Viewsonic VP201s

[Wrog]

Hi all, excellent forum and resource here, thanks to everyone who shares their knowledge and experience! I've had a great time reading through the many threads and learned more than I ever expected. Here's the situation:

Viewsonic VP201s powers up to a black screen (green power LED is on).

Cracked open the monitor and found the following:

1. Power supply area seems fine, Nichicon caps. None that I can see are bulging or leaking. Did not test output voltage levels of the power supply (18V).

2. Tested the inverter fuses, and found F1 to be blown (F2 was OK). Local shops don't carry 63V/2A surface mount fuses, but did have a 2A pico fuse that I can solder in its place. The caps on the inverter board are Rubycon and physically appear to be fine.

3. In the mainboard area, there is a lot of what looks like some sort of rust-colored substance (maybe corrosion?). I've highlighted in red areas that seem to be the worst, like around the screws and IC954. I haven't taken the board off to check the bottom to see what that looks like yet to find the source.

I'll post back later with more details, but if anyone has suggestions on what the substance could be in the picture, I'm interested in finding out what caused F1 to blow in the first place to prevent it from occurring again (even if replacing the fuse ends up working). Thanks for any input.

[Wrog]

Re: Viewsonic VP201s

Update: The bottom of the mainboard is more of the same rust-colored "corrosion" that can be scraped away by fingernail. It's particularly concentrated around the connector to the inverter and also by the DVI connector (marked with red rectangle). Guidance on the direction to go to troubleshoot this would be great, unless I should just replace the fuse and fire it up! Looking at IC954 (first picture above), I'm going to guess this is a big problem and it likely needs to be replaced (it's virtually covered in the rusty stuff).

[PlainBill]

Re: Viewsonic VP201s

Update: The bottom of the mainboard is more of the same rust-colored "corrosion" that can be scraped away by fingernail. It's particularly concentrated around the connector to the inverter and also by the DVI connector (marked with red rectangle). Guidance on the direction to go to troubleshoot this would be great, unless I should just replace the fuse and fire it up! Looking at IC954 (first picture above), I'm going to guess this is a big problem and it likely needs to be replaced (it's virtually covered in the rusty stuff).

The inverter fuse blowing for no obvious reason is fairly common on these monitors. I used a variable power supply to apply power slowly before replacing the fuse. Alternate approach is to check for shorted transistors before applying power.

PlainBill

[EGuevarae]

Re: Viewsonic VP201s

The inverter fuse blowing for no obvious reason is fairly common on these monitors....

Also clean the corrosion-like brown thing as it can cause problems.
Resolder the inverter's transformer and all suspected points on the inverter.

[ecking767]

Re: Viewsonic VP201s

Clean your board with alcohol, an old toothbrush and a rag.Soak the rag with alcohol and place the rag over the board and then gently brush on top of the rag clean the board where you have soak the alcohol. repeat if necessary. your board will be nice and clean looking !!!

[Wrog]

Re: Viewsonic VP201s

Thanks everyone for your input, looks like I have some work to do. A friend of mine gave me a Gateway FPD2185W to look at so I've got that cracked open too. I'll likely have questions about that one I'm sure.

[Wrog]

Re: Viewsonic VP201s

Chalk up another success story! Replaced surface mount fuse F1 on the inverter and it fired right up. The replacement fuse part I ended up using was Digikey P/N F1457CT-ND, which is a Littelfuse 0466002.NR 63V 2A Fast Acting 1206. The toughest part was getting the darn thing open (that, and waiting 4 days for the parts to arrive!)

Thanks again everyone for your help. Now on to the Gateway FPD2185W...

