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Samsung Syncmaster 245BW
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Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Samsung Syncmaster 245BW
OK - this is a bit of a different post as I'm not a hobbyist - I've actually designed some SPS(Switching Power Supplies). So I figured I would leave a few notes that might help you guys out.
First, The problem with the 68ohm resistors probably wasn't due to the engineer - some idiot thought they were improving reliability by globing the glue on them. The problem is that the resistors power dissipation is rated in free air - not insulated with glue. This means that the advice to remove the glue from these and the other power resistors is correct and important.
Second - I fixed two of these - both had bad CM802 capacitors. This capacitor is a low enough value that most ESR meters won't see it - but this cap needs to be in good shape.
Third, I used a Capwizard ESR meter - https://secure.transtronics.com/CAP-WIZARD.htm
(full disclosure - my company sells these - but I'm sure others would work). This meter allows me to test the caps mostly in circuit and I have a list of the ones I replaced below. There is a beeper so I don't have to look at the meter.
Fourth, - Probably not a good idea just to use any cap - SPS use 'low ESR' caps and depending on where in the circuit they may have special ratings. Why this is important is that the higher the ESR the more it produces heat and heat kills caps.
Fifth - Just as a review of the design - this board should have been two sided - it would have made it more reliable and help dissipate heat. That the caps are failing at such a high rate means they were under specified. For the price of these monitors, they should have provided better quality.
Parts replaced due to bad ESR: (Someone should go through this thread and count the times for each cap changed that fixed things)-
CM802 (both boards)
CM810 (both boards)
CP811 (both boards)
CB808
CB872
CB806
CB810 (both boards)
68ohm resistors only two - but on the same board.
They really should have specified LESR caps or bigger ones.. Design target was probably for a 2 year life span to losing 5% - Creeps - probably saved $2/board.
I bought a cap kit off Amazon - it allowed me to fix two power supplies, except it was missing the CM802 capacitors and I would probably use better parts next time.
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Re: Samsung Syncmaster 245BW
What type of cap did you use for CM802 (18nF 630V)?Last edited by budm; 09-15-2014, 05:30 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Samsung Syncmaster 245BW
Originally posted by budm View PostWhat type of cap did you use for CM802 (18nF 630V)?
Digikey - P15435-ND
Designed for high frequency and pulse applications.
•Low loss
Should work here - pretty good dissipation factor. There might be something better out there - didn't look that far. This is in the current path - needs to be a good cap.
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Re: Samsung Syncmaster 245BW
That is the series of the cap I recommend people to use for replacement. EPCOS is also good.
That same drive setup is also used in a lot of SAMSUNG PS for TVs.Last edited by budm; 09-15-2014, 10:22 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Samsung Syncmaster 245BW
Originally posted by budm View PostThat is the series of the cap I recommend people to use for replacement.
That same drive setup is also used in a lot of SAMSUNG PS for TVs.
I have 8 of these total - or I wouldn't have bothered learning how to fix them. These were the best monitors in their class when they were new - today everything is 1080I. I've was thinking of getting some 4K TV sets - 39" for $339 - the reviews are saying the power supplies go out sometimes in just a few hours...so.. Plan to keep these working for a few years until they get the bugs out and the price down on the 4K products.
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Re: Samsung Syncmaster 245BW
Originally posted by sky007 View PostI get little progress. I put back QB801, and open JB805 which feed M_vcc to IC801S (SMPS IC), break the connect J808 which feed M_Vcc to ICM801, then between the primary ground and the QB801 Emitter read 7.2k Ohm, the voltage on Emitter is 17.56V now.
If one of jumpers connect, I would not get 17.56V on QB801.
Is it possible the IC801S and ICM801 both blow out?
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Re: Samsung Syncmaster 245BW
Originally posted by xtronics View PostOK - this is a bit of a different post as I'm not a hobbyist - I've actually designed some SPS(Switching Power Supplies). So I figured I would leave a few notes that might help you guys out.
