Author Topic: LCD Monitor has rough screen with ripples  (Read 3751 times)

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Offline rockblues

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LCD Monitor has rough screen with ripples
« on: August 18, 2019, 03:01:58 pm »
Hi. Dell SE2717H wouldn't turn on. Vertical scratchy lines flowing down. Black screen. Ordered replacement caps Radio Shack 470uF 35v to replace 470uF 25v. The Radio Shack 220uF 35v cap has leads out of both ends. Can't use. Replaced all three 470uF caps. Hooked up monitor to my PC. Desktop Blue screen. Descending horizontal ripple flowing lines.  Replaced the 220uF 25v cap with a 470uF 35v. Same Desktop Blue screen. Very scratchy and descending horizontal ripple flowing lines. Ordered a power board from Ebay from a monitor with a cracked screen. How come the cap replacement didn't work? Thanks.
« Last Edit: August 18, 2019, 03:11:10 pm by rockblues »
 

Offline Rasz

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Re: LCD Monitor has rough screen with ripples
« Reply #1 on: August 18, 2019, 09:34:44 pm »
waste of money :(
this is bad glass, or best case scenario bad tcon/ribbon connection. You lost vertical sync bit somewhere.

> Desktop Blue screen

it should be blue :) thats default win10 wallpaper
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Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #2 on: August 18, 2019, 09:40:36 pm »
Yeah, most likely dead panel. On top of that replacement capacitors are completely unsuitable for the job. They will fail in a few months maximum.
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #3 on: August 18, 2019, 09:58:16 pm »
waste of money :(
this is bad glass, or best case scenario bad tcon/ribbon connection. You lost vertical sync bit somewhere.
> Desktop Blue screen
it should be blue :) thats default win10 wallpaper

Bad LCD? Thanks!! What is tcon/ribbon connection?
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #4 on: August 18, 2019, 10:01:36 pm »
Yeah, most likely dead panel. On top of that replacement capacitors are completely unsuitable for the job. They will fail in a few months maximum.

Thanks. Asking to learn. What caps do you use? These are Radio Shack capacitors. How come they're completely unsuitable for the job?
 

Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #5 on: August 18, 2019, 10:10:06 pm »
Yeah, most likely dead panel. On top of that replacement capacitors are completely unsuitable for the job. They will fail in a few months maximum.

Thanks. Asking to learn. What caps do you use? These are Radio Shack capacitors. How come they're completely unsuitable for the job?
There should be LOW ESR capacitors rated for high ripple current. But you used general purpose capacitors, on top of that rated only for 85oC temperature. They will simply fail in short time unable to survive high stress.
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #6 on: August 18, 2019, 10:11:37 pm »
Yeah, most likely dead panel. On top of that replacement capacitors are completely unsuitable for the job. They will fail in a few months maximum.

Thanks. Asking to learn. What caps do you use? These are Radio Shack capacitors. How come they're completely unsuitable for the job?
There should be LOW ESR capacitors rated for high ripple current. But you used general purpose capacitors, on top of that rated only for 85oC temperature.

Appreciate this. No ESR info at Radio Shack. What caps do you recommend? Panasonic from Mouser? What about using 35V instead of 25 V?
« Last Edit: August 18, 2019, 10:13:17 pm by rockblues »
 

Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #7 on: August 18, 2019, 10:21:56 pm »
Yeah, most likely dead panel. On top of that replacement capacitors are completely unsuitable for the job. They will fail in a few months maximum.

Thanks. Asking to learn. What caps do you use? These are Radio Shack capacitors. How come they're completely unsuitable for the job?
There should be LOW ESR capacitors rated for high ripple current. But you used general purpose capacitors, on top of that rated only for 85oC temperature.

