Thinkpads Forum

Hi,

I have a very old Thinkpad 300 without power supply.
I don't found pinout on the web and on the Hardware Manual Maintenance ( Vol 1 )

Voltage is 15.5V

It is 2 big pin probably for the 15.5V and another 6 pin.
For this pin, 2 are connected probably a detect mode for power supply and 1 have a capacitor between the 2 pin this pin.

I have soldering a standard connector on the 2 big pin ( found sence with polarised capacitor and a diode ) and it don't start.


I need help.
Thanks


PS : Sorry for my poor english but French.

Hello and welcome to the forum,

Well, You made a big mistake by soldering a standard 15,5 Volt power suply to those 2 "big" pins. I have the original power supply and it has 3 different voltages, that are passed to the laptop:

15,5 V at normal supply,
14 V at battery charge
plus 5 V signal (this one is passed on two pins)

What You actualy did was soldering the power supply to the +14 Volt and +15,5 Volt - no ground...
In a moment I will post the pinout of this power supply. Also I hope that You didn't damage this great antique.

edit:

the pinout:
http://img529.imageshack.us/img529/2217/file0007p.jpg

I hope that this helped You somewhat

Thanks ... i have all bad !

I have soldering the 14V charge to the GND.
I go make a test with the 15.5V power and the GND only.
It only for collector and i don't need use battery.
Many time, i remove cells from battery.


Thanks.

In Europa it is hard to have some modele but all country have different keyboard.

attilavv wrote:Thanks ... i have all bad !

I have soldering the 14V charge to the GND.
I go make a test with the 15.5V power and the GND only.

I wouldn't do it if I were You. If it needs 3 different voltages than I would recomend using all of them - no mater if the laptop has a battery in it or not. keep also in mind that You also need two sources of +5 Volts... .

For the Two +5V it it probably some information for power supply.

One for signal a battery is present ????
One for signal laptop connected ????

I don't no if it some LED on the power supply.
If yes, it is probably same old power supply from Compaq.


Edit : TEST OK !
I have soldering a connector for a standard Thinkpad.
+15.5V ( power supply is 16V and tested at 16.5V )
For the GND it is ONLY the group of two pin ( another GND is for another ... )

+14V charge not connected.
+5V all not connected.

Edit 2 :

HDD is dead ( bad ? ? ? )

It is a very old Conner CP2083.

1 - Make some test on a desktop ( with adapter ).
2 - Open it Yes some time i win and move magnet on the head, unlock the head and test it. ( some time disk or head is very dead with circle hole )
3 - Found another compatible HDD ... and priest for the bios ... ( I have a Conner 120 in my stock )

It start with "bad battery for CMOS" and YES she is very, very bad ( i must remove it ) and time message.
At this time, a don't test HDD, KBD. Only screen ( White & Black )

Now ... big query ... change power connector or found how to place to wire for a second external connector.
In my showcase, all thinkpad can works ( many many wire and power supply ).

Hi. At my job we've got one of this venerable thinkpad 300 and it could be used for manage a legacy system. I'd need the pinout to test if it is still alive. I've tried to follow the link given in this thread but is dead. Four years is quite a long time. Could you be so kind to place the picture again? Thx.