Question about ViewSonic A90

1 Answer

Fuse blows. I have replaced the blown fuse, but the new one pops as well. Any suggestions? Where can I obtain a set of schematics? Rick

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • ViewSonic Master
  • 12,061 Answers
Re: Fuse blows.

OK it would appear that you have a failed "Chopper" transistor(s) in you SMPSU. I would try Googling for the "Service manual" you most probably can buy one online. Good Luck.

Posted on Jul 31, 2007

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

1 Answer

I herard a pop and now it won't turn on wanna find out if it under warranty

The pop you heard was the Bus Fuse blowing. If you can do some simply handy work it will be much easier, simplier, and cheaper to change the fuse you self. It requires taking off the back, locating the fuse ( probably close to where the power cord comes in ) and removing the old from the holder and putting in the new.

Hope this helps.

Jun 23, 2010 | Soyo 19" LCD Flat Panel Monitor

2 Answers

Fuse blown on power supply board, replaced fuse blows straight away,

It is possible that it is shorting somewhere, try checking wires and/or any contact point where it can ground/earth itself

Jun 26, 2010 | Hanns.G Corporation HX191DP LCD Monitor

1 Answer

Blown fuse on a ilpi-009 power supply

hi, i don't know the exact power board you speak of, most fuses for power supply protect ac inboard power, and backlights. if backlight inverters touch ground or ground out, this will blow fuse. otherwise, the fused circuit is used for main inboard power going to primary capacitor. take an automotive fuse holder and solder test leads long enough to work with, install 4 amp blade fuse and jumper/solder the circuit to the fuse on the board and power on the monitor. if all goes well, probably just power surge or outlet grounded. if blows fuse, check to board for obvious burns or blown capacitors. if not there, unplug backlights and power on, if still blows, check to make sure no direct conact with board and back of screen. just be thorough about looking carefully for shorts if there is one. and don't forget to replace the factory fuse on the board with the correct one after you finish repairing, don't leave that automotive fuse in. good luck.

May 10, 2010 | Emprex LM2201 22" LCD Monitor

1 Answer

Same thing.


If you have the 2 blown capacitors on the power board then most likely yo also have blown MOSFETs and a blown fuse. The MOSFETS and fuse blow when the capacitors short out when they blow. We sell a kit with the capacitors, MOSFETs and fuse with instructions for $10.00 plus shipping. Let me know if you need a repair kit.

Corporate Computer

Jun 25, 2009 | Westinghouse 22" Widescreen LCD Flat Panel...

2 Answers

Viewsonic VP201b, power light but no menu or picture


The fuse on the inverter is very small usually small that a grain of rice. It will be labeled F something such as F101 F205 etc. The other thing to look for is blown capacitors, they are anywhere from 1/4 to 1/2 inch in diameter and 1/2 to 1 inch in height. When they blown the top that is normally fat will either have a domed top or the top will be fully popped open. If you see anything that looks like that then they will need to be replaced before you replace the fuse or it will just blow again. The values on the capacitors are marked on the plastic sleeve that is around them. You may be able get them from Radio Shack but most likely you will have to order them to get the right values. If you have additional questions just email me. I am in the process of posting some pictures of bad capacitors on my web site at

Corporate Computer
Over 21 years of computer and printer support and repair

Jun 19, 2009 | ViewSonic VP201s 20.1" LCD Monitor

1 Answer

Plug it in with no input connected,press the

I suggest you don't.
There are no user friendly replaceable parts in there.
There May be an inline fuse in the AC circuit, but it's probably a circuit breaker. (Closest thing to a user friendly part, that you'll find)

I suggest you take it to a 'Mom & Pop' computer shop, and see if they will check for a blown fuse inside. The small qualified shops like these, have real computer techs, and not 'Geeks are Us'.
Plus they're cheaper.

If it isn't something simple like a blown fuse, or bad circuit breaker, it's probably the power board.
(Usually the front cover comes off, from loosening it on the backside)

The reasoning for dissuading you from opening the monitor, is that there are Electrolytic Capacitors inside.
They are designed to hold a charge for weeks, sometimes months.
Should you touch the terminals making a circuit, or touch the circuit they're in, and complete a circuit, they could release their charge to you!

This can easily result in a bad shock, or 'Put X's in your eyes'.
(The Electrocution warning on the outside is For Real!)

Apr 22, 2009 | Acer AL2223W 22" LCD Monitor

3 Answers

HP LCD Monitor w1907 Blowing fuse - no display

1. Visual inspection of the board, wires, etc. for short (expect you have already done this)
2. Start at the source. Need a meter to test voltage coming into the system (is it really 110VAC?)
3. Then the obvious, which is not so obvious or you would have fixed it by now. Need a meter to test components. Test switch. Maybe the power swtich is shorted!? Test all other components one at a time. Including all the wires. Do any of them feel stiff or look like the insulation might have melted a bit? Might need to remove wires to isolate components to test.
4. Since the power switch is not part of the problem then it is before the switch. When it was working, did anything run while the power was off? yellow LED? fan? Components like power diodes, bridges and rectifiers are typically blown by now also.
5. A filter capacitor, usually large, when shorted internally, can be the problem. Only test for short. Must remove one lead, watch polarity.
6. You can only blow so many fuses before the real problem, which the fuse is protecting, will appear...usually a disasterous end. I blew up a power supply to a washing machine after the third fuse. It fried the whole board with a very loud pop, bright flash and fragments of shrapnel flying everywhere. Please be careful!

