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ndallari

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Thinpad dim display

I am fixing a IBM thinkpad t41p for a friend and it is turning in to a nightmare.
1. the first problem was the CPU/Video processor fan assembly that had to be replaced because it became noisy and the inoperable and the system would shut down.
2.  The system seemed to be working fine but my friend called me back two days later and he said his screen was black. When you boot the machine you can see a faint image of the bios screen and then the xp login screen very dim.
3.  I changed the inverter and it lasted for about an hour until the same problem occurred.  The screen started flickering and then went dim and I am back to square one.
4. I was not thinking to clearly and decided to change the florescent lamp (what a crazy idea). It did not fix the problem at all.

It seemed like the inverter was the cause bue why would the replacement inverter go bad so quickly.  I know it was used but I do not think it was a coincidence.   It also does not seem to be a coincidence that this happened a few days after the cpu fan was replaced.

Nick
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rid
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Perhaps you need to check the cable from motherboard to screen for bad seating or damage. A break in one of the leads may cause a total failure. Also, if backlight power has its own cable, check that too, including connectors.
/RID
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Are you sure the inverter you used was completely compatible ?
Was it new ?

I hope this helps !
OK, two things will do in an inverter; excessive current loading due to a bad bulb or a bad DC power supply providing too low of a voltage (which causes the inverter to use more current).  Once they're fried, they tend to be fried.
Having changed the bulb ( and yup, they're no fun to change), you probably ought to try another inverter (how about getting it warrany exchanged. It did work for only two days)
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ndallari

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When I tested the unit I did not have it plugged in to the power supply.
I just ran it on battery.

I can request another inverter but I was afraid the same thing is going to happen.

Thanks
NIck
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Davis McCarn
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Is the DC supply capable of frying the inverter?

Thanks
Nick
Poor solder joints, a partially fried diode, or bad capacitors can cause the voltage to be lower than it should be, to be noisy, or to have ripple.  Lower voltages cause the current consumtion to go up.  Yes, the DC supply is capable of frying the inverter; but, if the bulb was dying, it would stress it more.
Use an external display and a stress test to see what happens.  If it works OK for a few hours, the bulb was probably the problem.
An external display works without a problem for hours and hours.

Something interesting to note is that when I turned it on yesterday the display was working fine for ten minutes.  It seems with a complete power down and then a startup the display will work sometimes.

Nick
So, the mouse keeps working even after the LCD goes dim?
And, did you check on the warranty?
If the mouse keeps working and it is out of warranty, you need to get the inverter replaced.  It is a small power supply located in the display part of the laptop and they run about $30-40.  You will; though, need to know which one is in your laptop because the T60 probably has several possible displays.
I finally received the new inverter it worker for a little while and then the problem started again.
I also changed the cable between the inverter and the motherboard and that had no affect.

At this point I wll have to assume it is the motherboard.

Thanks for al your input.