Iiyama Prolite E481S power supply problem: Solution

[jankro]

Iiyama Prolite E481S and other models from this manufacturer have suffered from power supply problems.
This unit started sometimes from standby or turned off (even power light) after 10-15 minutes and would not start again for awhile.

The L101 on the power supply board had a dry joint and so did the power switch.

Hope this helps someone else

JMK

[davidavdav]

Thanks JMK,

I had exactly the same symptoms with the same monitor. I did look for the L101, it seemed OK, but I decided to re-solder all contact points with components that had thicker wires, figuring that currents were larger for those.

And now the monitor works again!

Cheers,

---davidavdav

[NoobZ]

Hello,
I know this topic is old but i believe i have the same problem..
I have too the prolite e481S
But i dont understand what does it mean "L101" ?
What have i to do ?
In short, actually my monitor even doesnt want to work for a while, i just see the blue led flashing..
Thank you !
p.s (i'm french so sorry for my english..)

[Guest]

Hi,
Just repaired a ProLite E481S and thought I would pass on the details.
Fault:-
Blank display flashing blue LED in POWER button.
Fix:-
Remove stand, remove 5 screws from back of monitor. Use thin steel ruler(s) to unclip plastic back of case.
Remove pillars from 'D' and DVI-D connectors and single screw from metal cover and slide downwards to remove, exposing 2 electronic panels.
Examine condition of main smoothing capacitor C905, 150uF 400V (large capacitor laying down next to IEC mains inlet). Mine had signs of weeping electrolyte. (has about 350Vdc across it when powered up).
REPLACE!
Examine condition of C914 and C915 1000uF 16V.
Mine were bulging due to being toasted next to the vertical heatsink. (common fault on SMPSU's BTW)
This dries them out and they fail. REPLACE!
Whilst these capacitors are out check the double diodes (TO220) on the heatsink. Mine were OK.
Outcome:-
Replacing these capacitors cured the fault.
Hope this helps........
Dave

[zigmund]

Had the same problem. Although I'm not experienced with soldering, I managed to fix it by soldering the contacts of L101. Problem solved!

Thnx!

[SnowMan007]

I tried resoldering L101 - no luck. Searched for failed capacitors and found two. I've not soldered components on a PCB since I was in college 25 years ago!
However, I managed to extract the blown caps and buy two more (16v 1000uf) and replace them. Bingo, the monitor works again.

Well worth the 18p!

Cheers

[MRB]

Hi, I realise this is an old thread, but thought it was worth a shot anyway

I have the same problem. I have access to the two circuit boards (thanks to the instructions!), but I can;t for the life in me find L101 - Any pointers would be much appreciated.

Many thanks,
Mark

[MRB]

Found the elusive L101 (actually my son did JUST after I posted the last reply).

For anyone else who needs it - its the doughnut shaped component, with copper wire wound around it, in one of the coners of the board. The real giveaway is the white writing next to it that reads "L101"

thanks for the help all...

[sophierose]

Monitor all dead, changed all caps, no cure, then found a bad soldering at L101 on power board, redone and fixed!

[kbs1]

Hello, I know this is an old thread, but my iiYama ProLite x486s monitor has just stopped working. I have tracked it down to be (probably) power supply / inverter board issues.

The monitor is dead. When assembled (in plastics), it only shows orange (sstandby) LED. It's supposed to show blue led when ON. This led shines, but shines so little, that it's invisible through plastic.

When disassembled, the blue led is visible - faint - and display is dead, no picture.

I have found this thread and found L101 (on mine it's L901) dry joints. Also found dry joints on other places on the board. Resoldered - no luck, still the same. Capacitors are OK. Board is visually OK. Transistors are not shorted.

The problem, I suppose is that on the main connector (to monitor main board), the voltage on pin 12 is 12V when in standby - however when turned on (faint blue led shines), the voltage drops to 9V. On pin 3 (5V line), the voltage drops to 1V. I think the monitor wants to display "no signal message", because after a while it goes to standby again (strong orange led shines) and the voltage again rises up to 12V/5V on said pins of connector.

I'm just guessing here. Also, when I press the power switch on the monitor, the PSU (don't know which part) makes a high pitch / frequency noise for about ~2 seconds [voltage is now STILL 12V/5V BUT blue led shines faintly anyawys], after this period the noise stops (complete silence) and the voltage drops. After a while (~10s) the monitor goes to standby, no noise from PSU any more, and strong orange led shines.

This repeats when I turn it off via power button and on again.

It just completely died all of the sudden. No issues before whatsoever. Any help on what parts to check or what could be the problem is realy nice.

Also, the psu partn number is 715G1236-3-AS, but I have been onable to find a datasheet for it.

Thanks!