View Full Version : Knoppix STD initial boot seems to have destroyed my monitor

05-01-2004, 01:38 AM
I have been using Knoppix for several days with no problems. I tried Knoppix STD today. The multi colored text screen seemed to all look ok until the graphic screen started to display. I heard a high pitch noise and then my screen went blank. It stayed blank. I can't even get a green/amber light on it now, even on other machines I hook it to. The fuse inside is ok. It appears the boot process has destroyed my monitor.
It happened the very first time I booted it. I had been using the other Knoppix with no problems at all. ANYBODY GOT ANY IDEAS??? I hooked up another monitor to my computer and I can boot into windows and see everthing on a different monitor, so at least my graphics card didn't take a hit.

05-01-2004, 10:34 AM
the hight pitched noise was possibly caused by the kathode wire burning up. not much to do ecept replasing the tube. depending how old the monitor was it could be to high frequency but...

05-01-2004, 06:04 PM
i agree. STD was trying to get your monitor to have a high refresh freq. then it could support. so More or less your monitor is useless. You could repair it but it woulod cost almost as much as a new one.

05-01-2004, 06:26 PM
This is my number one concern about KNOPPIX(and its derivatives). The modeline in the supplied XF86Config-4 is just not necessary as XFree86 4.3 already has very good in-built defaults.

On my notebook, I needed to delete all of them or else I just got complete lockup, luckily it was not fried.

IMO, this is a case of getting the most impressive display setting(resolution, frequency) that goes overboard and being harmful.

05-01-2004, 08:16 PM
My knoppix 3.3 hd install had resolutions/refresh rates that my monitor just really didn't care for that wouldn't budge when applying the changes in video section of kcontrol. And being female, I could hear the very high pitch of a slightly unhappy monitor before anything was overdriven too long. I felt it was something to do with the ddc probings since I had to modify myXF86Config-4 and literally commented out modelines I felt was not safe long term. It is a newer monitor and it probably would have given me an outofrange if it was set too high but I don't want to overdrive it marginally, either. Oddly, I had no trouble with kanotix and haven't had to edit the modelines or anything other than set a refresh rate I was comfortable with and had a good resulting geometry. Newer version of xfree, maybe?

05-05-2004, 05:41 AM
The high pitched whine can come from two places inside the monitor, most likely it toasted the output transistor on the flyback transformer, this transistor controls the horizontal and high voltage of the monitor. these transistors typically cost about 30.00 cdn, and are easy to replace. three solder connections, and two screws. they are oval in shape, and are silver in color. sometimes the whine lasts until the circuit board trace that sullpies power to this transistor melts, another easy repair, change transistor, check circuit board and repair if needed.

the other place that can produce a whine is the vertical output transistors, they are a matched pair, and can usually be identified by the appearance of a darkened circuit board directly under where they are mounted, as well as power resistors in close proximity that will also show signs of heat. these transistors are a matched pair, and must be both changed even if only one is damaged. they are usually mounted standing up on three legs, and have a bright metal heat sink on them. you could be lucky, and a solder joint heated up and failed, again a quick fix. the transistors can range between 20.00 to 40.00 cdn for the pair, easy to change.

heating on a circuit board can cause metal fatigue on the solder joints, and result in hairline cracks, most cracks can only be seen with a good magnifying glass.

a good electronics shop should only charge about 40.00 for labor to repair plus parts.

good luck.