ViewSonic VP201b

[PlainBill]

Re: ViewSonic VP201b

Hi guys,

I have one of that LCD VP201 that has the inverter fuses open. I replaced both with a 2A picofuse as explained in this post. Now the monitor powers and when it scans through the DVI-A, DVI-D, D-SUB it tells the message “No signal” and goes to sleep mode (amber light). It won't recognize any input into it. The amber light stays on and the monitor can be cycled on/off but I cannot get it to display anything in any of the inputs. I have verified in the controller board all the capacitors and they look ok and have good readings with a cap meter; also I have verified all the transistors and diodes for open or shorts and nothing bad.

Thanks all for any help or suggestion on this one,

mas

I had this happen on a close relative of that monitor TWICE. Once was user error - I didn't seat the DVI cable FIRMLY into the socket. The other case appeared to be the main logic board - it didn't like 1600 x 1200, but would work at lower resolutions.

PlainBill

[EGuevarae]

Re: ViewSonic VP201b

Hi guys,

I have one of that LCD VP201 that has the inverter fuses open. I replaced both with a 2A picofuse as explained in this post. Now the monitor powers and when it scans through the DVI-A, DVI-D, D-SUB it tells the message “No signal” and goes to sleep mode (amber light). It won't recognize any input into it. The amber light stays on and the monitor can be cycled on/off but I cannot get it to display anything in any of the inputs. I have verified in the controller board all the capacitors and they look ok and have good readings with a cap meter; also I have verified all the transistors and diodes for open or shorts and nothing bad.

Thanks all for any help or suggestion on this one,

mas

Welcome to the forums
Post a picture (clear one) of the signal/main/video board to see if I can get my hands on an exact one to try to help you.

[olenac]

Re: ViewSonic VP201b

Hi guys,

I have one of that LCD VP201 that has the inverter fuses open. I replaced both with a 2A picofuse as explained in this post. Now the monitor powers and when it scans through the DVI-A, DVI-D, D-SUB it tells the message “No signal” and goes to sleep mode (amber light). It won't recognize any input into it. The amber light stays on and the monitor can be cycled on/off but I cannot get it to display anything in any of the inputs. I have verified in the controller board all the capacitors and they look ok and have good readings with a cap meter; also I have verified all the transistors and diodes for open or shorts and nothing bad.

Thanks all for any help or suggestion on this one,

mas

[JohnBiggs]

Re: ViewSonic VP201b

Looks like it is a fuse thats bad. I'll order a few.

Thank You SOOO much

Now its time to rip apart the Dell 1700w again.

John

[EGuevarae]

Re: ViewSonic VP201b

So since it never comes on, I should keep focussing on the inverter even if the fuses look ok? No problem, but I will definately need help with that. I'll check the fuses tonight, if they are OK, I'll post pictures of the inverter board.

You guys are great!

Check the fuses to see if they are open.

Check also if voltage is reaching the inverter (from ground to a fuse you should get a V reading). If the backlight never lits, it is the inverter almost for sure.

[JohnBiggs]

Re: ViewSonic VP201b

It sounds like you're planning on 'shotgunning' it. This is a good approach if you are in a hurry or have money to throw away.

Your tests show the power supply and the A/D (control) board are both working. In my very limited experience if the backlight never comes on it is a problem with the inverter. If the backlight comes on, then goes off it could be either the inverter or the CCFLs.

PlainBill

So since it never comes on, I should keep focussing on the inverter even if the fuses look ok? No problem, but I will definately need help with that. I'll check the fuses tonight, if they are OK, I'll post pictures of the inverter board.

You guys are great!

[PlainBill]

Re: ViewSonic VP201b

Thank You very much. I'm going to check the fuses, if they are bad I'll replace them. If they are not, I'll buy CFLs and pray.

It sounds like you're planning on 'shotgunning' it. This is a good approach if you are in a hurry or have money to throw away.

Your tests show the power supply and the A/D (control) board are both working. In my very limited experience if the backlight never comes on it is a problem with the inverter. If the backlight comes on, then goes off it could be either the inverter or the CCFLs.

PlainBill

[JohnBiggs]

Re: ViewSonic VP201b

Before replacing tubes or fuses, check both fuses with a VOM. Exact replacement inverter fuses are available from Mouser, their part number 576-0429002.WRM. Or bridge it with a picofuse (2A fast blow).

ccfl surplus may be able to supply lamps.

