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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Colani1200 on December 18, 2007, 07:02:00 PM

Title: killed 2 monitors in 2 weeks...
Post by: Colani1200 on December 18, 2007, 07:02:00 PM
People be warned: That old stuff ain't getting any better...

My trustworthy Philips CM8833 blew up 2 weeks ago with a loud beeping noise. I replaced it with a CM8833-II. Now that one also passed away! All that's left for me is an old 1084s right now.

I am using the PAL HighRes Interlaced, 50 Hz / 15 kHz screen mode. Is this one "unhealthy" for the 108x type of monitors? Or was it just bad luck?
Title: Re: killed 2 monitors in 2 weeks...
Post by: taunusand on December 18, 2007, 07:28:08 PM
You can probably repair thoose monitors!

http://amigahardware.mariomisic.de/cgi-bin/showhardware_en.cgi?HARDID=849

Look for "Common Problems"

The C=1084 is usually a variation of the Philips CM8833 monitor
Title: Re: killed 2 monitors in 2 weeks...
Post by: A1260 on December 18, 2007, 07:36:51 PM
that HighRes Interlaced, 50 Hz / 15 kHz screen mode. Is one "unhealthy" mother thats for sure, you should not use it on old monitors...
Title: Re: killed 2 monitors in 2 weeks...
Post by: meega on December 18, 2007, 07:45:42 PM
The 1084S is a VIDEO MONITOR. It is designed to accept interlaced video signals. That is its job.

If they are dying, it is because they are old. That is all.
Title: Re: killed 2 monitors in 2 weeks...
Post by: Plaz on December 18, 2007, 07:58:32 PM
Quote
Or was it just bad luck?

Just a run of bad luck probably. I'm guessing you bought the second monitor used? If so it probably didn't have much life left in than the first. With old equipment, if you don't replace ALL of the electrolitic capacitors, they are going to fail eventually and ususally take serveral other components with them.

BTW, 108x monitors are notorious for wearing out flyback transformers. You can get it repaired by replacing burned caps and transistors, but if the flyback is the root of the problem and not changed, it will burn again.

Plaz
Title: Re: killed 2 monitors in 2 weeks...
Post by: Plaz on December 18, 2007, 08:03:35 PM
Quote
you should not use it on old monitors...


Sure you can. But if you intend to keep it for any length of time, the old parts (caps mainly) need to be replaced *before* it burns out. Doing it after is harder and more costly.

Plaz

Title: Re: killed 2 monitors in 2 weeks...
Post by: Colani1200 on December 18, 2007, 08:06:50 PM
Quote

taunusand wrote:
You can probably repair thoose monitors!

Maybe, but I don't have the time & knowledge. I also guess it's that transformer (whistling noise).
Title: Re: killed 2 monitors in 2 weeks...
Post by: taunusand on December 18, 2007, 08:10:19 PM
Quote

Colani1200 wrote:
Maybe, but I don't have the time & knowledge. I also guess it's that transformer (whistling noise).


Maybe just a bad soldering at one of the transformers pins. Try it :-)

Lucky my, I have CM8833, C=1084 and C=1071  :-D
Title: Re: killed 2 monitors in 2 weeks...
Post by: Colani1200 on December 18, 2007, 08:19:49 PM
Quote

taunusand wrote:

Maybe just a bad soldering at one of the transformers pins. Try it :-)


I already heard about that and tried it on the CM8833, waste of time... Dunno about the CM8833-II yet.

I could kick myself, sold an almost mint 1085s a few weeks ago because I thought 3 monitors is more than enough...  :roll:
Title: Re: killed 2 monitors in 2 weeks...
Post by: taunusand on December 18, 2007, 08:39:51 PM
I think it is worth a try :-)

Yep, if you sell something, you will need it sooner or later.
Worse, you could have thrown it away  :-o

I just ordered an Amiga3000 with a C=1960 monitor, saved from been dumped in a container.. Lucky me!!
Title: Re: killed 2 monitors in 2 weeks...
Post by: da9000 on December 19, 2007, 12:42:27 AM
If 2 monitors died on the same computer, it could also be not coincidence. One time I clipped a capacitor on a video card and it blew a rather modern monitor within a day. So, if you messed around with the innards of the computer, go back and take a look, maybe you messed something up. Otherwise, most likely coincidence.