Appreciate this. No ESR info at Radio Shack. What caps do you recommend? Panasonic from Mouser? What about using 35V instead of 25 V?
You should find datasheet for original capacitors and find replacement with ESR and ripple current spec not lower than original. Not that they are the problem with this monitor to begin with. If you somehow manage to fix it, returning original capacitors back probably would be the best solution. I don't think radioshack stocks any decent LOW ESR capacitors. And you don't need any info from radioshack, just google for a datasheet.
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #8 on: August 18, 2019, 11:04:58 pm »
Very hard to find an ESR datasheet for SE2717H Caps. Did find this - ESR Monitor that determines if a cap is bad!!!! - Without removing it from the board!

The writer found a bad cap on the SMALLER board. Replacing this fixed his Monitor.
http://www.bot-thoughts.com/2010/01/esr-test-harness-part-2.html

Equivalent Series Resistance Meter!!!! (from Part 2 - Testing Capacitors - Link: From Powell's website on ESR measurement
http://www.ludens.cl/Electron/esr/esr.html

BTW - what do you know about vertical sync?  tcon/ribbon connections?
« Last Edit: August 18, 2019, 11:16:38 pm by rockblues »
 

Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #9 on: August 18, 2019, 11:11:44 pm »
Very hard to find an ESR datasheet for SE2717H Caps. Did find this - ESR Monitor that determines if a cap is bad!!!!
You should google capacitor brand and series. Not SE2717H  :palm:.
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #10 on: August 18, 2019, 11:15:30 pm »
Very hard to find an ESR datasheet for SE2717H Caps. Did find this - ESR Monitor that determines if a cap is bad!!!!
You should google capacitor brand and series. Not SE2717H  :palm:.

OK - Capacitor tier list - https://www.tomshardware.com/reviews/power-supplies-101,4193-5.html

Quote
First-Tier Caps
Even the Japanese manufacturers include some mainstream lines in their portfolios, which aren't as good as their top-of-the-line products. So, in addition to the brand, we always take a closer look at the product family and its specifications to better judge capacitor quality and to make a rough estimation of their lifetime.

All Japanese caps are considered of high quality, and we like to see the following cap brands:

Rubycon
United Chemi-Con (or Nippon Chemi-Con)
Nichicon
Sanyo/Suncon
Panasonic
Hitachi
FPCAP or Functional Polymer Capacitor (ex-Fujitsu caps segment, which was bought by Nichicon)
ELNA
Besides Japanese manufacturers there are also several US and European vendors that make high-quality capacitors. Probably we won't meet any of the below cap brands inside a consumer grade PSU, at least their electrolytic offerings, but we decided that it still worth mentioning them.

Cornell Dubilier (USA)
Illinois Capacitor (Currently owned my Cornell Dubilier)
Kemet Corporation (USA)
Vishay (USA)
EPCOS (TDK company, Germany)
W├╝rth Elektronik (Germany)




« Last Edit: August 18, 2019, 11:38:45 pm by rockblues »
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #11 on: August 18, 2019, 11:41:10 pm »
Ahhhhh!!! Searched Mouser - Panasonic 470uF 25V LOW ESR capacitors - now must check: Height - Width - Spacing!!!!

Orig 470uF 25V cap from Dell : 12mm Height - 10mm Width - 5mm Spacing

Mouser : Choice 01
https://www.mouser.com/ProductDetail/Panasonic/EEU-FM1E471LB?qs=sGAEpiMZZMukHu%252BjC5l7YZoqau5lHLGPo6O6lmioLMI%3D

Manufacturer: Panasonic
Product Category: Aluminum Electrolytic Capacitors - Radial Leaded
RoHS:  Details 
Product: Low Impedance Electrolytic Capacitors
Termination Style: Radial
Capacitance: 470 uF
Voltage Rating DC: 25 VDC

Tolerance: 20 %
Ripple Current: 1.56 A
Minimum Operating Temperature: - 40 C
Maximum Operating Temperature: + 105 C
Diameter: 8 mm
Length: 20 mm

