Author Topic: Bad Caps in Monitor? (Read 20627 times)

Zopsi · « **on:** May 31, 2012, 02:24:49 am »

Anyone have any experience replacing bad caps in monitors/tvs? My HP ZR2740W is acting up as of last night for the second time and HP doesn't want to replace it again. It will go black and come back on every so often (tested to make sure it wasn't graphics card).

Thanks guys.

Dark Prognosis · « **Reply #1 on:** May 31, 2012, 02:58:57 am »

My Samsung 215TW is notorious for bad caps and they are the same ones too. Opened mine up and almost all of them had vented so were bulging.

Look to your electrolytic caps for buldging/venting, etc... as they are normally the ones that go bad cause the bastard LCD companies charge 600 dollars (like mine) then fill them with One Hung Lo pieces of crap.

DrGeoff · « **Reply #2 on:** May 31, 2012, 03:06:14 am »

Samsung are notorious for this problem, in both LCD TV's and monitors.

http://www.axtsystems.com/index.php?option=com_content&view=article&id=83:samsung931bfix&catid=48:fixingstuff&Itemid=81

Zopsi · « **Reply #3 on:** May 31, 2012, 03:11:02 am »

Makes me angry this monitor was slightly less than $800 when I bought it. I'll have a look tomorrow and see what I can do.

mariush · « **Reply #4 on:** May 31, 2012, 03:16:17 am »

If you don't see something obvious, register on the badcaps.net forums and post pictures in the "Monitors" section and people there will try to help you.

I personally fixed several monitors, mostly with bad caps or old cfl lamps..

Zopsi · « **Reply #5 on:** May 31, 2012, 03:19:16 am »

It is an LED backlit IPS Monitor and the backlight seems to be functioning so it is likely the caps. Thanks for the heads up about the website.

Mint. · « **Reply #6 on:** May 31, 2012, 03:33:04 am »

I have the same problem. I am not sure whenever I should open up the monitor and replace the caps...

Zopsi · « **Reply #7 on:** May 31, 2012, 03:39:24 am »

Same monitor or different monitor same problem?

Mint. · « **Reply #8 on:** May 31, 2012, 03:56:19 am »

Samsung monitor and similar problem. The monitor usually makes a low volume high pitched sound when on and sometimes gives me a black screen.

DrGeoff · « **Reply #9 on:** May 31, 2012, 04:02:53 am »

Sounds just like bad caps. I think they buy their PSU modules from Wun-Hung, and there is definitely a quality problem. I have often found 10V electros on 12V rails in these modules.

Mint. · « **Reply #10 on:** May 31, 2012, 04:07:52 am »

Quote from: DrGeoff on May 31, 2012, 04:02:53 am

Sounds just like bad caps. I think they buy their PSU modules from Wun-Hung, and there is definitely a quality problem. I have often found 10V electros on 12V rails in these modules.

What is ironic is the fact that those monitors usually cost over $300!

DrGeoff · « **Reply #11 on:** May 31, 2012, 04:14:41 am »

You can get them cheaper than that! After the caps blow, the punters usually chuck them out! Then it's a $5 fix and you have a good working monitor (or TV).

T4P · « **Reply #12 on:** May 31, 2012, 04:14:57 pm »

Quote from: Dark Prognosis on May 31, 2012, 02:58:57 am

My Samsung 215TW is notorious for bad caps and they are the same ones too. Opened mine up and almost all of them had vented so were bulging.

Look to your electrolytic caps for buldging/venting, etc... as they are normally the ones that go bad cause the bastard LCD companies charge 600 dollars (like mine) then fill them with One Hung Lo pieces of crap.

... Samsung is basically One Hung Low... Everything from them is from china now, anyways, most koreans are exactly that, communists.

I have lots of rant but i cannot complain about the good old days of samsung (my screen is still good after about 4-5 years)

tom66 · « **Reply #13 on:** May 31, 2012, 04:25:14 pm »

Quote from: DaveXRQ on May 31, 2012, 04:14:57 pm

Quote from: Dark Prognosis on May 31, 2012, 02:58:57 am
My Samsung 215TW is notorious for bad caps and they are the same ones too. Opened mine up and almost all of them had vented so were bulging.

Look to your electrolytic caps for buldging/venting, etc... as they are normally the ones that go bad cause the bastard LCD companies charge 600 dollars (like mine) then fill them with One Hung Lo pieces of crap.
... Samsung is basically One Hung Low... Everything from them is from china now, anyways, most koreans are exactly that, communists.

