watch?v=JFFmw8EUEmM



http://i.imgur.com/F4JKT9a.jpg?1

[budm]

Re: Asus Vh242 2 secs to black kind of

You can see that the board got pretty hot, the SMD Power MOSFETs by the inverter transformers need to be checked.

[stj]

Re: Asus Vh242 2 secs to black kind of

that's some impressive heat marks - not in the realm of old philips gear, but still impressive.
i would recap that regardless, using high quality like pana FR all round because if they arent bad yet, they will be soon.

[silentscope]

Re: Asus Vh242 2 secs to black kind of

You can see that the board got pretty hot, the SMD Power MOSFETs by the inverter transformers need to be checked.

Thanks for the help, do you mean these two?

[budm]

Re: Asus Vh242 2 secs to black kind of

No, those are fuses. The SMD (Surface Mounted Device) are on the back side of the board.

[Joe Black]

Re: Asus Vh242 2 secs to black kind of

Could you post a pic of back of the board?

[budm]

Re: Asus Vh242 2 secs to black kind of

https://www.badcaps.net/forum/showthread.php?t=32833

See those 8-pin device on the bottom side of the board?
Your board really got hot, see the color of the board in the above link.

[silentscope]

Re: Asus Vh242 2 secs to black kind of



That was the first capacitor i replaced that didn't fix the problem. Can someone tell me how to read it? Is it suppose to be in the 900-1000 uF range since the capacitor is a 1000uF 25v spec?

and here is a picture of the bottom board

[budm]

Re: Asus Vh242 2 secs to black kind of

It has domed top and only has 336uF instead of 1000uF per your meter.
See those two 8-pin devices (below the big white line that goes across the board)? we need the P/N as printed on the top so we can get the pin out and then we can do the resistance test between S pins and the D pins.
Since the board got very hot, other caps should be replaced at the same, the heat probably dries out the caps.

[silentscope]

Re: Asus Vh242 2 secs to black kind of

It has domed top and only has 336uF instead of 1000uF per your meter.
See those two 8-pin devices (below the big white line that goes across the board)? we need the P/N as printed on the top so we can get the pin out and then we can do the resistance test between S pins and the D pins.
Since the board got very hot, other caps should be replaced at the same, the heat probably dries out the caps.

you mean this?


O wait you mean those two tiny black squares? If those are broken I don't think i can replace them, the soldering looks too tight with a regular soldering device.....

[stj]

Re: Asus Vh242 2 secs to black kind of

it's easy - dont panic over it.
like everything, there is an easy method once you know it.

[silentscope]

Re: Asus Vh242 2 secs to black kind of

Sorry for the lack of updates. I'm waiting for my delivery of capacitors to replace the current ones. One question is that i can find match uF rating but the voltage I can find are different. For example can I replace a 1000uF 16v capacitor with a 1000uF 25v one?

And do I need to worry about covering the new capacitor in this rubber casing that was on the old one ? Not sure where to find the casing size

[silentscope]

Re: Asus Vh242 2 secs to black kind of

[/QUOTE]

yea the this small one is rated at 22uf 50v the closest I could find was 22uf 400v will that do?

[Joe Black]

Re: Asus Vh242 2 secs to black kind of

Absolutely. Same capacity higher voltage is OK. (lower voltage is not good)

You can re-use rubber casing if you want

[silentscope]

Re: Asus Vh242 2 secs to black kind of

Ok good news is i think fixed the light, bad news is i forgot the layer order for the films... can anyone help with that

[silentscope]

Re: Asus Vh242 2 secs to black kind of

My monitor is working again. Thank you for everyone's advice and help. I greatly appreciate it. This place is full of amazing and helpful people. I had to replace all the capacitors on the burned looking area, excluding the biggest and smallest capacitor shown in the picture. They were all bad. This makes it the second monitor I have repaired myself. Total costs including the capacitor reader is approx. 40$.