PlainBill

Thank You very much. I'm going to check the fuses, if they are bad I'll replace them. If they are not, I'll buy CFLs and pray.

[JohnBiggs]

Re: ViewSonic VP201b

Welcome to Badcaps.Net
Have you tested the fuses on the inverter to see if they are open? The backlight turn on and then off or not at all?

I thought those were fuses at a glance, but I wasn't 100% sure so I didn't check them. I thought they could have been SM diodes. (At the time I was more concerned with checking the caps.)

Later I read more and found out they were fuses after I reassembled the monitor. Fortunately this one isn't as hard to get apart as my bad Dell w1700. LCDs hate me.

The monitor never lights. Just the green LED, then it goes amber if there isn't a source. I hooked up a source and using a maglight I could see there was color coming from the panel.

[PlainBill]

Re: ViewSonic VP201b

Ever find out where to get the inverter fuses or the new tubes?

I have the same monitor. Caps look ok. Power Supply puts out 17.88volts. reseated cables. I can see a hint of an image with a flash light.

Before replacing tubes or fuses, check both fuses with a VOM. Exact replacement inverter fuses are available from Mouser, their part number 576-0429002.WRM. Or bridge it with a picofuse (2A fast blow).

ccfl surplus may be able to supply lamps.

PlainBill

[EGuevarae]

Re: ViewSonic VP201b

Ever find out where to get the inverter fuses or the new tubes?

I have the same monitor. Caps look ok. Power Supply puts out 17.88volts. reseated cables. I can see a hint of an image with a flash light.

Welcome to Badcaps.Net
Have you tested the fuses on the inverter to see if they are open? The backlight turn on and then off or not at all?

[JohnBiggs]

Re: ViewSonic VP201b

Ever find out where to get the inverter fuses or the new tubes?

I have the same monitor. Caps look ok. Power Supply puts out 17.88volts. reseated cables. I can see a hint of an image with a flash light.

[PCBONEZ]

Re: ViewSonic VP201b

Like I said up in the second post the usual problem with Viewsonics is just bad caps.
-
First thing to do is get it apart and post some pics of the PCB's.
Sometimes different make/models use the same circuit boards.
There's enough folks in here now doing monitors someone might even recognize one of them.

[dantm]

Re: ViewSonic VP201b

Hi guys,

I'm very glad I found this thread. I'll be very grateful if any of you could help me troubleshoot a VP201b which died on me yesterday (or so it seems?).

I've had it for a few years and it's worked fine; over time it seemed to have developed some 'pixelation' issues (to explain it I'd say that if you were displaying a picture and it had a whole bunch of shades of a certain color it would display less shades and the image would not be smooth). I never thought anything of it since I was using it for general document/etc. work and not photo editing/etc.

A few months ago I bought a 2nd Viewsonic VP201b which is an older serial but in a better shape; it's practically like new (knock on wood :-).

I have the old one connected via DVI and the new one via D-SUB/VGA and they worked great for a few months.

Now, yesterday I powered both on and the old one (DVI) did not display anything; the LED is amber/yellow. I did every single combo of DVI/VGA cable in it; nothing. One time only I was able to get the VGA to display the image but it had a terrible *blue* hue to it -- here's a link to a picture I took:



Anyway since then it died and won't recognize any input into it. The amber light stays on and the monitor can be cycled on/off but I cannot get it to display anything.

Also when it scans through the DVI-A, DVI-D, D-SUB, the little icons have a blue tint as compared to my other monitor (where the text is black on a white-ish background).

Could you guys suggest any troubleshooting that I can do to see which part is bad? I'm ok with a few tools and electronics so please feel free to suggest anything.

Thanks!!!

[EGuevarae]

Re: ViewSonic VP201b

If you look at the pic (my inverter), you should notice that the inverter input is at the middle of a mirrored setup : same components on both sides of it.
I have a Totevision with a dead inverter (semi dead, in fact): Mirrored components, and just one side works. As just one side works, the whole inverter shuts down (even on a good working inverter, if you remove one of the lamps, it shuts off to prevent damage/overvoltage).
If one fuse is gone in your inverter, half of it would not work (no V input), which means that the inverter would be off.
It is more a theory based on previous experience than a technical explanation, but it is the only thing I can tell you now.

Your idea of the fuse protecting the board seems logic, but then again, if bad caps caused a surge/fault in the PSU output, that could have triggered the fuse. You can just replace the fuse and fire up the monitor.