Talking from own experience, I've been trying to fix one from a failed HM2493 the last few weeks. I have a working 195A here as well, and think I have found all failed components by now. I'm getting ready to order replacement components... After that I have to fix the T-con as well (gives a white screen, although the fuse is intact).
re-atariLast edited by re-atari; 10-01-2014, 04:35 PM.
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Re: Samsung Syncmaster 245BW
-195A is what sky007 is working on. It is also known for bad brown glue:
https://www.badcaps.net/forum/showthread.php?t=34692Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Samsung Syncmaster 245BW
Originally posted by budm View Post-195A is what sky007 is working on. It is also known for bad brown glue:
https://www.badcaps.net/forum/showthread.php?t=34692
BTW: the glue on both PCB's was still yellow and sticky, nowhere baked into the conductive brown or even black conductive hardened mess I saw on photos in other threads.
I checked the components underneath the glue on the defective PCB afterwards, and they were all OK. The fault appears to lie on the underside of the PCB in a couple of smd components. I already replaced the infamous (always failing) 100R resistor (was open circuit), but think the 27V zener and PNP transistor alongside it will need replacing as well. And I have another suspect component in sight.
I'm thinking of temporarily replacing them with standard through-hole components for testing purposes. I can buy these at a local electronics shop, and want to avoid ordering these smd components without necessity.
re-atariLast edited by re-atari; 10-02-2014, 07:25 AM.
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Re: Samsung Syncmaster 245BW
is this a suitable replacement for the RM801 fusible resistor on the bn44-00195a
http://www.maplin.co.uk/p/wirewound-...resistor-w0.22
its a different type of resistor that instead of being rated at 1w its at 3w
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Re: Samsung Syncmaster 245BW
I have just replaced the resistor with a 1w 0.22 ohm one, the monitor is getting further now, so it doesnt automatically go into standby, instead the power light is constantly on, with or without being connected to a PC.
The PC is recognizing the monitor too (not sure if it was before) I have also tried shining a light on the screen to see if it was the backlight and I can't see anything (it wouldn't explain the power light being constantly on with no input though)
also no blowups or sparks so thats also a plus
I am going to recheck all the wires to make sure they are all firmly connected inside however if anyone has advice at this point that would be great
P.S.
The power button turns on and off so thats working tooLast edited by SJones88; 10-13-2014, 02:20 PM.
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Re: Samsung Syncmaster 245BW
My Samsung 245B's screen (LTM240M2) is now slowly dying
after a drink was spilled on it
But it would seem several other monitors also use the same part:
-Dell 2407WFP
-HP LP2465
-Samsung 244T, 245T, 245BW and more
-BenQ FP241W (?)
-NEC LCD2470WNX (?)
My question is:
Can I just buy any of those monitors and swap the screen, or are there OTHER SPECIFICATIONS to consider?Last edited by denizen54; 04-17-2016, 01:36 PM.
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Re: Samsung Syncmaster 245BW
Originally posted by denizen54 View PostAlso, the sticker on the back says: LTM240CT01
Is this always the same part?Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
Comment
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Re: Samsung Syncmaster 245BW
http://www.beyondinfinite.com/library.html
Just do the search on those numbers to see what you come up with.
You can look up the spec sheet to see what they are.
Look at EBAY for the replacement, may be cheaper to get used one from local recycle.Last edited by budm; 04-17-2016, 10:31 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Samsung Syncmaster 245BW
Okay, I just replaced the screen, but the new one seems to be slightly darker at the top.
This effect isn't extremely strong, but it bothers me nonetheless.
I tried displaying solid (R,G,B) rectangles full screen and it does this with any color.
The previous screen (the now broken one) didn't have this issue.
Is there a way to fix this?Last edited by denizen54; 04-25-2016, 06:02 PM.
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Re: Samsung Syncmaster 245BW
I've tested the screen with another identical monitor's power supply and inverter assembly, and the screen has exactly the same problem.
So it's the screen itself which has a uniformity issue for brightness.
Does the logic board on the back of the screen(240CT01C2L) regulate the voltage on the screen surface?
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