Viewsonic VG800 LCD monitor power problem

Hi,

Working without a service manual on this one and have 2 more just like it. Plug power in and it sorta flickers on and off, power/status LED flickers different colors several times and finally stabilizes at a stedy flashing green about once per second and the backlight pulses about the same frequency. I noticed a myriad of SMD caps and checked most of them for high ESR, most are pretty decent, a couple are marginal but seem to be alright. uPC supply voltages seem pretty solid so I'm kinda stumped. Anybody seen this problem before, being as I have 3 of these all failed near the same time I'd suspect it's a common problem or soon will be.

Thanks, Benjamin Jennings, MCP

Reply to
Benjamin Jennings, MCP
Loading thread data ...

Two things:

One: do they all have the same symptom ? If so have you plugged in a valid input ?? (to EACH)

Two: if they do not have the same symptom, what are the other symptoms ?

Thinking of it this way can get you down to board level real fast, but don't rush to sell anything that works, use it as a reference to fix another.

Happens all the time.

JURB

Reply to
ZZactly

I have similar behavior but monitor shows screen after several minutes. Do you by any chance remember what was the problem with this monitors ???

Reply to
SolarAngel

Check with the folks at

formatting link

PlainBill

Reply to
PlainBill

Replacing caps fixed my Viewsonic - watching it right now.

Mark Z.

Reply to
Mark Zacharias

Thaat is a common problem. However I didn't feel like explaining ESR, explaining why the caps he could buy in a $5.00 bag at Radio Shack weren't good enough, why spending a few bucks less and waiting a couple of days for delivery was a good idea, and above all trying to troubleshoot without pictures.

PlainBill

Reply to
PlainBill

responding to

formatting link
, SolarAngel wrote: I know about bad capacitors, but wanted to know for sure is this common problem with all ViewSonic models, and does it result in this kind of problem - waiting for several minutes for screen to light up.

have found service manual for my model on net, and wondering to replace bad caps my self. but also was wondering to replace bad caps with little higher voltage capacitors. for example 50uF 20V to replace with 50uF 40V. could this produce some problems or to go with this plan!?

but first need new monitor (how else to read service manual), and funny thing I have found exactly same model for free, only difference second one was sitting 5 years in box LOL need only to drive to uncle to get it ;)

Reply to
SolarAngel

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.