[Noonespecial]

Re: ViewSonic VP201b

Sorry I may have not been too clear about that. Going by your picture (2) F1 or the one on the left of the image is dead. Using a volt meter I was not able to get any signal through it. Since it's a fuse, I suppose that means it's burned correct?

Now if thats the case, and it is indeed burned doesn't that mean there's an issue elsewhere and the fuse just saved the board?

I'll check the voltages on the other caps once I get home tonight.

But -- there is a green light on the front of the monitor. It does stay on, but there is nothing shown in the display. With the fuse being dead would this be the cause? Let me check the things you've mentioned and get back to you.

note: I really appreciate all the help you've given me. Thank you very much.
-N

[EGuevarae]

Re: ViewSonic VP201b

Well, sorry for the delay, I kept forgetting the Digicam at home. I ended up taking these pics with the cell phone. So I guess the quality isn't that good.

Here are things I've noticed:
If you look at pic #1, J2 [Edit: Looking back at it, it may be F1 not J2] (South of the Major Connection Cable) does not conduct electricity through it. In other words, the fuse you told me to look at (thank you btw) doesn't work. That fuse, I believe is dead, so I'll need to get a replacement for it. Might you know what kind of replacement it should be?

Other than that, @PCBONEZ, I'm not super savvy when it comes to this, I'm learning quick but still not savvy. I've enclosed pictures of the power supply from each direction. In all honestly it looks clean. I couldn't determine how to tell if there were "elite" caps though. What do they look like? Did you notice any? (See PIC 2-4)


Finally you mentioned to check the backlight lamps. I have gotten down to the last two pictures and I'm not sure whether I should go further. Are the back lights behind this? Please look at PIC 6 as well. The board there seems to be pressure sealed to the monitor. If I pop it out, will it go back in again? (Focus on the gold area)

It sounds pretty obvious, but... START FROM THE BEGINNING. First, see if you have voltage getting out from the PSU. The caps look good but they may be failing without visible indication. Look for something like "1000uf 35v" in one side, and in the other "Elite", "Teapo" or similar. The first is the capacitance and max V, and the later is the brand. If there is Elites, CapXons, or Teapos, better change them even if they are good.
You should have 18v output from the PSU. You can check the cables that go from PSU to Main board (two red, two black - you should get V reading from (-) black and (+) red).

If you do, you can check the fuses in the inverter. I marked their location.


And you know what?
Maybe is not your inverter.
You said it is dead. Dead means no turn on, no green led on the front. if you have a green led but no image, maybe it's the backlight or the lamps. If you do not have the green light (just as my own VP201b when I received it), it is a PSU cap problem.

And regarding the lamps, they can be removed/replaced. Just must be made very carefully. Hope the pics help.

[Noonespecial]

Re: ViewSonic VP201b

Well, sorry for the delay, I kept forgetting the Digicam at home. I ended up taking these pics with the cell phone. So I guess the quality isn't that good.

Here are things I've noticed:
If you look at pic #1, J2 [Edit: Looking back at it, it may be F1 not J2] (South of the Major Connection Cable) does not conduct electricity through it. In other words, the fuse you told me to look at (thank you btw) doesn't work. That fuse, I believe is dead, so I'll need to get a replacement for it. Might you know what kind of replacement it should be?

Other than that, @PCBONEZ, I'm not super savvy when it comes to this, I'm learning quick but still not savvy. I've enclosed pictures of the power supply from each direction. In all honestly it looks clean. I couldn't determine how to tell if there were "elite" caps though. What do they look like? Did you notice any? (See PIC 2-4)


Finally you mentioned to check the backlight lamps. I have gotten down to the last two pictures and I'm not sure whether I should go further. Are the back lights behind this? Please look at PIC 6 as well. The board there seems to be pressure sealed to the monitor. If I pop it out, will it go back in again? (Focus on the gold area)


PIC1


PIC[2-4]


[PIC 5-6]

[Noonespecial]

Re: ViewSonic VP201b

Oh you guys are awesome. I'm secretly sneaking onto this website to check on the post at work so I'll send you some pics and replies when I get home.

In advance, and as always, thanks for your replies and help

[EGuevarae]

Re: ViewSonic VP201b

Just found this on eBay. It is the same as the ones I can get. And they DO HAVE FUSES. Look at the pic, at both sides of the I/O connector.
I've seen both 201 and 211 with that inverter, and it is not like yours.