[Moving Target]

Re: Viewsonic VP201s

This is my first post on this forum and I would like to compliment the administrators and members on the quality of the posts and information residing here. I have a similar problem to that mentioned by Wrog. I have twin Viewsonic VP201s monitors that have worked well for over five years. One started "timing out" after a while (black screen and no power on LED light). If I shut it off and waited a minute or two it would turn back on and run for another hour or two. I started relying on the other monitor until it just blacked off with the LED still lit. I have taken both units apart and managed to make one work by switching the inverter board from the "intermittent" monitor to the one that shut off but retained the LED power light. Given the info in this and other threads on the site, it is likely that one or both of the inverter board fuses are bad. I would rather replace one or two fuses than spend $100 for a new board for a 6 year old monitor. Does anyone have pictures that identify the inverter board fuses? Is the part number that Wrog specified the one to use and where might I order them? If and when I get the inverter board fixed can someone give me a possible diagnosis for the intermittent power off problem? The capacitors on the board all look good and I'm not sure where to start. All advice and counsel would be appreciated! Thanks, Moving Target

[selldoor]

Re: Viewsonic VP201s

Hi - The fuses will be marked F1 F2 on the inverter board, If you post a picture of your board I can mark them on it for you.
Do you have a multimeter?

[Rtech]

Re: Viewsonic VP201s

The intermittent Power off, could either be Power Supply OR main Board,so you will need to identify which one is Faulty, as you have 2 of the same type,then by switching over the working inverter board,and then substituting the Power Supply and Logic in turn you can identify the fault down to the correct board,and then move on from there.

[budm]

Re: Viewsonic VP201s

Is this the board you have? The Green PICO Fuse.

http://s807.photobucket.com/albums/y...onic%20VP201B/

[Moving Target]

Re: Viewsonic VP201s

Gentlemen - Thanks for the quick replies. I'll need to get the bad inverter board back from an acquaintance that was looking it over so I can take some photos, but it appears to be the same board that is seen in Budm's pictures. Is the fuse that is the possible problem the green component on the left side of the board?

Budm - Great shots of the case dis-assembly and the components. I figured out how to open the monitors with no damage myself, but if I had seen your pictures they would have spared me a lot of apprehension.

selldoor - I do have an inexpensive multimeter. Will that work?

Rtech - I switched the inverter board from the unit that was having intermittent power problems to the unit with the bad board. Now that monitor is up and running and is not shutting down. It appears that the intermittent problem is not on the inverter board as you imagined. I'll have to do some more testing with the second monitor, but how difficult is it to diagnose a problem with the power supply or main board and fix it? Will the expense mean it would be wiser to retire it?

Thanks again for your shared experience.

[selldoor]

Re: Viewsonic VP201s

An inexpensive meter will do fine as long as it measures volts and ohms and is
fairly accurate.
Yes its the green torpedo where it says F1.

I think what Rtech means is that even when you change the fuse, if the set made up of possibly faulty boards does not work, you will still not know if the fault is Inverter Board or the power board. You can reduce the amount of testing by trying the inverter board back in the monitor that now works, as if it does it may the power board that is faulty. (or main board)
Similarly if you have not tried already you could try the Power board and indeed
the main board and so determine which board or boards are faulty.

We can then advise on some quick easy tests to determine if its an easy fix,
so its too early now to retire any board.

[pepinlady06]

Re: Viewsonic VP201s

I have a question about the viewsonic vp201s inverter board can someone help me plz

[budm]

Re: Viewsonic VP201s

What kind of questions? Which version of VP201S do you have? Pictures of the boards, etc?

[pepinlady06]

Re: Viewsonic VP201s

don't know how to post a picture of it on the back it says delta 2994721100 dac - 18B013 and there is no green pico fuse on it

[budm]

Re: Viewsonic VP201s

So, what are you looking for? What is the question? Does it have label on the board like F1?
Here is how to post the pictures:
https://www.badcaps.net/forum/showthread.php?t=1868

[pepinlady06]

Re: Viewsonic VP201s

well it powers on but no picture and there is a small brown spot on the back of the inverter board don't if that's the problem should i replace this one?

[budm]

Re: Viewsonic VP201s

You need to find out if you do have power supply voltage feeding the inverter board or not by measuring the DC voltage on the both ends of the fuse using the chassis as the Ground ref point, also need to find out if the inverter board also getting the BL_ON (INV_ON) signal or not.

[pepinlady06]

Re: Viewsonic VP201s

here is a picture don't know good it is