Lead Spacing: 5 mm
Lead Style: Straight
Life: 4000 Hour
Series: FM
Packaging: Cut Tape
Packaging: Reel
Type: Low Impedance Radial Leaded Aluminum Electrolytic Capacitor 
Brand: Panasonic 
Product Type: Electrolytic Capacitors

Mouser : Choice 02
https://www.mouser.com/ProductDetail/Panasonic/EEU-FM1E471B?qs=sGAEpiMZZMukHu%252BjC5l7YZoqau5lHLGPkqlp52X42jo%3D

Product Category: Aluminum Electrolytic Capacitors - Radial Leaded
RoHS:  Details 
Product: Low Impedance Electrolytic Capacitors
Termination Style: Radial
Capacitance: 470 uF
Voltage Rating DC: 25 VDC

Tolerance: 20 %
Ripple Current: 1.79 A
Minimum Operating Temperature: - 40 C
Maximum Operating Temperature: + 105 C
Diameter: 10 mm
Length: 16 mm

Lead Spacing: 5 mm
Lead Style: Straight
Life: 4000 Hour
Series: FM
Packaging: Cut Tape
Packaging: Reel
Type: Low Impedance Radial Leaded Aluminum Electrolytic Capacitor 
Brand: Panasonic 
Leakage Current: 117.5 uA
« Last Edit: August 18, 2019, 11:43:43 pm by rockblues »
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #12 on: August 18, 2019, 11:51:46 pm »
Good Article on Ripple Current
https://passive-components.eu/ripple-current-and-its-effects-on-the-performance-of-capacitors/


https://forum.allaboutcircuits.com/threads/rated-ripple-current.17346/

Quote from: mik3
The rated ripple current of a capacitor is fixed and is the amount of current the capacitor can conduct without get destroyed (overheat). The greater the rated ripple current the more current the capacitor can conduct. It is a fixed value but the current in the circuit, where you will use the capacitor, depends upon the frequency and the voltage.

You have to use a capacitor with a rated ripple current equal or greater than the ripple current the design is calculated to produce.
« Last Edit: August 18, 2019, 11:56:55 pm by rockblues »
 

Online mariush

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Re: LCD Monitor has rough screen with ripples
« Reply #13 on: August 18, 2019, 11:52:35 pm »
Capacitor maker and series is most of the time written on capacitor.
In the case of your Radioshack capacitors, the logo tells you they're made by Lelon and then the next text tells you the series and temperature ... REA and 85c
The other visible row of text will often be 4 numbers (week and year of manufacture) or some other code (batch of production etc)

If you look up Lelon REA you find datasheet easily : http://www.lelon.com.tw/upload/prod/154355894364.pdf
You can see it says "Standard series for general purpose" - the voltage rating alone would tell you these capacitors are just... average

You're dealing with a switching power supply, and majority of switching power supplies require LOW ESR capacitors, rated for 105c (or more, but 105c is enough)

IN this application ESR is pretty much the same as impedance - you won't find esr but you'll find impedance at 100kHz and that's what you use.

Your original capacitors are probably made by Samsung, Samwha, Su's'con or other chinese/taiwanese brands.

You need to replace original capacitors with ones that
match or exceed the voltage rating - keep in mind of diameter and height you can have
match the capacitance (in lots of situations it's safe to go next step up, capacitance + 10-20%)
get impedance at 100kHz value as close as possible to the original or a bit lower - it's ok if it's let's say 5-10% higher, and let's say up to 20-30% lower... but don't try to get absolute lowest values... sometimes the circuit can be affected if you use too good capacitors.
get current ripple value as close as possible or higher ... let's say 10% less is still acceptable, but equal or higher is recommended.

Anyway don't stress too much about it, your failure is most likely not capacitor related and harder to solve.
 

Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #14 on: August 18, 2019, 11:53:00 pm »
Very hard to find an ESR datasheet for SE2717H Caps. Did find this - ESR Monitor that determines if a cap is bad!!!!
You should google capacitor brand and series. Not SE2717H  :palm:.

