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Old 07-11-2018, 02:21 AM   #1
DaemonCross
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Default HP X2301 LED Backlight Monitor Power/Startup Issues

Hi,

I have an OLD (7-8 years) HP x2301 LED Monitor that has been my workhorse for years. Just recently it's been exhibiting the FF:

Issues.

1. Powering On the monitor the day after use is a 50/50 chance if whether it works or not. The Power LED light lights up for 2-3 secs then turns off.

Unplugging and replugging the device has a -small- chance to get it to turn on fully up to the point that it searches for a signal at that point the monitor is fully operational.

2. The Monitor when fully activated is stable even when it enters standby/sleep mode it powers back up after you move the mouse. BUT when left extensively in sleep mode, after a few days or worse case a few hours the monitor shuts off.

3. After opening up the Monitor, I noticed the Flatcable (FFC) leading to the LED backlight has slight burn/melted point. But the screen still seems to display fine, save for -very- subtle hints of green on one side. Refer to images.

Repairs/Attempts I performed:

1. I have already replaced the 2 through-hole caps with new ones. Issues remain

2. Used a Different power brick with appropriate voltage. Issues Remain

3. I've tried the blowdryer to heat the unit up before powering up. Monitor Succesfully powered up. I will need to retry this for a while b4 confirmation temperature affects monitor to startup. Preliminary Findings/Inconclusive
Attached Images
File Type: jpg IMG_20180706_133431.jpg (544.2 KB, 10 views)
File Type: jpg IMG_20180710_161827.jpg (736.3 KB, 13 views)
File Type: jpg IMG_20180710_161906.jpg (930.5 KB, 7 views)
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Old 07-11-2018, 04:35 PM   #2
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

You have a couple of voltage regulators with Vin, Adj & Vout pinout given. Have you checked the voltages.
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Old 07-11-2018, 07:56 PM   #3
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Hi, I'm a bit of a newb at this... haha. Willing to learn!

So, how does one check these voltages and what should I expect? Whats frustrating about the monitors issue is that whenever I take it apart it powers up fine, haha. So it's hard to nail down what's wrong with it whenever you try something on it.

Do you think it's not a capacitor issue? Since the thing is capable of powering up when it does?

Last edited by DaemonCross; 07-11-2018 at 09:13 PM..
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Old 07-12-2018, 03:31 AM   #4
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

From what you have just said , that it powers up when opened up, I would think you have bad solder joints. Inspect all your solder joints and on all the connector solder joints and make good.

Last edited by dick_barton; 07-12-2018 at 03:40 AM..
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Old 07-12-2018, 04:51 AM   #5
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Hi,

Just opened it back up and... I managed to have it show symptoms while it's taken apart. Judging from what I can tell. The LED Power Light Flicked once then shut-off followed by very faint buzzing(s) with a pulse around the area in red in general. And The Light Blue ones are (from how i hear it) possibly what's emanating (or affected by) the buzz. As moving my ear over each one you can hear the increase in tone as you hover over them. The Buzz goes away (Normal Operation) after one or a few attempts of unplugging and re-plugging.

I did notice that the Capacitor for the 5V (Higlighted in Green) shows 4.8v to 4.9v when in the buzzing + pulsing state. But when in normal operation it registers as 5.1v in both powered and standby. While the capacitor directly beside it is a steady 12v powered and standby.

Image Reference Link: https://imgur.com/a/PvuKlae


The (I assume) Power Regulators you mentioned.

Model No. M482 G1084 (Highlighted in Pink)
Standby Voltage - 1.2v (Both Legs)
Full-On Voltage - 1.24v (Both Legs)

Model No. 9997GH 11117H (Highlighted in Orange)
Standby Voltage - 12v (Both Legs)
Full-On Voltage - Right Leg - 12.32v
- Left Leg - 8.54v

I can provide you capacitor voltage readings (Standby/Full-On) if you want me to list them. But generally when in Full-On Status all capacitors "seems" to be generating appropriate voltages steadily (With LED Backlight). What do you think? Thanks!
Attached Images
File Type: jpg 0BA4czS.jpg (1.69 MB, 4 views)

Last edited by DaemonCross; 07-12-2018 at 05:09 AM.. Reason: Offsite image uploaded
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Old 07-12-2018, 05:11 AM   #6
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Quote:
Originally Posted by DaemonCross View Post
3. I've tried the blowdryer to heat the unit up before powering up. Monitor Succesfully powered up. I will need to retry this for a while b4 confirmation temperature affects monitor to startup. Preliminary Findings/Inconclusive
This points to the issue being with startup capacitors.
But as you mentioned you have an external power brick that should not be the case (startup cap will be in it)
So as dick_barton mentioned it might be more likely to be a bad solder joint or hairline PCB crack.
That said it wont hurt to replace those SMD electrlytic caps.
As from your other thread the caps are 2x 100F 16v and 1x 220F 16v.
But you should also understand that LOW ESR capacitors should be used.
What where the original through hole caps in the monitor and what did you replace them with?
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Old 07-12-2018, 05:58 AM   #7
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Hi,

Many thanks for the SMD Input, I badly needed that. It's crazy how the naming convention went south as far as SMD Caps goes. How hard is it to use v and uF right? haha.