Troubleshooters rules:
1. When you can't find the problem you are looking in the wrong place. Look somewhere else. Suspect everything, even the smallest detail is often the real problem. Like, what have you ruled out? Did you already assume the switch was good, the wire from the wall was good, the outlet was good, the power was good?
2. When you don't know what else to do, do something. Deliberately break something to see what will happen. (This is not a rule that I would use in this case but might serve you well in troubleshooting other problems in the future.)

Nov 28, 2008 | HP Pavilion F1703 17" LCD Monitor

2 Answers

Fuse blown repeatedly on CB553H-KL


Re your post/description on an LG CB553H-KL fuse blowing, this is indicative of an over current (>5Amps) flowing through the AC mains supply. If you are comfortable doing component level repair and familiar with electronic parts/circuitry, continuity tester and a soldering iron, please do passive (off-board) test of the following components:

D900 - bridge diode;
C908 (150uF/400V) - filter/power capacitor;
Q901 - regulator.

If Q 901 is shorted, pls likewise check ZD901, D910, R902 & 915.

Just to be sure/safe, check also:
C901, 902 & 904;
TH 901 & 902;

Though unlikely, you may want to check also:
Q706 - Horizontal out transistor (attached to the aluminum wall acting as heatsink;
FBT - Flyback transformer.

Other than the component aforementioned, no other parts would cause enough current flow to blow the fuse. But of course, anything can still be wrong

Hope this be of some help. Pls post back how things turned out or should you need additional information.

Good luck and kind regards.

Nov 16, 2007 | Compaq FS 7550 17" CRT Monitor

2 Answers

No display

I have repaired 3 Viewsonic VP211b monitors.
The power light comes on but there is in picture. In all three cases it was the same problem. It was a blown fuse on the inverter board.
1. The monitor must be opened: The black plastic back is pried off carefully. It is easy to damage or crack. This will expose the electronics.
2. Remove the metal covers: The power main board has a metal cover that is secured with 4 screws. When that cover is removed, you can then remove the cover over the inverter.
3. Remove the inverter: The inverter is held with 1 screw. There are a total of 6 pairs of wires to the fluorescent lights (3 on each side) that must be disconnected from the inverter and a there is a power and control cable to the main board that must be disconnected. The inverter should now be free.
4. Test the fuses: On the inverter there are two tiny surfaced mounted fuses, labeled F1 and F2. They are on either side of the power cable CN1. Either one can be blown. Test them both with an Ohmmeter.
These fuses are 1.5 mm long, 1.0 mm wide and 0.5 mm high (Case Style 1206). They have the letters FN printed on them. The N is for 2 Amps and the F is for Very Fast Blow.
I replaced them with the same fuse, except Fast Blow rather than Very Fast Blow. The replacement fuse has just the letter N. The FN was not available at the time and I felt the N would be close enough. The fuses were made by LittleFuse. They were purchased from Newark Electronics. Part number 64R8010.
Prior to acquiring the surface mount caps, I tested the inverter board by soldering a regular fuse across the blown fuse and putting the inverter back into the monitor. The monitor came back to life. Normally when there is a fuse blows, it is because there is a short someplace down stream. How ever the new fuses have held. Therefor I am assuming it was just faulty fuses.
With the new surface mounted fuses, the repaired boards were placed into monitors and they all worked.9486ec61-dd3d-4a22-bbc3-82b55a458b09.jpg00ad0ac3-9cf1-4fff-83ed-90d93e6a0e0a.jpg40cff7a9-f7c7-4904-aac3-eb656a117911.jpg0ee0c7e1-1e8a-4b07-936c-83557d5ddd2b.jpg3ccdb800-f497-41ee-b268-cad6a2330191.jpg4d8ec0f3-f0e3-4e06-bc47-791b2996f04b.jpg

Jun 02, 2007 | ViewSonic VP211b 21.3" LCD Monitor

1 Answer

A90 Fuse

Try JAYCAR take the fuse into the store. You should get something to do the job. Be aware that the fuse may have blown for a reason and may be an indication of something more serious.

Aug 10, 2006 | ViewSonic A90

Not finding what you are looking for?
ViewSonic A90 Logo

Related Topics:

53 people viewed this question

Ask a Question

Usually answered in minutes!

Top ViewSonic Computer Monitors Experts


Level 3 Expert

18258 Answers

Brian Sullivan
Brian Sullivan

Level 3 Expert

27725 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17129 Answers

Are you a ViewSonic Computer Monitor Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides