Locost LCD Monitor repair............
Surrey Dave - 8/2/11 at 07:22 PM
Some months ago my 'not very old' GNR TS902W monitor stopped working , and developed a strange ticking noise from the speakers, I plugged in
a spare and put the GNR to one side until I could bring myself to take it to the tip.
In the meantime I did a bit of research on zee web , and came up with some interesting stuff relating to capacitors.
Apparently most often when an LCD fails its the capacitors..........
So today, before I binned it i thought ,nothing to lose and opened it up, I noticed that some of the capacitors where bulging , and although the
circuit board was quite symetrical , some of the capacitors where 16v where most where 25v.
Coincidently the caps that where bulging where the 16v ones!, so I nipped down to Maplin and bought 7 new capacitors for £2.49, came back and
soldered them in ,threw it back together and **** me it worked, my flabber was truly gasted as I don't seem to have much luck with internet
tips!
So top tip check your comp components for ' Capacitor Plague' as wiki calls it .
I have a feeling that the day my monitor was built they ran out of 25v caps, and just put in what they had , I blame the Chinese ,British Leyland
would never do that kind of thing
HowardB - 8/2/11 at 07:41 PM
well known in switch mode PSU's especially the ones that get warm,...
David Jenkins - 8/2/11 at 07:52 PM
quote:
I have a feeling that the day my monitor was built they ran out of 25v caps, and just put in what they had , I blame the Chinese ,British Leyland
would never do that kind of thing
In their defense... electrolytic capacitors need to run at a specific voltage to maintain their voltage rating (see
Wikipedia, near the end of the bit about polarity). If you run an electrolytic with a
high voltage rating at a much lower voltage, it may stop working earlier.
They do have a limited life though, even at the right voltage - they can be replaced with tantalum caps, but those are far more expensive (and are bad
for gorillas*). Electrolytics are easy to make, and therefore cheap. Some makes are better than others, but none are really long-lived.
* The place where they mine tantalum is near to where gorillas are just-about surviving - one of the added pressures for these beasts is mobile
phones, which use tantalum caps as there isn't enough space for electrolytics. More phones, more pressure on the gorillas. Sad, really.
</end gloom & doom>
[Edited on 8/2/11 by David Jenkins]
westf27 - 8/2/11 at 08:23 PM
Frank Harrison would be proud of you 
paulf - 8/2/11 at 08:36 PM
I am also using a monitor that had the same problem, I found that it is a very common problem and supposedly due to some one in China ripping off the
formula for the electrolyte in them, from another company but missing out one vital ingredient to save a few pence causing the ally inside to react
and corrode destroying the capacitor.Unfortunately that particular company produced millions of dud components affecting most types of electronic
equipment.
Paul
rf900rush - 8/2/11 at 08:50 PM
Looking at this through a a repaired monitor.
Cap's were changed, but one of the drive fets had gone as well.
Cap. problem is on a lot of products. Mother boards, PSU's etc.
Davey D - 8/2/11 at 11:34 PM
At one point there were a lot of Dell GX270 desktop computers suffereing with blown caps
Surrey Dave - 14/2/11 at 10:43 PM
Repaired a Samsung 940mw tv/monitor by replacing 8 capacitors , it madness!!
The Frank Harrison that Westf27 is my old science teacher (I think) , we went to the same school ,it was quite good 'cos it was approved!