Please Help Viewsonic VX2235wm NO Light

[johanlien]

hello all,

ihave a problem with my viewsonic LCD vx2235wm 22"

It no light I can see the image if i put a flashlight on the screen

this a board picture

Please Help me

[retiredcaps]

Re: Please Help Viewsonic VX2235wm NO Light

It no light I can see the image if i put a flashlight on the screen

1) Check the fuse (left of the barcode) with a multimeter. It should read less than 1.0 ohms.

2) Check the two ICs just below the two yellow inverter transformers. Look at the part number, find its datasheet, and measure the resistance between S-G, G-D, S-D. Any reading under 30 ohms suggests it is shorted.

[johanlien]

Re: Please Help Viewsonic VX2235wm NO Light

already test it fuse read less then 1.0 ohms
IC P605 BD7B33 S-G reading Under 30ohms S- D reading Under 30ohms it's mean this ic shorted?

So we must change this 2 IC?

[retiredcaps]

Re: Please Help Viewsonic VX2235wm NO Light

IC P605 BD7B33 S-G reading Under 30ohms S- D reading Under 30ohms it's mean this ic shorted?

So we must change this 2 IC?

To ensure it is really shorted and not affected by nearby components, desolder and repeat ohms measurements. If still under 30 ohms, I would suggest replacing both.

[johanlien]

Re: Please Help Viewsonic VX2235wm NO Light

where can i find this IC? the ic must same P605 BD7B33? or can use p605 BZ6F13 or p605 XXXXXX?

[seanc]

Re: Please Help Viewsonic VX2235wm NO Light

I'd try replacing the capacitors first.
These monitors (including my own) commonly fail with bad caps. I know they haven't bulged, but they could have dried out.

[jetadm123]

Re: Please Help Viewsonic VX2235wm NO Light

where can i find this IC? the ic must same P605 BD7B33? or can use p605 BZ6F13 or p605 XXXXXX?

AOP605 available from ebay.

[retiredcaps]

Re: Please Help Viewsonic VX2235wm NO Light

where can i find this IC? the ic must same P605 BD7B33? or can use p605 BZ6F13 or p605 XXXXXX?

Try

http://www.findchips.com/

On some datasheets, it will tell you the naming convention. For example, P605 might be the actual part number and BXXYYZZ might be some code where XX YY ZZ represent date, year, batch number, sizing, etc.

[johanlien]

Re: Please Help Viewsonic VX2235wm NO Light

Hi bro I have already change two AOP605 IC but the Problem is same no backlight.

please helppp

[alexanna]

Re: Please Help Viewsonic VX2235wm NO Light

Hi bro I have already change two AOP605 IC but the Problem is same no backlight.

please helppp

Have you verified that you have voltage going to and through the glass fuse on the top side of the board? I would suspect to see either 12 or 14volts
Al

[johanlien]

Re: Please Help Viewsonic VX2235wm NO Light

Have you verified that you have voltage going to and through the glass fuse on the top side of the board? I would suspect to see either 12 or 14volts
Al

how to verified sorry iam noob

[alexanna]

Re: Please Help Viewsonic VX2235wm NO Light

how to verified sorry iam noob

Voltmeter negative lead, on a ground screw that's attached to the case.
Positive lead very carefully to each side of the glass fuse. You will be making two measurements.
Use auto ranging or 20volts DC scale.
In your picture it's the fuse just to the right of the transformer with the yellow tape on it.
Al.

[jetadm123]

Re: Please Help Viewsonic VX2235wm NO Light

Please post a clear photo of the bottom of your power board. These Delta made boards also have several surface mount fuses that need to be checked.

[johanlien]

Re: Please Help Viewsonic VX2235wm NO Light

Voltmeter negative lead, on a ground screw that's attached to the case.
Positive lead very carefully to each side of the glass fuse. You will be making two measurements.
Use auto ranging or 20volts DC scale.
In your picture it's the fuse just to the right of the transformer with the yellow tape on it.
Al.

the result is 19v but my multitester only have 2.5, 10,50 dc scale so we use 50v DC scale

[johanlien]

Re: Please Help Viewsonic VX2235wm NO Light

Please post a clear photo of the bottom of your power board. These Delta made boards also have several surface mount fuses that need to be checked.

this the bottom picture

[jetadm123]

Re: Please Help Viewsonic VX2235wm NO Light

this the bottom picture

The photo is too blurry to see any components clearly. Try looking on the bottom of the board for any components marked FXXX (where XXX is a number). With power off and monitor unplugged, measure the resistance across the fuse. If it's less than 1 ohm, it's good.

[alexanna]

Re: Please Help Viewsonic VX2235wm NO Light

The photo is too blurry to see any components clearly. Try looking on the bottom of the board for any components marked FXXX (where XXX is a number). With power off and monitor unplugged, measure the resistance across the fuse. If it's less than 1 ohm, it's good.

Yes please post a clearer high resolution photo of bottom of the power supply.
A better picture of the top would also be good.
Delta boards are very good about identifying pin voltages from the logic to the power supply, what are they?
Al.

[johanlien]

Re: Please Help Viewsonic VX2235wm NO Light

The photo is too blurry to see any components clearly. Try looking on the bottom of the board for any components marked FXXX (where XXX is a number). With power off and monitor unplugged, measure the resistance across the fuse. If it's less than 1 ohm, it's good.

measurment result On bottom board fuse its less than 1 ohm