So I just fried the second computer monitor in less than a year. I had a 17″ monitor that lasted over 8 years. Then I got a new HP and it died in about a year. I replaced that with a NEC 19″. All were CRT’s.
After asking around, the only plausible theory is that I may have voltage fluctuations that fried the HP and NEC monitors.
So using a multimeter, I got readings of ~122-124 at various points around the house. I tested the receptacle directly as well as the surge supressors that I am using.
The digital multimeter is set for V ~ 200. Is that the correct setting?
If yes, are readings of 122-124 normal?
Are the levels safe for electronic equipment? I have a 36″ tv and a home theatre tv that are ~8 years and they don’t seem affected. The only casualty to date are the monitors.
Replies
No real input on whether those voltages are out of line. That is the right setting on the meter.
I think you have just had a run of lousy monitors. Might help to double check your surge suppressors....some are one time use, as it were.
My advice is to ditch the CRTs and go with LCDs, in any case....lots less power consumption...
Spend about $65 on a UPS battery backup. Mine can be set to disconnect from line if over or under what ever voltage you choose. I use the APC brand, it has some pretty cool software and usb tie-in to the computer. It even logs what fluctuations/events have occurred.
I believe 122-124 is acceptable though. But that was only a point in time check, it may be spiking at other times. The setting on your meter should be the correct choice.
Edited 6/20/2008 12:10 pm ET by rasconc
Which APC model do you have? I couldn't find anything under $100 that had voltage fluctuation protection.
http://www.apc.com/resource/include/techspec_index.cfm?base_sku=BN600
The software can be set to intervene if under 97(highest) and over 127 (lowest).
http://www.apc.com/resource/include/techspec_index.cfm?base_sku=BN600&tab=Software
Bob
Edited 6/21/2008 9:48 pm ET by rasconc
I'm doubting the running voltage is the problem. Mine runs between 117-124V, often with brownouts during the day/evening and a rare occasion a blackout. No UPS in site and only the cheap power stripes and cheap as can be APC power strip.
I had a 19" Viewsonic CRT monitor last for several years of many, many hours of use before some component (cap, resistor, etc.) failed and arcing toasted it. I replaced it with a bottom of the line Viewsonic and it had problems within a year. Get what you paid for.
I now have a Viewsonic 22" CRT and 20" LCD monitors and both have lived through several brownouts and at least a couple of blackouts. We get a lot of lightning around here in North GA and they seem to be weathering those storms just fine.
On the other hand, I have had electronics in the home weather much more poorly in this climate of electrical conditions. I have had two DirecTV satellite receivers die when electrical surges came through the telephone line. Lost an Xbox that way, too.
Consumer electronics just isn't designed to last. And the tin whiskers condition is only making that more pronounced in life.
124V should not have damaged the monitors.
I did fry one of surplus find monitor once that had a bad degauss problem, and used a plug-in TV degauser on it.
Did a failure analysis after I fried the monitor, deceide I put the degausser to close to the power supply board on the side of the monitor and saturated the switching transformer, causing the FETs to burn out.
One off the wall comment - most monitors have a recessed red switch on the back to switch between 220 Vac or 120Vac (EU vs USA). If yours happened to be set on 220 V, it would still probalbly work, but the circuitry would be pulling high current which may have fried it over time due to overheating.
Many of them that I have seen have a switching power supply and are speced 100-250 volts and not switch. Just need the right power cord..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I once was a monitor repair tech, and the CRT monitors were for the most part junk. Sometimes they would last longer than the CRT, but that was rare.
I think you just had bad luck. Also, were the last two monitors new? If not, they probably were already fatigued from use.
In case anybody wonders, the most common failure was horizontal output transistors, usually caused by a failure in the flyback or tripler. Followed by thermistors in the degause circuit, anything connected directly to the CRT, switching power supply transistors and capacitors, cheap cracked printed circuit boards, probably last was the CRT itself.