Ok i am trouble shooting a power supply from a ilo Lct42ha36 that will not turn on,it has the red indicator light on and will flicker when the power button is pushed. After taking the back off i have found 5 bulged Capxon capacitors on the power supply. It is getting the 5vsb but no 3.3ps-on. So can the bulged caps cause the logic board to not send the 3.3? And when jumping the 5vsb to the 3.3ps-on you refer to a 3.3k resistor. I am ordering the caps from digi-key and also want to order a resistor but it wants watts so can someone let me know what resistor is suitable for this please.
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Re: 3.3k resistor
I don't understand how you figure out that resistor, how your logic goes.
The resistor has color lines on it which tell you the value in ohms, don't just estimate the value of some resistor based on some wacky logic.
As for watts rating, that you can usually determine by the size of the resistor. Generally, it's not a problem if you use a resistor with a higher watts rating, that just means it won't heat as much as a resistor with lower watts rating.
If your resistor is too low on watts, it will overheat and burn out. -
Re: 3.3k resistor
What i am refering to is after read some posts on testing the power supply we can use a 3.3k resistor to jump between the 5 volt stand by and the ps-on which should recieve 3.3volts from the logic board when the power button is pushed which in then turns on the rest of the power supply and then we can test for the 12volt and 24 volts.Comment
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Re: 3.3k resistor
1/2 watt should be fine.Comment
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Re: 3.3k resistor
Thanks for your replies guys.Comment
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Re: 3.3k resistor
I am testing the voltage regulator U3 and with black lead to 1 and red to 2 i get 3.24v, black to 1 red to 3= 5.08, black to 2 and red to 3 = 1.83.
is the 3.24 to low thus a bad voltage regulator? it is a ams1117 3.3 0638.
Also i have some new AP1117EG-13 regulators that i used for a vizio repair, would these work for a replacement on this one?Last edited by eagle00799; 03-10-2013, 11:08 PM.Comment
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Re: 3.3k resistor
I might have measured the voltage regulator the wrong way, i read it somewhere. but i measured it this time by grounding the black lead to a chassis screw and got the following readings. pin 1=0.00, pin 2=3.24,pin 3=5.08. When i try to measure voltage at the ps-on when i try to turn it on i get readings in motion including OL. Any ideas?Comment
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Re: 3.3k resistor
Hi guys, i am hoping one of you can give me direction with this ILO lct42ha3. I know its old and out dated to say the least but it was a freebie so i thought i might be able to bring it back to life cheaply.
I am not getting the 3.3volts to the ps-on but i do have the 5volts to standby,the tv would not come on it would just stay in standby with the red light on. i do have some bulged caps on the power supply and have them on order. I put 2 AA batteries together and jumped the ps-on and the tv came on and worked as it should,I even disconnected the batteries and it stayed on so are the batteries energizing something? if i shut the tv down it will not start back up without the batteries in place. Can these bulged caps cause this? I included a few pics of the main board and power supplyAttached FilesComment
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Re: 3.3k resistor
Yes, bad caps can cause intermittent or unstable power. Replace those to get a baseline before doing any further tests.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: 3.3k resistor
Thanks Tom, I will let you know the outcome.Comment
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Hi
I am trying to repair an ancient Dell 2209WA Monitor which suddenly shut off with a pop sound. On investigation found that one of the fusible resistors had blown. Further investigation identified multiple components as faulty because of which the fusible resistor blew. Please refer the attached circuit diagram showing the components that were found to be damaged.
1. FR950 - blown fusible resistor - 0.2 Ohm 1W
2. Q950 - shorted Q950 MOSFET - 650V 10A N Channel Mosfet
3. R835 - Blown Resistor - 20KOhm SMD resistor
4. D930 - Shorted Schottkey Diode... -
Hi to all forum members,
Got this faulty 350 watt atx psu dirt cheap from a local online seller as i am keen to use it as a learning tool to repair faulty power supply.
The faulty part is quite obvious from the burn area near the 16pin KA7500 BD pwm. The fuse is still intact with good continuity.
Upon power on ac, there is 5vdc standby power on cathode of diode D14 and about 10vdc on cathode of diode D13.(This should be the aux power to generate the 12v and 5v rail.)
Initially i replace the two burned resistors near my marked red arrow to 200 ohm resistor... -
For today's thread, I have a KingWin ABT-650MM ATX PSU. Official web page with the PSU specs is still up and can be found here:
http://www.rmac.kingwin.com/products.../abt_650MM.asp
I just can't help it when I see a broken / for parts PSU on eBay that's listed for cheap and looks at least somewhat interesting. Well, OK, I won't lie – on the outside, this PSU looks anything but interesting. It's a plain gray box with colorful “spaghetti cables”.
What mostly drew me into buying it is its 2x PCI-E power connectors... -
I am curious if a 0402 resistor could go from 43 ohm to 0. In electronics class and my experience a resistor can degrade and gain resistance all the way up to not being able to conduct at all. I have never heard of a resistor decreasing in resistance and becoming 0 ohm or a dead short… that's not the direction they fail… or so I thought.
I was attempting to remove a wson8 chip on an iMac motherboard and it required a lot of heat, on one side of the chip were 3 0402 resistors that were very close. I popped the chip out unintentionally out of the tweezers and sent those resistors... -
The resistor on this waterpik blew. I changed it with the a similar spec 47ohm 2 watt yageo resistor but it still keeps blowing the resistor. Checking with the multimeter the motor, capacitor, diodes, and thermal fuse all checked normal. Will a higher ohm resistor work better? What ohm resistor will work better to repair this waterpik? This video is showing the repair with a 56 ohm resistor https://www.youtube.com/watch?v=_J7_rV7ui1Y
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