t23 problems

[CyberAxe]

I originally killed my ThinkPad by hitting the bottom part of the case with a Wiimote causing a component to come off the my mobo and causing the pulsing fan problem this was a few months before the solution to that was found so a few months later when I looked over the forum I took my ThinkPad to bits and saw that the bit had fallen off and soldered it back on

when I put it back together and powered up the pulsing stopped but the screen is black I can’t remember what the status lights were, I decided to try resoldering it but forgot to take the power cable out when opening it and fried the motherboard when taking the cpu out

I recently bought a new "faulty" mobo off eBay (getting a hold of one is extremely hard considering they are either too expensive and everyone attempts to bid on them so they can fix them up and resell them), it appears to have had the same component already soldered I put it in and tried powering it on but only the fan came on and the power kept dropping I tried putting my soldering iron over the solder and cleaned it up a little and it no longer powers off but I still have a black screen

it powers on status light 4 is on and the power light is on both lights are green but the screen is black the hard disk powers up but doesn’t do anything and I can hear it accessing the cdrom at power on

[rkawakami]

Welcome to thinkpads.com!

Couple of things to try, assuming that you are not getting any beep codes where turning the system on:

- does the external video port work? Connect a monitor to the VGA port, boot the system and see if there's anything there. You might have to press the Fn+F7 key combination to activate the external video.
- remove the MiniPCI card from the bottom of the system
- verify that the LCD ribbon cable is firmly pushed back onto the motherboard connector
- power up the system and shine a strong light onto the screen at an angle. If you see any activity (i.e., a ghost-like image of the IBM splash screen or the Windows desktop), then you may have a problem with the inverter or a broken backlight.
- if none of those things seem to help, remove the disk drive, Ultrabay drive and all memory and see if you at least get the 1-3-3-1 beep code
- take a closer look at the L8 and L11 inductors on the bottom of the motherboard and the L9 one next to the CPU. They may look like they're attached but if you lift them with a fingernail and it pops off, you may have found the problem.

With the system off and a battery installed, if you plug in an AC adapter, there should be either a yellow or green LED lit on the right hinge. Yellow indicates charging; green means that the battery is charged. Pushing the power button should yield a "thump" from the speakers, the fan spinning up (and hard drive if installed) and the four right-most LEDs lighting up at the same time for about two seconds, then only the right-most ("Z" looking icon denoting power) remaining lit. If there is a hard drive, the left-most icon (drum with a double-headed arrow) will flash as the drive is accessed. I've found that in some cases, flexing the front left corner of the base up or down

[CyberAxe]

Thanks for the reply.

It powers on like described but no hard disk activity

I've tried everything suggested so far to no avail, am about to take the mobo out again to check the inductors

[CyberAxe]

ok, I noticed the one beside the CPU had a cracked case when I compared it to the one from my other motherboard so I swapped them over, the one furthest from the one with 024 (can’t remember the proper names) came off rather easily when I pressed tugged at it with my nail

After doing those 2 I noticed it was still acting the same so I looked at the one I thought had been attempted to fix again and that came off rather easily so resoldered it back on fully

Now when I power on there's a high pitched squeal that builds up then the laptop shuts down its coming from the direction of the cpu/l9 inductor

i'm thinking of putting the original l9 back on from that mobo and see if that works

The squeal was caused by some solder from the inductor being over a couple of copper connections i removed it and its gone back to the way it was before

[rkawakami]

The two inductors on the bottom should be these:

- L8 will have "5R2" on the top row (with some other characters below it but they are not important); L11 will have "2R5"

The one on the top side of the motherboard next to the CPU (L9) will have "0R6NH". If you have an ohmmeter (multimeter) then you can test them to see if they are "open". With no power to the motherboard, set the meter on the lowest resistance range and put the leads across the two metal tabs; for the L9 inductor, use the two contacts that are on the same side of the part. You should read 0 ohms or very close to it. If these three are firmly connected to the motherboard, then there must be some other component(s) that are loose or defective.

I would recommend checking at least one of the crystals on the motherboard. I had a problem with Y6, just below the Intel 82801 chip and located underneath the speaker assembly. Two legs had microcracks in the solder joint and it caused the system to hang.

ref: http://www.kawakami-ca.com/images/t23_crystals.jpg

[CyberAxe]

Got my hands on a multimeter, all the inductors rate at 00.6 i tried it on the bottom 2 pins on the right most crystal and got about the same couldnt get a reading on any of the other pins or on the other 2 crystals

[rkawakami]

Inductors will read almost 0 ohms since all they really are is a large amount of wire wrapped around in a coil. Crystals cannot be tested with a ohmmeter; they would need to be placed into an oscillator circuit and measured with a frequency counter. Unless you can find something else on the motherboard that is not firmly attached or has obvious signs of distress or swap out the CPU with one that you know works, this is about the time that I would suggest that the motherboard is dead.

[CyberAxe]

I just attempted to start laptop without cpu and got same response so am ordering new cpu as i wouldnt be surprised that the cpu was kaput

hopefully this will work if not will probably have to fork out for a working motherboard which is gonna be somewhat expensive :/