I reckon going a bit higher in volts cap wise should be the same thing as with through-holes? As long as I keep within the right uF values right?

Uh... The caps that were originally there were...

TAICON C1113(M) 25v 220uf Replaced with PANASONIC EEU-FM1E221 25v 220uF

JAMICON 116C2(M) 100v 33uF Replaced with PANASONIC EEU-FC2A330 100v 33uF

*Crossfingers, ESR is low enough, haha.

So... What's that buzzing sound with a pulse I'm hearing? haha. I'm hoping that's just another symptom from a capacitor issue. Cuz all I have to work with is a regular soldering iron, I'm already iffy on how I'm gonna work those SMD caps, let alone those votlage regulators...

By any chance can I use the Through Hole 220uF 25vPanasonics I got for the 220uf 16v SMDs? Assuming I can work it to fit, haha.

Hopefully its not a hairline crack, haha. BTW Here's where I picked up the Hairdryer trick. Video Link -> https://www.youtube.com/watch?v=TXGxE9Fxhlw
I was hoping its the same thing for my caps...

Last edited by DaemonCross; 07-12-2018 at 06:06 AM.. Reason: Spelling
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Old 07-12-2018, 11:58 PM   #8
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Additional:

It seems the voltages on the regulator indicated in pink increase in value from 1.2v (Both Legs) to 2.1v Left Leg and 4.7v Right Leg. After re-flowing some capacitor and diodes.

Unfortunately Monitor still symptomatic. haha.
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Old 07-13-2018, 01:25 AM   #9
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

"Model No. 9997GH 11117H (Highlighted in Orange)
Standby Voltage - 12v (Both Legs)
Full-On Voltage - Right Leg - 12.32v
- Left Leg - 8.54v"

If you at the pin label: you see O (out), IN, and GND so GND pin should show 0V.
BTW, are those reading showing (-) number, I.E. - 12V, is that minus 12V or just 12V?
What is the DC output of that AC adapter, 12V?

"Model No. M482 G1084 (Highlighted in Pink)
Standby Voltage - 1.2v (Both Legs)
Full-On Voltage - 1.24v (Both Legs)"

That is adjustable regulator: you have IN, OUT (MIDDLE PIN/BIG TAB), ADJ. So I do not understand your description as to what the 'Both Legs' means.
You can tell that it is Adjustable regulator because it has two resistor network on the ADJ pin and the Output pin and GND. We need to readings of all 3 pins. It is G1084 series 5A Adjustable regulator.
http://pdf.dzsc.com/20090603/200903011947232880.pdf
http://www.gmt.com.tw/product/datasheet/EDS-1084.pdf

The inductor with blue top and has '4R7' on top looks to be for Buck converter, its output feed the IN pin of that LDO regulator marked in Pink.
So at this point we need verification of the Voltage readings.
Attached Files
File Type: pdf G_EDS-1084.pdf (29.6 KB, 2 views)
File Type: pdf G1084 ADJ.pdf (463.3 KB, 3 views)
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Basic LCD TV and Monitor troubleshooting guides.
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Inverter testing using old CFL:
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Last edited by budm; 07-13-2018 at 01:49 AM..
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Old 07-13-2018, 02:13 AM   #10
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Hi!

I'm very new at this and just learning along the way (Self-Youtube), haha. So I'm lacking with the tech jargons atm. By legs I mean the long legs I skipped the unsoldered short ones in the middle.

The Voltages for the 9997GH is (-)12v on Both Legs on Standby. (-)8.5v on the Left and (-)12.32v on the right when live.

As for the M482 it is (+)1.2v on the left and (+)1.2v on the right

Yes the DC Adapter Brick is 12v.

The 4r7, Buck you mentioned. By Memory (Not 100% sure) I think (I don't have the monitor with me atm) reads 5v (I'm not sure if I tested this right, I just stuck the black lead to ground and the positive lead to the 4r7's inside leg beside the capacitor). And the Dual Diode thing beside it is 12v.

And by "Both legs". I just tested it with the Negative lead on the large tab (the metal lip on top). And placing the positive leads on the legs that are soldered to the board which is the left and right ones (Viewed from the top with Square on top of legs). The middle one appears to be unsoldered and cut/short I may be mistaken, haha. I guess I messed that up? How do I properly test these?

Yes I did notice, after randomly re-flowing some suspicious looking joints. The M482 voltage readings shot up to (+)2.1v (Left) and (+)4.7v (Right). (Monitor still symptomatic)

Here are some additional screens of the regulators from my phone. The middle legs looks like they aren't mounted for some reason.

Thanks!



Last edited by DaemonCross; 07-13-2018 at 03:19 AM..
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Old 07-13-2018, 03:11 AM   #11
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Additional:

I did notice something peculiar. If you look at the image on the whole board. The IC's highlighted in blue on the far right, the bottom most one. When tested with a lead on the upper right leg in relation to the image.

