The serial port has stopped working
Toshiba 1800 Laptop (PS181A)
The serial comms port has stopped working – I have looped back (connected pins 2 & 3 together on the 9 pin connector) and tried HyperTerminal. TX data (pin 3) stays at approx -5 volts.
Is the part for the serial interface replaceable (I assume it is on the Motherboard)? Do you know the part number?
You are right. The serial port is a part of the system board. The serial port interface is permanently soldered to the system board and I doubt if you can replace it at home. I guess you will have to replace the entire system board. Here’s a disassembly guide for Toshiba Satellite 1800, you can use it to remove the system board from the laptop.
Do you need spare parts for your laptop? Search here by the laptop model and part description.
June 18th, 2006 at 8:52 pm
Thanks for the advice. If the interface IC has not too many pins (eg I have seen a Texas Instruments 20 pin GD75232 surface mount IC use to convert the logic signals to/from RS232 – 3 drivers 5 receivers – on some PCI I/O Cards), it is possible to remove these at home. The technique is to gradually pull a thin wire under the leads (while heating them with a temperature controlled soldering iron) to lift them off the board. You then have to tin the leads of the new IC and heat them up in contact with the board – some solder paste will help with this.
The square packages with leads on all sides are more difficult. For these special soldering tips or hot air guns make life much easier, but you must be careful not to unsolder/damage nearby components. Some people try to mask the area to be heated by the hot air gun.
Any idea what a system board would cost – approximately? Is it economic to replace them for a laptop which is three to four years old? If not a “good” USB to Serial converter such as the Moxa NPort U1110, which you can lock onto a particular Com port number, may be the best solution.
June 18th, 2006 at 9:01 pm
Hey Roger,
I guess that you can find the system board on ebay for $60-$100. If it’s not available right now, just wait for it. Some internet stores asking about $350 for this motherboard.
January 9th, 2007 at 6:38 pm
How can I use standard portable desktop computer speakers with my Toshiba Tecra M2? How/where do I plug them in, and what settings to I need to adjust?
I also would love to use a full sized keyboard with my laptop, but can’t figure out how to make that work either. Do you need a special laptop keyboard? I just have a desktop keyboard.
January 10th, 2007 at 7:17 pm
Allison,
Most portable desktop computer speakers have the same jack as headphones. You can plug the speakers into the headphone jack and you don’t have to adjust any settings, just the volume control. You can use a USB keyboard. Buy a full sized keyboard that has a USB interface, or buy a USB-to-PS2 adapter so you can use the keyboard you have. The keyboard should be detected automatically as soon as you plug it into the laptop.
March 16th, 2009 at 4:22 am
my serial port stops workig automatically..sometimes after a few hrs or sometimes even after days! thn i hv to restart the serial port to get it working again.
plz help
any ideas?