Good luck
Title: Re: killed 2 monitors in 2 weeks...
Post by: actung_bab on December 19, 2007, 01:48:53 AM
if it makes u feel better l did the same mind you
my mum put a coat over the back of one when it was left on by me.

so came home and oh @## another dead.

l allso had flash commdore 1942 montior just stop working also

doesint seem to be many of those high end screens left.

only 1084s l have another 3 know . one has loose vga connector

and l have to support with my car face plate holder underneath

2. the powe swtich is broken so taped it to the on postion.

3. aghh yes somone has but wrong connector on so it male input.

so out 3 1084s screens not the best.

happy christmas anyways. ur not alone :idea:
Title: Re: killed 2 monitors in 2 weeks...
Post by: Plaz on December 19, 2007, 02:50:24 AM
Everyone definitly check out this thread if you haven't already....

SCAN DOUBLER GETTING CLOSER and in beta now.. (http://www.amiga.org/forums/showthread.php?t=47197)

Plaz
Title: Re: killed 2 monitors in 2 weeks...
Post by: AMC258 on December 19, 2007, 03:55:13 AM
Beware Daewoo monitors!  C=1084(S) monitors are manufactured by several companies.  I have only owned the Daewoo ones, but I have schematics for the Philips.  The Daewoo ones are greatly inferior and are garbage.  Prone to self destruction when they get to be 5 years younger than they are now!
Title: Re: killed 2 monitors in 2 weeks...
Post by: alexh on December 19, 2007, 09:35:39 AM
Quote

A1260 wrote:
that HighRes Interlaced, 50 Hz / 15 kHz screen mode. Is one "unhealthy" mother thats for sure, you should not use it on old monitors...

Another great reasoned, technical answer from the master.
Title: Re: killed 2 monitors in 2 weeks...
Post by: McVenco on December 19, 2007, 10:16:10 AM
Quote
A1260 wrote:

that HighRes Interlaced, 50 Hz / 15 kHz screen mode. Is one "unhealthy" mother thats for sure, you should not use it on old monitors...


The only 'unhealthy' thing about Interlaced screenmodes is that it's impossible to look at for longer than 10 seconds without getting some sort of pain behind your eyes. It doesn't do any more harm to the monitor than other screenmodes.

The best thing to do to save your old monitors is not using them. :-)
Title: Re: killed 2 monitors in 2 weeks...
Post by: pulppure on December 19, 2007, 12:50:41 PM
I'm an old amigan and I saw that some of you have the schematics for the Philips CM8833-II (1083s like) can you PM me please ?

I haven't found them on the web (only the ones for the Commodore and I'm not even sure they are the right ones as there were different models of the 1083s)

So this monitor went dead a month ago, now the only thing it does is a black screen and whistling noise, which makes nice fading modulations when I turn it off... you can listen to it here :

http://pulppure.free.fr/amiga/moniteur.wav

Do you have an idea of what I should replace first : flyback transformer, capacitors, transistors ? How to diagnostic ?
Title: Re: killed 2 monitors in 2 weeks...
Post by: CLS2086 on December 19, 2007, 06:35:33 PM
Hi,
change the flyback transformer and the transistors, and if you can also change the diodes.
It's quite cheap in France.
flyback transformer HR7533 (for 1084S-P1 and lot of others made by philips) : 22 euros
Title: Re: killed 2 monitors in 2 weeks...
Post by: AmigaMance on December 19, 2007, 06:41:40 PM
Quote

alexh wrote:
Quote

A1260 wrote:
that HighRes Interlaced, 50 Hz / 15 kHz screen mode. Is one "unhealthy" mother thats for sure, you should not use it on old monitors...

Another great reasoned, technical answer from the master.


:-D
Title: Re: killed 2 monitors in 2 weeks...
Post by: Tomas on December 19, 2007, 06:48:31 PM
Give it a light smack and see if that does anything  :-P
If it does, then it is most likely just some bad solder joint somewhere.
Title: Re: killed 2 monitors in 2 weeks...
Post by: taunusand on December 19, 2007, 10:03:28 PM
Quote

Tomas wrote:
Give it a light smack and see if that does anything  :-P
If it does, then it is most likely just some bad solder joint somewhere.