I have lots of rant but i cannot complain about the good old days of samsung (my screen is still good after about 4-5 years)

Agreed - Samsung TVs are designed fairly well, but they skimp on parts. I've repaired more Samsung TVs than any other brand (five in total.) Newer Samsung TVs are using crap CMO and Chungwha LCD panels which develop dark spots after a year or so and make LCDs look bad for motion performance. (People complain LCDs blur a lot, but only the cheap ones - Samsung and LG Philips/LG Display panels seem pretty good to me.)

SeanB · « **Reply #14 on:** May 31, 2012, 04:34:18 pm »

Samsung monitors were very good, never had one fail in the warranty period, but all would die a spectacular death from LOPT failure after the warranty period was up ( 5 years on the LOPT and tube) but even those driven 24/7 for 5 years had good tubes up to the tip. The caps would be bulging, brown and dying, but the design still ran, but the transformers were not available.

Don't know about newer stuff, touching wood about my monitor...........

Zopsi · « **Reply #15 on:** May 31, 2012, 05:16:58 pm »

I have 4 samsung LCD's and they all work brilliantly one of them is like 5-6 years old. Same with the Dell monitors I own. However the 2 HP monitors I have had fail constantly.

AlphZeta · « **Reply #16 on:** May 31, 2012, 05:41:41 pm »

I just fixed an LCD of similar problems for a co-worker a few months ago. The monitor would not come on and after opening in up, it appeared that one of the cap in the switching power supply went bad (has white residue on it). After I replaced the cap, everything worked again.

Zopsi · « **Reply #17 on:** May 31, 2012, 05:55:36 pm »

I'm doing that today. I'll let you guys know.

SeanB · « **Reply #18 on:** May 31, 2012, 06:21:12 pm »

That is why i have a container with assorted SMPS capacitor replacements in it. A few 47/400V units, a few 1000/25V units, some 470/25V and a few 100/16v units at last look. Pretty much covers most values more or less in all I encounter. Generally you can replace with whatever is a higher voltage and where the capacitance is close ( within 30% or so) and which will fit in the allocated space on the PCB.

Zopsi · « **Reply #19 on:** May 31, 2012, 07:05:46 pm »

I posted a video of the problem http://youtu.be/JsVdwXGSOjk. Looks like it is caps to me, but I want to get a second opinion. I found someone willing at HP to consider giving me a replacement, but the last time they replaced it I had to go through 4 crappy monitors that were obviously cosmetically damaged before I got a good one (Pic of one: http://zopsi.com/broken.jpg). Needless to say I would rather repair it myself if it is the caps than go through that crap.

Mashpriborintorg · « **Reply #20 on:** May 31, 2012, 07:12:07 pm »

I've found a 21 inch Samsung TFT monitor abandonned in the street last week. Nice body condition, but would not power up. 20 minutes of work and 3 capacitors later, it was installed and working onto my desk. I did only replace the worst looking capacitors, with what I had in stock, it seems to be enough for now. If it fails again, I'll just have to replace all the remaining original caps. Not a bad deal.

T4P · « **Reply #21 on:** May 31, 2012, 07:12:54 pm »

Quote from: SeanB on May 31, 2012, 06:21:12 pm

That is why i have a container with assorted SMPS capacitor replacements in it. A few 47/400V units, a few 1000/25V units, some 470/25V and a few 100/16v units at last look. Pretty much covers most values more or less in all I encounter. Generally you can replace with whatever is a higher voltage and where the capacitance is close ( within 30% or so) and which will fit in the allocated space on the PCB.

Ah. Nice, added these caps to my order

Zopsi · « **Reply #22 on:** May 31, 2012, 07:15:25 pm »

Anyone take a look at that video?

SeanB · « **Reply #23 on:** May 31, 2012, 07:24:09 pm »

Dave, just make sure they are 105C low ESR units, with a high ripple current rating, preferably with a spec that includes a ESR at 10kHz and 100kHz. Best to get a few footprints as well, you will need them in various lead spacings to suit various boards. Best to include a few 2200/16 units as well, and some 2200/10 units. Do not bother with any 6.3V units as they are pretty much the same size as 10V units.

FenderBender · « **Reply #24 on:** May 31, 2012, 08:05:18 pm »

Hmm as far as I remember, Samsung was one of the best, if not THE best manufacturer of monitors and LCD panels. I think their technology is still good, just shitty quality control and poor component selection. For monitors, you really need to use good quality components, since the temperatures they are subjected to. 105*C caps are a must and of a good manufacturer. Otherwise you are just asking for trouble.


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Author Topic: Bad Caps in Monitor? (Read 20627 times)

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