OK - Capacitor tier list - https://www.tomshardware.com/reviews/power-supplies-101,4193-5.html
I mean capacitors which were originally there, not some tier list. For example you bought Lelon REA http://www.lelon.com.tw/upload/prod/154355894364.pdf
But as already said, don't bother because problem is not in capacitors and this monitor is beyond economical repair with 95% probability.
« Last Edit: August 18, 2019, 11:55:01 pm by wraper »
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #15 on: August 19, 2019, 12:08:40 am »
These are the Dell SE2717H caps on the Larger power board.

Larger Power Supply Board
220uF = Elite
470uF = Hermei

Smaller Power Supply Board
XL 100 ETZ
« Last Edit: August 19, 2019, 01:13:13 am by rockblues »
 

Online mariush

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Re: LCD Monitor has rough screen with ripples
« Reply #16 on: August 19, 2019, 12:28:28 am »
Elite EG series : http://www.paullinebarger.net/DS/Elite/Elite%20[radial%20thru-hole]%20EG%20Series.pdf

220uF 25v :  0.13 ohm esr , 640 mA ripple current

Hermei LS series : http://www.paullinebarger.net/DS/Hermei/Hermei%20%5Bradial%20thru-hole%5D%20LS%20Series.pdf

470 uF 25v ; not in datasheet, either custom order or the datasheet above is older revision
If you use the 560uF values, it's 0.036 ohm esr and 1140mA ripple

The panasonic fm series has these

220/25 ; 950mA (higher, ok)   0.056 (a bit too low, but here it would probably be fine)
470/25 :

  8x20 1560 (higher so ok)  0.030 (lower, so ok, close enough to estimated esr of original to not be a concern)
10x16 1790   0.026 (same deal, both parameters good)

so FM series would be suitable to replace both
 

Offline wraper

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Re: LCD Monitor has rough screen with ripples
« Reply #17 on: August 19, 2019, 12:28:41 am »
http://www.paullinebarger.net/DS/Elite/Elite%20%5Bradial%20thru-hole%5D%20EG%20Series.pdf
http://www.paullinebarger.net/DS/Hermei/Hermei%20%5Bradial%20thru-hole%5D%20LS%20Series.pdf
They are not bulged so it's unlikely there is anything wrong with them. Also symptoms of the fault has nothing to do with bad capacitors. Replacing them is just a waste of money.
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #18 on: August 19, 2019, 01:20:01 am »
mariush and wraper - This is incredible!!! You are both amazing!!!!

Have a better understanding of what is what. Possibly the replacement of both power boards / cables might do the job. If not it's the LCD glass.

On order = replacement boards / cables form a new Dell SE2717H nonitor that had a cracked screen / shipping. Will arrive later this week - will keep you both posted!!!!

Huge thanks!!!!!   :clap: :clap: (other option is DARPA mental telepathy to make all work - not gonna happen outside their gates)
« Last Edit: August 19, 2019, 05:51:00 am by rockblues »
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #19 on: August 19, 2019, 03:09:16 am »
HOW TO SOLVE HORIZONTAL LINE PROBLEM IN LCD - LED TV.-- TECH PRABU -- EXP IN TAMIL - YouTube


Cleaned all cables - Still lines!!
 

Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #20 on: August 19, 2019, 03:14:02 am »
Lines on Monitor Screen (power applied - not connected to PC)

What causes these broken lines?
« Last Edit: August 19, 2019, 03:15:39 am by rockblues »
 

Offline Rasz

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Re: LCD Monitor has rough screen with ripples
« Reply #21 on: August 19, 2019, 07:22:09 am »
HOW TO SOLVE HORIZONTAL LINE PROBLEM IN LCD - LED TV.-- TECH PRABU -- EXP IN TAMIL - YouTube

you dont have horizontal lines, you are missing vertical sync or vertical address decoder/adder is broken resulting in some lines landing in wrong places/not being displayed at all


