Re: Syncmaster T190 - a headache
Hi,
Have you found a solution to the problem ? I am not sure the PS is at fault here.
Can you insert 5V from another source (like a bench power supply) into the main board, (monitor''s PS disconnected) and check again the voltage at the local regulators, memory IC's and if the 5V DC is present at the LVDS (CN400 )cable, pins 1 and 7 ?
addytzu123
Senior Member
Last Activity: 05-19-2024, 03:53 AM
Joined: 03-28-2013
Location: IASI
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Re: Syncmaster T190 - a headache
See also the wiring diagram......Leave a comment:
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Re: Syncmaster T190 - a headache
Hi,
See the attached service manual, try to use the troubleshooting guide....Leave a comment:
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Re: LG 55LS4500 Sound but no picture
Hi,
The power for the T-CON is comming from the mainboard, via the ribbon cabe.
You can do a short test, to check what voltage is arriving at the T-CON connector:
-remove the small F1 2A/125V fuse from the T-CON.
-connect the ribbon cable into the TCON, and it's screws (to have good GND)
-measure with a multimeter, the DC voltage by putting the COM probe at any point of GND (could be top pad of C1, or the pads of C162-165) and the RED probe on the top pad of the fuse F1 (F1 removed).
If you get 24 V...Leave a comment:
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Re: LG 55LS4500 Sound but no picture
Hi,
From your description, I can presume the following:
-backlight on and sound on equals power supply and mainboard most likely ok.
-replacement fuse tripped, means T-CON fault, excessive current draw, a short circuit probably.
I see a voltage convertor (U11 is the controller), wich creates two voltages (because of the two big inductors), and two switching transistors (Q1 and Q2 - six-leg devices - most likely mosfets).
Find their datasheets to identify the terminals and check for shorts. Do the same for the...Leave a comment:
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Re: Apple TDK PSU
I pointed the suspect component below. Could you check if it's a crack or just paint line.....Leave a comment:
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Re: Apple TDK PSU
Looking at the picture, there is also a component that might be a varistor, wich is split in half (or so it looks).Leave a comment:
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Re: identinfy this component please
Hi,
I think you have mixed up the parts. In the pictures attached you might have two zenner diodes, but the part no indicated on the boards (ZNR105/106) are for two varistors. Attached you can find the part code for INR10D561, wich is a varistor, 10 mm diameter, disk type, 560V ....Leave a comment:
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Re: HELP my Monitor display says: RGB No Input
Hi,
First - might sound stupid, but reconnect your monitor cable both on the monitor side and on the PC side.
Two - narrow down the issue, PC/Video card problem ?/ Monitor cable issue? / Monitor itself issue? so test your monitor on a different PC.
Third - report your findings and we shall continue from there
Leave a comment:
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Re: Toshiba 55HT1U 5vdc unstable
Hi,
Just looked on the Owner's manual for 55HT1U and they say the stand-by is only 0.6 W, so at this wattage, the mainboard should draw ~ 120 mA. Your 1.6 A drawn from the BK PS is way too much for a stand-by mode, so this points out to a mainboard issue IMHO.Leave a comment:
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Re: Hyundai W240D
Hi,
It seems you have a problem on the inverter side. Please post some pictures with it (it's the board underneath the metal shield).
Also what voltage you have on the connector P500 (power supply board) between GND and 24V labeled pins and also between GND and On/Off pin on the same connector ?Leave a comment:
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Re: Samsung SyncMaster 943BM - backlight only for half a second
I don't think it's necessary, according to the voltages posted, on pin 10 wich is Chip Enable there are 2,89 V, well above the 2V treshold.
Also the 5,13 V on the Vdd pin indicate a correct operating voltage...
Voltages on pins 3 and 12?Leave a comment:
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Re: Samsung SyncMaster 943BM - backlight only for half a second
And beside pictures, can you post the voltages on pins 2, 5, 6 and 10 (respective to GND) of the OZ9939 to see what protection kicks in ?Leave a comment:
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Re: Hyvision by Megavision MV220 LCD monitor goes blank after 0.5-1 second
Hi,
The top hole is for negative lead and the one where your arrow points is positive.
As you can see, from the bottom, the positive lead of the capacitor is linked to pin 17 of the FAN7311 , wich is Vin.Leave a comment:
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Re: Samsung SyncMaster 943BM - backlight only for half a second
If you have had a shorted component, the fuse should have blown by now.
This trick can be used if you determined that the inverter is ok, and positively identify one CCFL with problem, and you leave it disconnected.
If you are willing to compromise, than you can consider this a temporary fix (dimmed brightness) i suppose.Leave a comment:
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Re: Samsung SyncMaster 943BM - backlight only for half a second
Well, it is 0,25W regular, and should enable the inverter to work with a "tired lamp" 
Leave a comment:
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Re: Samsung SyncMaster 943BM - backlight only for half a second
Hi,
Just a thought - have you tried bypassing the protection circuit from pin 3?...Leave a comment:
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Re: Fixing Toshiba Regza 37" LCD TV
First thing through my mind - bad solder joints. Since you have pinched/pulled/pressed the connectors while testing, maybe some contact may have been reestablished, either on inverter side or on the power board side.
Some real photos front/back would shed more light into the issue.Leave a comment:
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Re: Fixing Toshiba Regza 37" LCD TV
Yes, correct. You should read a voltage close to 24V. Keeping the negative lead on pins 6-10, place the red probe on the fuse labeled F1, 12A/65V, on the side closest to the capacitor C2 and you should also read +24V. If not, double check the fuse with multimeter on Ohms scale (200) and the TV off. If reading close to zero Ohms > fuse ok, if reading 1. then the fuse is open (shortcircuit somwhere on the board).Leave a comment:
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Re: Fixing Toshiba Regza 37" LCD TV
Hi,
The power connector is in the middle bottom, looking at the photo.
Pins 1 to 5 are +24V / pins 6 to 10 -24V and pin 12 is inverter On or Off.
The connectors from the top are the outputs to the CCFL lamps. Be careful, there is a high voltage on those connectors (> 1000 V)Leave a comment:
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