I agree :-)

My CM8833 had EXACTLY this problem, after I soldered the transformer the problem was solved.
Title: Re: killed 2 monitors in 2 weeks...
Post by: A1260 on December 19, 2007, 10:10:18 PM
Quote
by alexh on 2007/12/19 3:35:39


Another great reasoned, technical answer from the master.


thanks and that answer was a joke, but some must take everything seriously i guess...  :lol:
Title: Re: killed 2 monitors in 2 weeks...
Post by: Plaz on December 19, 2007, 10:38:28 PM
Quote
I also guess it's that transformer (whistling noise).


Common "whistlers" are large caps gone bad. I don't recall from memory if that model has a bi-polar cap or not. If so, it's the first one to replace. It will be sort of large, near the flyback, and labled some thing like 4.7UF 160V BP. If you haven't blown a fuse then the flyback is likely still good. There is also a lage transistor near the flyback attached to a heatsink. Make sure the legs of that transistor are well soldered too. It's difficult (and dangerous) to try and talk someone through a monitor repair. If you're not experienced, then it's probably best to take it to a good repair shop.

Why might you pay attention to all of the above? I have 3000+ repairs of video displays of every type, model and manufacture over my career. :-P

Plaz
Title: Re: killed 2 monitors in 2 weeks...
Post by: da9000 on December 21, 2007, 02:43:23 AM
I fully endorse what Plaz wrote, word for word, except his last paragraph :-) I'm no expert like him, but whistling or whizzing noises are very often big ol' caps from my personal experience.

And be careful!

@alexh:
 :hammer:
Title: Re: killed 2 monitors in 2 weeks...
Post by: rkauer on December 21, 2007, 03:07:38 AM
 ...or a broked insulation of the flyback.
Title: Re: killed 2 monitors in 2 weeks...
Post by: AMC258 on December 21, 2007, 03:23:56 AM
Or a bad horizontal sweep oscillator output.  But, that would be extremely rare.  That is usually only the case if it's an all-tube TV.
Title: Re: killed 2 monitors in 2 weeks...
Post by: circlip on December 21, 2007, 08:39:13 AM
Man, I used to have an old commodore 64 monitor (can't remember model.) It died a year ago, I was sad. I pretty much used it for everything, DVD, playstation, video recorder, etc.

I now own a very crappy tv for all of the above plugged into it, and my A500 has an old "green screen" as you can see. VERY retro!
Title: Re: killed 2 monitors in 2 weeks...
Post by: da9000 on January 10, 2008, 08:44:57 PM
@rkaur:

From my experience the flyback will more likely cause snapping sounds as it arcs. Or sound distinctly different.


Quote

circlip wrote:
I now own a very crappy tv for all of the above plugged into it, and my A500 has an old "green screen" as you can see. VERY retro!


AHAHAHAHAHA! VERY retro indeed :-)

But Circlip, there's not excuse for not getting another C= monitor. There are plenty around still. I myself only have about a dozen! Too bad you're down under... I'd sell ya one if you were closer!

Title: Re: killed 2 monitors in 2 weeks...
Post by: rkauer on January 10, 2008, 08:54:51 PM
Quote

da9000 wrote:
@rkaur:

From my experience the flyback will more likely cause snapping sounds as it arcs. Or sound distinctly different.


 Your comments are right, but my name is Kauer, Rogério Kauer...
Title: Re: killed 2 monitors in 2 weeks...
Post by: da9000 on January 10, 2008, 09:58:59 PM
My sincerest apologies Rogério! The spellchecker doesn't know you by name I guess!!! :-)
Title: Re: killed 2 monitors in 2 weeks...
Post by: rkauer on January 11, 2008, 08:13:24 PM
Quote

da9000 wrote:
My sincerest apologies Rogério! The spellchecker doesn't know you by name I guess!!! :-)


 Don't worry. Sometimes my spell checker fails, too.