I was asked today for some information about a voltage regulator on a T23 motherboard. Well, at least I think Ron was referring to a T23. Anyway, using a dead T23 motherboard (FRU 12P3770) that I keep on hand for reference, I decided to look around the board and see if I could identify some of the more "useful" components. Here is the start of the list and it is in no particuluar order:

- U41 (Top D5/E5) Maxim MAX1631AEAI Low-Noise Power-Supply (Controller (datasheet, reliability report)
- U27 (Top G5/G6) Analog Devices ADP3806 LiIon Battery Charger (datasheet)
- U30 (Bottom B7) Maxim MAX1718 CPU Step-down Controller (datasheet)
- U?? (Bottom E8) Maxim MAX1715 Dual Step-down Controller (datasheet)
- U4 (Bottom D8) National Semi 82CIMQA Remote Temperature Sensor (datasheet)
- U13 (Bottom F8) National Semi LM75CIM3 Digital Temperature Sensor/Thermal Watchdog (datasheet)
- U12 (Bottom E6/F6) Texas Instruments TPS2216A Dual-Slot PC Card Power Switch (datasheet)
- U8 (Top I2) Cirrus Logic 4299-JQ Crystal SoundFusion Audio Codec '97 (datasheet)
- U76 (Top G5) Toshiba TB6808F Power Supply Controller for Notebook PC (still looking for datasheet)
- Q16 (Top B5/B6) Siliconix (now Vishay) SI4802DY MOSFET; replaced by SI4778DY (SI4802DY datasheet) (SI4778DY datasheet) - see here
- U22 (Bottom J8) Panasonic AN17000A Audio Signal Processing IC for Notebook PC (datasheet)
- U31 (Bottom I6) Renesas (nee Hitachi) H8S/2169AV 16-bit Single-Chip Microcontroller (aka, the Embedded Controller) (datasheet)
- Q5 (Top B6) Toshiba TPC8002 or International Rectifier IRF7413 MOSFET (datasheet)
- Q17 (Top B5) International Rectifier IRF7807D1 MOSFET (datasheet)
- Q33 (Top B5) International Rectifier IRF7416 or Siliconix (now Vishay) SI4435ADY MOSFET (datasheet "D" version; "A" is obsolete)

These parts are listed by their component designation on the motherboard (if known), their location as shown in the two pictures I've linked below, the manufacturer (if known), part number and description. Where available, I've included links to datasheets or other information about the part.

I will be updating this list from time to time as I get curious about certain parts. I am still trying to confirm a source for the CMOS backup battery connector, so this list will not be limited to ICs.

Edit: (Feb 17 07 @ 4:23pm PST) - I have uploaded two scans of my T23 motherboard and have attached a legend to them so it will help identify WHERE these parts are:

Top side w/legend (158KB)
Bottom side w/legend (169KB)

cool.

Very nice job ray..
maybe i need better glasses but i cant find the power input jack !!.
dont embarras me to badly when you tell me where it is.(getting late for me).
tnx..ron..

It's on the I/O card, which is not pictured . I will probably get around to scanning that board and posting it on my site. When I do, you will also not find it ! I sold the DC jack to dsigma6 several months ago. I know that people have damaged USB ports or power sockets and I might be able to find replacements at Digikey.com or Mouser.com.

As a fun exercise, can anybody find a missing part on my scans? And, no, it's not the CPU !. I won't say which side it's on but if you have a T23 motherboard loose, you should be able to find it (well, okay, you won't be able to find it on my board ). I needed to pull that part from this board when I received a T23 that was missing one. And, again, no, it's not the famous part from the bottom of the board. I will say it's bigger than the size of the IBM logo at A9 in the top picture and smaller than the Intel 1.2Ghz CPU that's not in its socket.

What I may do later is provide the original high-resolution scans. They're good (and big) enough to read most of the part numbers from the smaller components. I actually scanned the board at several different resolutions so I'd have them as resources to look at when I don't have the board on hand.

Would it be the inductor looking part in the upper left hand side of your topside pic...just above the processor?

EDIT: In row A, columns 1 & 2.

Give that man a (virtual) cigar!

Woo hoo!!! Need a dead board to play with? I used one of my dead boards to check.

The board that is pictured in those scans is dead. Remember this conversation we had a couple of months back:

http://forum.thinkpads.com/viewtopic.ph ... 635#206635

If any one of the T23 motherboards exhibits the "blink of death", then yeah, maybe I would be interested. PM me off line.

Ray,

I opened up the t23 that had the 30volts applied to the power input and see a part on the MB in quadrant A-1 that looks like it melted. I do not see any part in your photo. What is this and can it be replaced?

I have ordered a used board and case from a person on Ebay but was wondering if this board could be repaired?

Thanks,

Bruce Hecht

Ah, sorry about that. The motherboard I used in that scan is/was basically my "spare parts" board. The large, ~ 1/2" square missing part is an inductor. You can find all of the details about it from here:

http://forum.thinkpads.com/viewtopic.php?t=56664

It can be repaired. Cheapest method is finding a non-working donor, a password protected sytem board is perfect if you don't want to fiddle with unlocking it. Those are cheap on fleabay. Never hurts to have one spare on hand.

T23 boards? I'll take a dozen!

Well, not a dozen, but a week ago, I saw a t23 board on ebay Germany. Seller was com.120
Ending price 1.50 euro.

If it had not been for the nasty shipping costs, then I might have tried to get it.

No issues except for a SVP? In that case I'll have to follow the Ebay offers more closely in future.

P.S. If you're in Denmark, it might be cheaper to have things shipped to me and then re-shipped to you. That's often an interesting alternative when sellers demand incredible prices for foreign shipping.

Thanks for the generous offer, Robby. It might become relevant one day.
And no, it was not just an SVP. I remember it as being described as "no picture".

Semi-gratuitous bump to highlight two new entries in the parts list at the top of the thread: AN17000A (audio processor) and H8S/2169AV (Embedded Controller). Also for the benefit of those of you that like to work on T23 systems and that might not know about this thread.