View Full Version : Commodore 1950 monitor tube fault?

31st December 2014, 11:34
Hi all,

Hoping someone with a bit of monitor expertise may be able to tell me if I'm wasting my time trying to fix and would be better off trying to track down a replacement tube.

I would really like to salvage it if possible as the case is absolutely mint :-)

No matter what settings etc. are selected tube retains nothing but a solid white line from left to right... also remains same whether connected to video source or not.... I have looked at all the pointers on BBOAH etc and they all seem to relate to switch issues or completely blank screens so not really relevant. Is it a collapsed tube? Beyond repair? Better off looking for a tatty cheap one up for sale with a working tube and swapping the case?

Thanks vey much in advance,


81013 81014 81015

31st December 2014, 11:49
It is caused by missing vertical deflection (keep brightness down to prevent future tube damage).

Most common causes: deflection coil broken (tube neck coils, contains both horizontal and vertical), cable/connector broken, (vertical deflection cable = cable that does NOT go near big transformer), vertical amplifier/chip broken, usually near the cable connector.

Tube is fine. (Image is visible, line is white, no rainbow colors)

31st December 2014, 13:49
Fantastic, thanks Toni... some great pointers there, much appreciated

31st December 2014, 14:17
toni is pretty much spot on,this is known as a "vertical collapse" your tube is fine you just have a failed part normally the parts responsible for that failure is very cheap:)
and the fix is reasonably simple.

i would also suggest not having this set on for extended amounts of time due to its failure,or at least turn down the brightness.

31st December 2014, 14:40
Thanks Roy... I think I will just discharge it and have a look with a macro lens for dry joints around the connectors... just had a trawl through Youtube for vertical collapse and dry joints and heat damaged connectors seem to be a very common cause.

31st December 2014, 15:05
yes,dry joints are a problem in old crt's,but dont get our hopes up if it isnt that.

just be careful bud,i dont want to see anyone get hurt.

you will probably have to pull out the main board for inspection,youll be looking around the area with four thick coloured wires coming from the deflection coil.normally.

31st December 2014, 16:23
Well, FOund the cables from the deflection coil, I have had a good look around the board and daughterboards, its very clean inside and cant see anything obviously amiss..... sad times :-(

I'm fine with discharging and where to not to poke as I've installed a few Hantarex arcade monitors but unfortunately beyond dry joints and fuses my repair skills come to a grinding halt.

31st December 2014, 17:46
well,can have a look at the monitor for you if you pay for shipping both ways and the parts and labor.

ill be looking at a monitor anyway soon from someone else here on amibay so its of no consequence to me.(after the christmas holiday)

2nd January 2015, 08:04
Fantastic, thank you Roy.... I get down to Birmingham once a month so if its ok with you I will message nearer the time and see if its convenient to drop it off on the way through rather than request Royal Mail compact it for me :-)

2nd January 2015, 09:08
no worries,let me know so im in.

ill probably have it a while anyway while i work on it:)
so if time is not a problem i dont mind doing it:)

p.s ive got hold of the service manual for it,so that will make life a bit easier with the fault finding...

2nd January 2015, 11:18
I hope you'll eventually get the monitor fixed. Very sad having to threw good old stuff away. :(

However, if you would consider it beyond repair and decide to get rid of it, would you mind saving the side door for me? I have a perfectly working 1950 in good shape, but with the door missing.