Re: Syncmaster T190 - a headache

With the main board on (KEY1 to 3.3V), I get 50mV of ripple on the 5Vdc line. The other lines seem okay.

On photo 1, there's the voltage line
On photo 2, the small peak at the highest ripple amplitude is zoomed at 20us/div
Photo 3 reveals the ~10 MHz harmonic content, provably caused by the digital circuitry....

Re: Syncmaster T190 - a headache

I changed the 3 capacitors with Fujicon low ESR and no luvk - still dead. I'm going for the osciloscope.

Re: Syncmaster T190 - a headache

Many thanks!

So judging from the troubleshooting guide, the problem is still in my power supply board.

Hello to everyone,

I recently bought a used display – [U]Samsung Syncmaster T190[/U]. When I brought it home and plugged it into my computer, I found out it's completely dead:
-No backlight
-No image
-No power indicator LED glowing
-No reaction from the touch sensor button or any button at all.

So I decided to try repairing it. I have repaired a few LCD screens in the past and a few SMPS by recapping them, so I thought “why not”?
I took off the power supply board and examined it. There were two bumpy leaky capacitors visible....

Re: New Members - please post your introductions here

Hello,

I'm Alexander from Bulgaria. I like and do technical hobbies as electronics, woodworking, hi-fi audio. I've joined here because I am trying to repair a Syncmaster T190 monitor - hard one!

Best regards to everyone!