Troubleshooting Viewsonic vx2235wm

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

It's a pigtail fuse, I'm guessing somewhere in the 2A - 4A range. You may be able to read teh current rating on the end caps. Some monitors us a picofuse in this application, others use a surface mount fuse. A fuse and fuseholder from Radio Shack would even work.

Before replacing the fuses, check the inverter drivers to make sure they aren't shorted. If nobody jumps in with directions, I'll do it tomorrow. I can't keep my eyes open.

PlainBill

Hey Bill, got those directions on checking the inverter drivers? Much appreciated.

[PlainBill]

Re: Troubleshooting Viewsonic vx2235wm

Hey Bill, got those directions on checking the inverter drivers? Much appreciated.

OK, here we go. These tests will be done with power off.

The inverter drivers are two 8 pin ICs next to the inverter transformers. There is space for two more next to them. The two empty spots appear to be U200 and U201. I THINK the drivers are U202 and U203.

If you look at the drivers you will notice a dimple next to one pin. That is pin 1. The other pins along that side are 2, 3, and 4. Pins 5-8 are on the other side. Pin 5 is opposite pin 4, pin 6 opposite pin 3, etc.

1. Set your VOM to the X10 range and adjust the zero with the leads shorted.

2. Put the black lead on pin 1 of the first IC. Measure the resistance to pin 2, pin 3, pin 4, and pin 5. Note any reading that is below 10 ohms.

3. Put the black lead on pin 2 of the first IC. Measure the resistance to pin 3, pin 4, and pin 5. Note any reading that is below 10 ohms.

4. Put the black lead on pin 3 of the first IC. Measure the resistance to pin 4, and pin 5. Note any reading that is below 10 ohm

5. Put the black lead on pin 4 of the first IC. Measure the resistance to pin 5. Note any reading that is below 10 ohm

Now repeat these steps for the other IC.

PlainBill

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

ICs look good. No measurements under 20 ohms. Anything else I should do before trying to find a replacement for the glass fuse?

[Th3_uN1Qu3]

Re: Troubleshooting Viewsonic vx2235wm

Nothing else for now.

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

Glass fuse is PGU manufact. and labeled F3.15A 250V. Radio Shack for replacement? Or should I look somewhere else? Anything special I should be aware of?

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

Radio Shack is coming up short. They have fuses with the amps and voltage. But they don't have a bracket that will work with the board. Recommendations?

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

Time for a little education on fuses:

Found a fuse on Digikey that might work. http://search.digikey.com/scripts/Dk...&name=F3298-ND

Looks like the same amp and voltage rating. Can't tell if its glass or if that even matters. Can anyone tell me if that fuse is viable for this application?

Thanks again.

[Th3_uN1Qu3]

Re: Troubleshooting Viewsonic vx2235wm

F3.15A 250v = fast blow, 3.15 amps, 250 volts. I'm sure you can find that at Radio Shack. If you don't have a bracket for it, rip one out of an old something. What you have there on Digikey is a slow blow, which will take some time to open, giving more chance of blown transistors.

If you can find a fast blow then you're alright... but unless you have a bigger order to make, just a couple fuses are going to be a waste. Buy from your local shack and get creative about those leads. Hint: You CAN use a soldering iron on a fuse.

[momaka]

Re: Troubleshooting Viewsonic vx2235wm

Buy from your local shack and get creative about those leads. Hint: You CAN use a soldering iron on a fuse.

+1
Or you can make your own fuse holder out of paper clips. No, I'm not kidding!

[jetadm123]

Re: Troubleshooting Viewsonic vx2235wm

3.15 A fuses are used quite often in computer power supplies. If you have an old power supply lying around, perhaps you could "liberate" the fuse from it.


As for a fuse holder for the fuse you already have, maybe you could use the Radio Shack one below:

http://www.radioshack.com/product/in...ductId=2062257

You could try glueing it down with silicon adhesive. Just make sure it's metal tabs don't come in contact with other components.

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

Managed to find a fast blow fuse with the proper amperage and voltage at Frys. They didn't have a pigtail fuse, so I got a little creative with the soldering iron and some discarded leads from the cap replacement. I've attached a photo of the custom fuse. Installed everything and the monitor fired up like a beauty! Thank you to everyone who contributed to this thread. You were all a great help. And I got a 22" widescreen monitor for $20 in parts. I think I'm hooked!

[PlainBill]

Re: Troubleshooting Viewsonic vx2235wm

Managed to find a fast blow fuse with the proper amperage and voltage at Frys. They didn't have a pigtail fuse, so I got a little creative with the soldering iron and some discarded leads from the cap replacement. I've attached a photo of the custom fuse. Installed everything and the monitor fired up like a beauty! Thank you to everyone who contributed to this thread. You were all a great help. And I got a 22" widescreen monitor for $20 in parts. I think I'm hooked!

Well done. And your's is a common reaction. Whether it's fixing your own, or one someone else discarded, it's a good feeling.

PlainBill

[Th3_uN1Qu3]

Re: Troubleshooting Viewsonic vx2235wm

Good job. Enjoy your new monitor. And please post your location in your profile, so it's easier for us to suggest a part supplier when you next need it.

[alexanna]

Re: Troubleshooting Viewsonic vx2235wm

Kostamojen it's fun isn't it!


Th3 Un1Qu3, Just a little off topic
But do you guys have a July 4th over there
Al.

[PlainBill]

Re: Troubleshooting Viewsonic vx2235wm

Kostamojen it's fun isn't it!


Th3 Un1Qu3, Just a little off topic
But do you guys have a July 4th over there
Al.

Of course they do. It comes between Iluie (July) 3rd and Iluie (July) 5th.

PlainBill

[Th3_uN1Qu3]

Re: Troubleshooting Viewsonic vx2235wm

Of course they do. It comes between Iluie (July) 3rd and Iluie (July) 5th.

PlainBill

It's Iulie. Nope, we ain't got 4th of July here, only New Year. We did "import" Halloween tho.

[Kostamojen]

Re: Troubleshooting Viewsonic vx2235wm

Hey guys, the monitor I repaired seems to be showing a new symptom. I'll try to explain as best I can.

The monitor runs consistantly good while connected via VGA (analog). However, when running on the DVI (digital) connection, the screen occassionally goes black for 2-3 seconds, and then comes back on. Sometimes when it comes back on, there are red pixels across portions of the screen, and the monitor will reset itself again after a few seconds.

I've only noticed this issue while playing games on the computer, but, it might not be limited to only then. I'd really love to run this monitor off the DVI connection, cause the picture is even better. Any ideas how to resolve this issue?

Thanks in advance.

[jetadm123]

Re: Troubleshooting Viewsonic vx2235wm

Hey guys, the monitor I repaired seems to be showing a new symptom. I'll try to explain as best I can.

The monitor runs consistantly good while connected via VGA (analog). However, when running on the DVI (digital) connection, the screen occassionally goes black for 2-3 seconds, and then comes back on. Sometimes when it comes back on, there are red pixels across portions of the screen, and the monitor will reset itself again after a few seconds.

I've only noticed this issue while playing games on the computer, but, it might not be limited to only then. I'd really love to run this monitor off the DVI connection, cause the picture is even better. Any ideas how to resolve this issue?

Thanks in advance.

Have you verified that the DVI output of your computer's video card is not the problem? Also, have you checked to make sure it's not the DVI video cable connecting your monitor and computer?