Monitor clicks like clock - is it fixable?

[Muse]

Someone put a monitor on the sidewalk - it's the yearly recycling time. Nanao 550iw 17", this is a GREAT monitor, IF it works! On the back it says it was made sometime in 1993. I'm looking at a Nanao 17" CRT right now, made a little later, an F2-17ex, and I love it. It's the only color monitor I've ever had. It's a little small by today's standards but I think it looks as good as the day I bought it around 1995 or early 1996 for about $1000. Has cool thumbwheel. So does the one I found today, but it seems to have a problem. I hauled it home because I have a 2nd system but no monitor (well, I have a 14" B&W, that's actually a 12" in Windows!). I hooked it up and turned on the box and monitor and the monitor made the usual beep but I saw nothing on the CRT and it started clicking like a clock. 3 or 4 clicks every second or so. I assumed it's screwed up and put it back on the sidewalk where I got it with a sticky on the tube saying "Does Not Work". Is it possible that it can be reasonably fixed or even fixed myself?

Thanks.

 

[Muse]

Bump

 

[bwass24]

Without knowing a little more it's hard to be of much help. My suggestion (from many years of experience) is to open it up and take a VERY close look at EVERYTHING. The clicking is actually a mechanical relay, which was common on some older monitors. The only real reason to use a relay is to use a low current signal to switch a much higher current signal. The fact that the relay is clicking on and off tells me that the power and signal source are OK, but something on the output side side of the relay is at fault. Sorry I can't be more specific.

Again, my experience has taught me that at least 90% of things that are wrong/defective can be seen with your eyes only if you look carefully enough. Check EVERY connector, wire, component, solder connection, etc. You'll probably SEE the problem, and then you can go about fixing it. I recently found a Sony 19" flatscreen CRT on the sidewalk, also with a yellow sticky that said "Basura" (trash, in Spanish). I took it home, opened it up and found a small connector only half seated. I pushed it in all the way and now the monitor is perfect.

Just keep your eyes open and you might find the prob.

 

[Muse]

Thanks very much for this. I will see if it's still there and if it is, I will bring it home today, open it up and inspect it carefully and try to find the problem. If I can I will be really happy! If I can't, well, I tried. Today's just Wednesday and I don't think they are picking up the stuff until at least Friday, so I have time to go back and put it back on the sidewalk if I can't get it to work.

 

[bozo1]

What resolution was your video card set at? If you try a resolution and/or refresh rate that a monitor can't handle, many of them will just sit there and click.

 

[Muse]

Originally posted by: bozo1
What resolution was your video card set at? If you try a resolution and/or refresh rate that a monitor can't handle, many of them will just sit there and click.

It was set at 1024 x 768, but that's not the problem. That monitor can display that to spare.

Even when you don't have a VGA cable attached to the monitor it makes that clicking sound. It's a waltz, three beats to the measure and with a frequency/measure of about once per second. When you turn on the monitor power, it makes the familiar beep-beep-beep sound that it should. However, when you hit the button on the front that activates the display, it immediately starts making that clock-like ticking. I have the cover off and am looking at the electronics but nothing sticks out at me. I smell nothing and see nothing that strikes me as out of the ordinary. All the connectors that I can see seem to be firmly in place.

 

[ScottMac]

First: DON"T OPEN THE MONITOR IF YOU DON"T KNOW WHAT YOU'RE DOING - there's some likely to be some painful voltage hanging around in there, even if it's turned off and unplugged.

Next: It sounds like a high voltage problem (flyback transformer arcing) - not easy to fix if you don't know the systems. I s'pose it could be a relay, but chances are it's soldered in place, and chances are the relay is not the problem, the sense/switching circuit would be the problem.

I vote for tossing it


FWIW

Scott

 

[Muse]

Originally posted by: ScottMac
First: DON"T OPEN THE MONITOR IF YOU DON"T KNOW WHAT YOU'RE DOING - there's some likely to be some painful voltage hanging around in there, even if it's turned off and unplugged.

Next: It sounds like a high voltage problem (flyback transformer arcing) - not easy to fix if you don't know the systems. I s'pose it could be a relay, but chances are it's soldered in place, and chances are the relay is not the problem, the sense/switching circuit would be the problem.

I vote for tossing it


FWIW

Scott

I was aware that there's probably dangerous voltage hanging around in there on the capacitors and have been acting accordingly. Of course, it doesn't help when I have to plug it back in to see if the problem's fixed because that just recharges the capacitors. I'm with you here, and thanks for the analysis. I'm going to screw things back together and put it back where I found it.

 

[ScottMac]

Good Idea....

The capacitors aren't the thing that'll send you flying (though they can give you a serious poke). The CRT (acting like a capacitor) stores a charge at the high-voltage value...usually better'n 10KV (in the olden days, some TVs were 25-50KV on the anode of the CRT).

Before you work near the CRT, it should be discharged ... several times ...

...or better yet, if you don't know about the stuff, it's much safer to just stay out.

Nice try though, I also hate to see "good stuff" tossed.

Take care

Scott

 

[boi]

Yeah, theres some dangerous voltages in there. When I had a messed up monitor, I opened it and I touched a metal plate in there. It freakin shocked the hell out of me. After that I just threw the monitor away because I was scared of it =(

 

[Muse]

Originally posted by: boi
Yeah, theres some dangerous voltages in there. When I had a messed up monitor, I opened it and I touched a metal plate in there. It freakin shocked the hell out of me. After that I just threw the monitor away because I was scared of it =(

Fortunately I didn't get shocked. I did see a label in there that said there was 27 kv. I did practically no poking while power was on, and was mindful of danger, but I think it was definitely wreckless to do what I did. Never getting near that thing again and will probably never open a monitor again... Thanks for the help, folks. I had to try. That was a GREAT monitor, IF it worked. It must have cost near $1500 new in those days, maybe more. Said on the back it was made in Dec. 1993.