On order = replacement boards / cables form a new Dell SE2717H nonitor that had a cracked screen / shipping. Will arrive later this week - will keep you both posted!!!!

too bad you didnt order the only board that actually mattered, the TCON, small board mounted directly on the lcd panel itself
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Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #22 on: August 21, 2019, 04:55:32 pm »
HOW TO SOLVE HORIZONTAL LINE PROBLEM IN LCD - LED TV.-- TECH PRABU -- EXP IN TAMIL - YouTube
you dont have horizontal lines, you are missing vertical sync or vertical address decoder/adder is broken resulting in some lines landing in wrong places/not being displayed at all

On order = replacement boards / cables form a new Dell SE2717H nonitor that had a cracked screen / shipping. Will arrive later this week - will keep you both posted!!!!

too bad you didn't order the only board that actually mattered, the TCON, small board mounted directly on the lcd panel itself

- missing vertical sync or vertical address decoder/adder is broken - very cool info!!! wow!! New to all this. Glad to get insights. Thanks!!

Researched TCon - Google -

lcd tv repair basic
http://www.electronicrepairguide.com/lcd-tv-repair-basic.html

Shop Jimmy - TCon Boards - CMO 35-D026047 (V400H1-C03) T-Con Board Component Repair Kit
ttps://www.shopjimmy.com/cmo-35-d026047-t-con-board-component-repair-kit.htm

Ebay Search : 715G8429-M01-000-0H4T (Code on Smaller Board - Monitor SE2717H)

Earlier, ordered replacement boards cables Don't see how I can replace just the TCON chip itself. A complete set of boards / cables for SE2717H that will arrive Friday.
Will replace the smaller board with new TCon chip, and hopefully all will be fine. Stay tuned. Thanks again!!




« Last Edit: August 21, 2019, 05:50:12 pm by rockblues »
 

Offline Rasz

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Re: LCD Monitor has rough screen with ripples
« Reply #23 on: August 21, 2019, 06:21:17 pm »
you can see that you have proper picture, default w10 wallpaper, but in two copies interleaved at two different vertical offsets, thats why I think something is wrong with tcon-glass connection

Will replace the smaller board with new TCon chip, and hopefully all will be fine. Stay tuned. Thanks again!!

"Tcon" (Timing Controller) is a small board on the back of panel itself, sometimes even permanently attached to it. Its role is to deserialize incoming digital picture data and drive the panel horizontal/vertical buffers. You didnt order one,  'Ebay Parts 01.png' shows power supply and so called 'Scaler Board', those are >99% useless in your case.
quick google http://monitorinsider.com/monitor_anatomy/ has usable writeup
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Offline rockblues

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Re: LCD Monitor has rough screen with ripples
« Reply #24 on: August 21, 2019, 06:48:57 pm »
you can see that you have proper picture, default w10 wallpaper, but in two copies interleaved at two different vertical offsets, thats why I think something is wrong with tcon-glass connection

Will replace the smaller board with new TCon chip, and hopefully all will be fine. Stay tuned. Thanks again!!

"Tcon" (Timing Controller) is a small board on the back of panel itself, sometimes even permanently attached to it. Its role is to deserialize incoming digital picture data and drive the panel horizontal/vertical buffers. You didnt order one,  'Ebay Parts 01.png' shows power supply and so called 'Scaler Board', those are >99% useless in your case.
quick google http://monitorinsider.com/monitor_anatomy/ has usable writeup

Parts -
Monitor = LCD glass (no TCon Board on the back)
Plastic frame
Cables
Larger Power board
Smaller main board - VDA / HDMI ports

No separate TCon Board - unless it's on one of these two boards. Don't see a TCon type chip. Where do you think it may be? Thanks!

Very possible that the HDMI port was injured on the monitor. If true, the replacement small board (arriving Fri / Sat) will fix this vertical screen situation.
« Last Edit: August 22, 2019, 02:18:52 am by rockblues »
 


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