Viewsonic VG2230 backlight

[szurlo]

First off, thanks for these great forums. I resurrected a dead VX922 a year or so ago with the information I found here.
Now for my current issue. I have a Viewsonic VG2230 that has started to occasionally have issues firing up the back light if the monitor has been in standby for several hours. The behavior is this: When the monitor comes out of standby and tries to light the back light, it will come on for MAYBE a second. Seems like probably more like half a second, and then go right back out. Power light stays lit. Cycling the power will usually bring the back light up on the first try but it does occasionally take 2 tries to get it to stay on. Once it does stay on, it flickers badly and the (I assume) transformer(s) on the inverter board make a very ragged whine. This all goes away in about 30 seconds and then the monitor works 100% normally until the next time it has been in stand by for several hours. Since this isn't always readily reproducible, and the monitor still works, I haven't torn it apart yet. Basically what I'm looking for is some opinions based on prior experiences, as to that the likely cause is so maybe I can order parts in advance. I assume this will come down to either something on the inverter board or the tube(s) themselves.

Thanks much!

EDIT: NOTE: This monitor has been in continuous service since 2007.

[jetadm123]

Re: Viewsonic VG2230 backlight

Your symptoms sound like bad caps. DO NOT try and preorder parts prior to opening and inspecting the power and logic boards, since viewsonic is known to use power supplies from different manufacturers. You may very well wind up ordering parts for the wrong board. Open it up and post some good focused photos of the power and logic boards.

[szurlo]

Re: Viewsonic VG2230 backlight

Thanks much for the response! I think I'm going to buy a new monitor anyway, since I'm thinking about building a new PC for my workshop so I'll just get that and use it in place of this VG2230 until I can repair it. That way I can tear it down and not be frantic to get it back in service Will post pics as soon as I have it apart.

[szurlo]

Re: Viewsonic VG2230 backlight

Here is a scan of the board. The red arrows point to bulging caps. The green arrows are caps that look OK. The silk screen is slightly out of focus so I annotated the image. The only one I don't know about is CE109. There are two caps (green and black) right together but only appears to be one label on the PCB. So should I just replace ALL the caps or just the bulging ones?
Thanks much,
Steve

[De3rcr]

Re: Viewsonic VG2230 backlight

It is recommended here to replace all the caps(looks like there are 9) except the big one(ce106). Most people recommend Panasonic FR, FM, FC as replacements. Make sure you get the specs of the caps( uf, voltage, height and diameter) when ordering.

[szurlo]

Re: Viewsonic VG2230 backlight

Thanks. Will do.

[retiredcaps]

Re: Viewsonic VG2230 backlight

So should I just replace ALL the caps or just the bulging ones?

Replace them all except the largest one which rarely, but not never, fails.

If the green colored caps are Samxon GF series (look for GF on the sleeve), they are a problematic series and fail prematurely.

[szurlo]

Re: Viewsonic VG2230 backlight

Replaced all the caps (except CE106) with Panasonic FM series. Back in business! Thanks folks!

Steve