STAPLES SP9106 -Strange behaviour.

[infamous7x]

Hello, Recently I bought a second hand Staples 19" display (I think its a AOC rebranded display), anyway, when i got home and hook it up to my computer, 2 things happened.

1- It either shut off completly, or randomly restart itself.
2- At some point, my mouse (USB and trackpad) either become laggy, unresponsible or not move at all, but not my joystick (Little blue dot in some laptops) or Laptop's own keyboard , Also my USB keyboard fail, I can even hear the sound Windows plays when you disconnect a hardware.

So, I pry-opened the external power brick of the LCD and found a blown cap near the output cable, so I replaced it with a brand new one, also I am suspicious about the 400v main cap, because I think I saw some leakeage in one of the connectors, and also, the transformer make a noticeable buzzing sound.

I hook everything up again and.... same thing!

So i decided to take apart the LCD, then, I found another 3 blown caps (25v, 220uF) in the power connector board, so I also replaced these, then again I put everything back together, Et voilà, no more shutting off. But! the mouse lagging, keyboard disconnecting thing still happens, until I unplug the VGA cable.

Same thing happens in another laptop.

WHY? Could it be a defective power supply?

[lexwalker]

Re: STAPLES SP9106 -Strange behaviour.

Please post pictures of the external brick board as well as the monitor internals. And yes, there is a possibility of power supply problem especially the +5V rail for the USB section which could be derived from the main power rail using a step down linear or switching regulator. That one have to trace at the USB section itself...

Also do state the brand and series of replacement capacitors used. Most LCD monitor power supplies uses low impedance or low ESR type capacitors, instead of run-of-the-mill standard capacitors. Badcaps and/or wrong capacitors can one of the sources for transformer buzzing issue...

[selldoor]

Re: STAPLES SP9106 -Strange behaviour.

Have you (or can you borrow) another power supply to test the monitor with?

They are usually 12volts 4 Amps for this size monitor - what is the rating on yours.

Lex - I dont think the power is split down to 5v until inside the monitor so perhaps
a faulty voltage regulator?

[lexwalker]

Re: STAPLES SP9106 -Strange behaviour.

They are usually 12volts 4 Amps for this size monitor - what is the rating on yours.

Lex - I dont think the power is split down to 5v until inside the monitor so perhaps
a faulty voltage regulator?

Not referring to the external brick for the +5V regulator, rather on the internal boards (the reason I've mentioned "That one have to trace at the USB section itself"). Possible there could be a badcap around that +5V voltage regulator. Also a bad or failing power supply could create such symptoms mentioned (seems to be insufficient power, note the part "until I unplug the VGA cable")...

[infamous7x]

Re: STAPLES SP9106 -Strange behaviour.

I found one picture of the power connector PCB, sorry i dont have a camera right now.

http://item.taobao.com/item.htm?id=14008538100

Also I forgot to mention, theres no USB devices hooked to my display, it does have a USB HUB, but its independent from the display.

Also, all the original caps where CapxOn, and I replaced them with same specs Sc ones.

I'll try to find a replacement powerbrick today to see if that solves the problem, its a 12v 4.16a power supply.

[selldoor]

Re: STAPLES SP9106 -Strange behaviour.

Ok so are you saying that your PC provides the 5v to the monitor USB hub
and you are using the hub to split the power from the pc to mouse and keyboard
If that is the case I suspect there is a problem with the pc supplying power to the hub and videocard?
Can you plug joystick direct to a separate usb on the pc.

I know your machine needs 4.16 amps but is that what your brick is rated at?

[infamous7x]

Re: STAPLES SP9106 -Strange behaviour.

Nope, I'm not using the Display USB HUB (Also the HUB is completely separate from the display, is encased somewhere else). The only thing pluged to it is the VGA cable and the power supply.

I've just got my hands on a Sharp 12v brick, but I'll need to swap the connector, lets see how that works.

[infamous7x]

Re: STAPLES SP9106 -Strange behaviour.

My display sticker says 12v, 4.16a (MAX), and the brick says 12v 4.16a. Haven't checked my new brick amps yet.

[selldoor]

Re: STAPLES SP9106 -Strange behaviour.

Ok think ive got it now you are using it as an external screen on a laptop.

which is probably struggling to provide the power to everything.

By rights the monitor shouldnt affect the usb but some vga cables do have a 5 volt line so perhaps try a different vga cable check the pins and sockets and look up
vga pin out - 5 volt on google

[infamous7x]

Re: STAPLES SP9106 -Strange behaviour.

Well, everything is working great now ! Replaced the power brick with a 12v 3.6amp SHARP LCD Adapter, now everything is AOK, even played some demanding PC games with no strugle.

Thanks everyone for your help

[selldoor]

Re: STAPLES SP9106 -Strange behaviour.

Good - but we still dont know what was wrong and problems that fix themselves often tend to come back.

[brianh]

Re: STAPLES SP9106 -Strange behaviour.

I have one of these monitors too, and it comes on at first, but after about one minute it starts to flicker, then it shuts off. I do not have the original power supply, but I'm using a PC power supply with more than enough power on its 12V supply. The three CapXon capacitors looked fine, but I replaced them anyway. No improvement. I also re-soldered many joints on the LCD driver board. No improvement.

[selldoor]

Re: STAPLES SP9106 -Strange behaviour.

Please can you update your profile with country/mains voltage

https://www.badcaps.net/forum/showthread.php?t=39740