Troubleshooting Viewsonic vx2235wm

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

I've uploaded some pictures so you can check my solder work. Let me know if you see anything questionable.

I've borrowed a multimeter, but, to be honest I don't really know what I'm doing here. I'd appreciate an explaination of the process of testing the voltages.

Should the board be connected to the rest of the monitor components when I test the voltages? What setting do I use on the multimeter? Which lead (black/red) do I touch where?

Sorry for being such a noob. I'm very interested in learning how to do this, and you're help is much appreciated. Thanks again.

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

Considering that the monitor at least powered on before but not after the recap, a few things come to mind...
First make sure you didn't create a solder bridge over anything. Also check if there are solder blobs shorting something.
The second thing that comes to mind - did you plug in all of the connectors properly and securely? Did you check for loose screws and other things that could possible short a nearby circuit.
Also, did you place the new caps in the right way, observing the polarity on the board and on the caps?
Last but not least, if you have a multimeter, check that the power supply is outputting the proper voltages. They should be labeled on one of the low-voltage connectors.

1) I did create a solder bridge at one point while connecting the new caps, but I corrected the problem before the monitor was tested. And I don't think there are any solder blobs, but I'll check again.

2)All connectors were securely connected and double checked. No screws that appear to be shorting anything.

3) I was VERY careful to observe polarity on the board. I created a schematic before removing the old caps, and followed it carefully. Even double checked everything before the test.

4) I'm going to borrow a multimeter and check the voltages next.

[jetadm123]

Re: Troubleshooting Viewsonic vx2235wm

In addition to momaka's comments, it might be helpful if you post some photos of your handiwork. Maybe someone will see something you missed. Post some good focused pics of the top and bottom of your board.

[momaka]

Re: Troubleshooting Viewsonic vx2235wm

Considering that the monitor at least powered on before but not after the recap, a few things come to mind...
First make sure you didn't create a solder bridge over anything. Also check if there are solder blobs shorting something.
The second thing that comes to mind - did you plug in all of the connectors properly and securely? Did you check for loose screws and other things that could possible short a nearby circuit.
Also, did you place the new caps in the right way, observing the polarity on the board and on the caps?
Last but not least, if you have a multimeter, check that the power supply is outputting the proper voltages. They should be labeled on one of the low-voltage connectors.

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

Hey guys. Well got my caps in and did the surgery. Think I did a decent job with the soldering, but I'm getting no power-on lights or picture. What should I test next? Thanks.

[999999999]

Re: Troubleshooting Viewsonic vx2235wm

Kostamojen, in addition to using a fine tip as retiredcaps mentioned, practice your soldering skills on some junk piece of electronics if in doubt.

While I've never tried doing it, in theory you could lay down some teflon tape, or any heat resistant material with a little hole that exposes the solder joint, but I suspect it would be more trouble than it's worth. If you have shaky hands, support your wrist with a book or something same height or a little taller than the PCB while soldering.

[retiredcaps]

Re: Troubleshooting Viewsonic vx2235wm

Looking at the caps you have to replace I don't think it is that bad. Just lean the solder tip away from other components. If you have a solder gun with a huge tip, that might be a problem, but a normal tip should give you plenty of space between components.

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

Hey guys, still waiting for my replacement caps to come in. But, I was inspecting the back of my circuit board and had a concern. With some of the cap soldering points, it looks like there is only a millimeter, or so, of space to the adjacent circuits on the board. I've never done precision soldering, so I was wondering if there is a good way to protect the adjacent circuits, while soldering the new caps. Any tips would be helpful. Thanks.

[jetadm123]

Re: Troubleshooting Viewsonic vx2235wm

I've been using the Digikey website to build my order, and I've run into a little snag.

I need 3x 1000uf 25v caps with max dimensions of 10mm(w) / 20mm(h) but can't find it in the FM or FC series on the Digikey website. Digikey carries Panasonic caps that fit these dimensions in the M, FR, or NHG series. Any problems with going with one of those series for this cap? Recommendations? Thanks again.