Shows the voltage spike in tune with the pulsing in the buzz.

During Start-Up Failure it's spiking/pulsing 1.2v to 2.7v. When Monitor Functional/Powered On. It's 0v.

While the rest of the IC's highlighted in blue are a stable (+)4.7v.

Model No.
ATMLH110
02C M 6
0H2368K

The IC that's in tune with the pulsing is a different IC from those highlighted in blue.

I can't read the label clearly as someone left a silver ink blot on top of it. Partial read of it is...

Model No.
MXLC
****2026E
******-12G

Last edited by DaemonCross; 07-13-2018 at 03:58 AM..
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Old 07-13-2018, 10:41 AM   #12
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Additional #2:

The D2 and D3 Diodes leading to the Regulator Highlighted in Pink. Not sure if it's related but if memory serves right.

D2 101F SM340A = 4.9v
D3 101F SM340A = 4.6v

I'm just curious why they seem to be in the same line but D3 seems to have lost voltage?
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Old 07-13-2018, 10:41 AM   #13
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

The reading should not be showing minus (-) readings unless you have your meter probe reverse or using the the wrong GND point.
Please look at the spec sheet I provide so you can make the correct measurement of ALL 3 pins of the regulators. The measurement of all 3 legs are ref. to CIRCUIT GND, same for ALL other Voltage measurement.

Last edited by budm; 07-13-2018 at 10:43 AM..
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Old 07-14-2018, 05:58 AM   #14
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Alright! Will do!... When I get the time to go home I'll re-check them V's asap. Any other reading you need me to grab while I'm at it? Haha.

Last edited by DaemonCross; 07-14-2018 at 06:42 AM.. Reason: Grammar
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Old 07-20-2018, 05:31 AM   #15
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Ok, Update!

Sorry took a while, having a week of storm/hard rain (still ongoing) atm. Here are the readings of the 2 regulators.

I did 2 versions, One following this methodology. Link -> https://www.badcaps.net/forum/showthread.php?p=300999 (Option A)

And the other by placing the "Black/Com" lead on the GND labeled pin. (Option B)

-------------------------------------------------------------

Here are the results.

Option A. Black Lead/COM on Screw/PCB Mount

M482
G1084
Pin:

1 GND = (+) 2.12v
2 VO = (+) 3.37v
3 VI = (+) 4.62v

9997GH (Backlight FFC Cable connection with/without)
11117H
Pin:

1 GND = (+) 0v (w/out Backlight) | (+) 3.85v (w/Backlight)
2 IN = (+) 12.24v (w/out Backlight) | (+) 12.1v (w/Backlight)
3 O = (+) 0v (w/out Backlight) | (+) .1v (w/Backlight)


Option B: Black Lead/COM on GND

M482
G1084
Pin:

1 GND = Black Lead
2 VO = (+) 1.24v
3 VI = (+) 2.48v

9997GH (Backlight FFC Cable connection with/without)
11117H
Pin:

1 GND = Black Lead
2 IN = (+) 12v (On) (w/out Backlight) | (+) 8.24v (w/Backlight)
3 O = (+) 0v (On) (w/out Backlight) | (-) 3.7v (w/Backlight)

-------------------------------------------------------------

Now, Not sure why the 2 methods are giving me different results, haha (Forgive the Newbie). Sadly I couldn't induce the monitor to "fail to power-on" status. As the weather/temperature? does seem to matter of when it does fail. It's consistently powering up atm.

Last edited by DaemonCross; 07-20-2018 at 05:46 AM.. Reason: Formatting...
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Old 07-20-2018, 10:23 PM   #16
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Default Re: HP X2301 LED Backlight Monitor Power/Startup Issues

Option A. Black Lead/COM on Screw/PCB Mount

M482
G1084: This one is OK. 1.25V ref+ 2.12V on pin 1 = 3.37V
Pin:
1 GND = (+) 2.12v
2 VO = (+) 3.37v
3 VI = (+) 4.62v


9997GH (Backlight FFC Cable connection with/without)
11117H. This one is MOSFET AP9997GH, not regulator IC
Pin:
1 GND = (+) 0v (w/out Backlight) | (+) 3.85v (w/Backlight)
2 IN = (+) 12.24v (w/out Backlight) | (+) 12.1v (w/Backlight)
3 O = (+) 0v (w/out Backlight) | (+) .1v (w/Backlight)

1) Please check the Voltage between point A and point when monitor is OFF and when you turn on the monitor, you will need to leave the probes on both legs while you are doing the test.
2) You need to check the Voltages on all 3 pin of the regulator IC U3 and TU5 as in option A.
Attached Images
File Type: jpg Voltages check.jpg (679.5 KB, 6 views)
Attached Files
File Type: pdf AP9997gh-hf.pdf (97.3 KB, 3 views)

Last edited by budm; 07-20-2018 at 10:24 PM..
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