NEC XM29 Horizontal Collapse

[svensonson]

Hi guys,

one of my NEC XM29 broke recently and refused to turn back on. black screen, no high voltage or fans were spinning.
luckily I was able to sort out a replacement transformer for this monitor and found someone who installed it successfully.
Monitor is now turning back on and all fans are spinning but now it has a vertical line going straight down the screen.

does someone what else I could check for? do you think the replacement transformer is also broken? at least it does somehow turn on now.

thanks for help

[nem]

NEC XM29 Horizontal Collapse

now it has a vertical line going straight down the screen.

Uhh, two different issues here.

[PascalP]

NEC XM29 Horizontal Collapse

now it has a vertical line going straight down the screen.

Uhh, two different issues here.

Should be the same
When a monitor collapses horizontally, this means the complete horizontal images collapses to the middle.
So if everything from left to right is centered in the middle, this would show as a vertical line

[PascalP]

But your issue could have multiple causes, with arcade monitors an issue like this would most likely be a defective horizontal IC or a trace (power, ground, etc.) of that IC would be interupted...

I don't know if you have the skills to diagnose and fix this?
Or you could find a monitor/tv repair guy in Germany to have a look at it.

[svensonson]

I do not have such skills to troubleshoot this problem but luckily I found a retired repairman who fixed these crt`s for tv stations here in Germany in the 80/90s. I will pay him a visit tomorrow morning and leave it there....fingers crossed

[nem]

Should be the same
When a monitor collapses horizontally, this means the complete horizontal images collapses to the middle.
So if everything from left to right is centered in the middle, this would show as a vertical line

You're right. My mistake!

I've never seen a horizontal collapse. Tried finding one on Google and it seems to be very rare.

Mismatched tube and chassis can apparently cause it:

http://blog.allyoucanarcade.com/arcade- ... rn-lights/

Not that that helps OP at all!

[gray117]

Probably all part and parcel of the transformer going out - hopefully just a bust capacitor within deflectors probably near flyback/transformer... But there's probably so many boards and circuits inside the xm vs normal arcade monitor it might be anywhere!... vertical collapse maybe more common on normal monitors but all bets off with something like xm, collapse is often strain (incompatible signals) or power related though so hopefully not too different. Good luck!

[svensonson]

yes, thats also the first thing the guy told me this morning. he is going to check first all caps and Transistors nearby the transformer using his oscilloscope. horizontal deflection and also the seperate power board which is responsible for the horizontal sync capabilities.

[svensonson]

Update:

this genius was able to repair my xm29.

a few caps and high voltage transistors were gone on the hv board next to the transformer (like gray117 said ) and also on the seperate horizontal hv sync board or whatever it is. he took the time to replace most other caps/transistors as well

[ryu]

Awesome!

How did you find that guy?

[LDigital]

The biggest worry about monitors is finding an engineer to fix them. Most regular tv repairers by me sacked off CRT long ago and won't touch them for any money. These single board lcd sets have spoiled them

[svensonson]

yes, this guy repaired my rear projection tv 15 years ago and for some reason I had his number still written down in my notes. all other repairmen (especially younger than 50y) kicked me out of their permises when I asked them to repair a broadcast crt.