The Panasonic FR series will work fine.

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

I've been using the Digikey website to build my order, and I've run into a little snag.

I need 3x 1000uf 25v caps with max dimensions of 10mm(w) / 20mm(h) but can't find it in the FM or FC series on the Digikey website. Digikey carries Panasonic caps that fit these dimensions in the M, FR, or NHG series. Any problems with going with one of those series for this cap? Recommendations? Thanks again.

[seanc]

Re: Troubleshooting Viewsonic vx2235wm

I've just never seen it there before. I've seen the silkscreen, but no port.

[PlainBill]

Re: Troubleshooting Viewsonic vx2235wm

That's interesting - the audio port is on the power supply board.

That is common. After all, we aren't dealing with a Marantz amplifier and JBL acoustic suspension speakers here.

PlainBill

[seanc]

Re: Troubleshooting Viewsonic vx2235wm

That's interesting - the audio port is on the power supply board.

[PlainBill]

Re: Troubleshooting Viewsonic vx2235wm

WEll you guys were right. I managed to get the case open and discovered a leaking cap and several bulging caps (pictured below). They are all CapXon KF series, with the exception of the one I've labeled "A", which appears to be a GL series. Since this is my first time doing a cap replacement, any suggestions on a replacement brand/series for these? Does the series matter? Any help would be appreciated.

Personally, I prefer Panasonic FM or FC series caps. Other name brands have equally good series. The thread 'Which caps should I buy' in the FAQ will give you information on those.

If you are in the US, Digi-Key is a good vendor, particularly for a small order like this. A full set of caps will cost about $10.00, including shipping. If you live in another country, another thread in the FAQ might help you - 'Where can I buy Caps?"

Instructions on selecting caps are in this post. Pay particular attention to dimensions. It's inconvenient if you can't get the cover on because a cap is too high. And do replace all the electrolytic caps (except the 100 uF, 450 volt one). Some of the smaller ones can fail without any external sign.

PlainBill

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

WEll you guys were right. I managed to get the case open and discovered a leaking cap and several bulging caps (pictured below). They are all CapXon KF series, with the exception of the one I've labeled "A", which appears to be a GL series. Since this is my first time doing a cap replacement, any suggestions on a replacement brand/series for these? Does the series matter? Any help would be appreciated.

[retiredcaps]

Re: Troubleshooting Viewsonic vx2235wm

Like seanc says above, this sounds like bad caps. As the caps warm up, their ESR (ohms) drops and allows the lcd to come on.

[seanc]

Re: Troubleshooting Viewsonic vx2235wm

Bad caps in the power supply.
Replace ALL them except for the large filter cap (unless it shows signs of distress) and it'll be fine - but stop using it before you destroy something else.

[Kostamojen]

I'm searching for a fix for a Viewsonic vx2235wm monitor and found this site almost immediately. Over the past weekend, the power at my work went out and my boss' monitor stopped working. I'll give the symptoms that I've noticed and hope to get tips on further troubleshooting or repairs. All my testing was done using the VGA connector, not DVI.

When you power on the monitor, the blue light flickers for 1-2 seconds and then goes dark. If the monitor is left powered on but NOT connected to the PC video, the message for "No Video Signal" will appear after 10-15 minutes and the power light will come on in the orange power-save mode.

One time last night I powered the monitor on (same blue light flicker for a couple seconds) and I left the PC Video connected. After about 20-30 minutes the PC video suddenly appeared on the monitor. I used the monitor for several hours with no problems. At one point I powered it off and back on, it came right back up. However, I turned it off for the night and It exhibited the same flickering blue light then dark symptoms in the morning. I haven't had time for further testing yet.

Any ideas on what the problem is or further tests I should do? If I can get it working, I get to keep the monitor . Thanks.