You wont ever find a schematic for a laptop. The best you can hope for
is a "Service Manual" which basically tells you how to take it apart
and where the screws are. Your fault is unlikely to be a power supply
fault, more likely to be the main CPU or the BIOS. Suggest you try
Google for info on these items. I wont bother going into great detail,
but these items are easily corrupted/damaged by static.
Good luck.

"Brad" wrote in message
...
Hi,

Part of the internal DC-DC inverter (SMPS) is not "running" which
I assume
powers the drives (HDD and floppy), etc. There are three
transformers and
using a scope with a pickup loop, one of the three transformers is
not
"switching" with laptop turned "on".

Note: LEDs that are on, cannot be turned off using their related
key (eg.
Caps Lock). See details in my previous post below.

I have searched everywhere for a schematic. I have the "service
manual"
(.PDF file) for this model, but it doesn't have schematics.

I tested (in circuit) the parts in the internal DC-DC inverter
and I have
not found a defective part. Checked all solder joints. It is
possible that
an outside "control" that normally activates the SMPS is not
functioning.

Does anyone know where I can get a schematic for this or a
similar
model laptop?

Thanks in advance, Brad


On Fri, 16 Feb 2007 13:58:26 GMT, you wrote:

Hi,
My brother gave me his "dead" Compaq Armada 4210T laptop to
repair.
I normally service TVs and other stuff. With fully charged
battery, when
I turn it on (push power button), almost nothing (no hard disk spin
or floppy
disk drive noise (with floppy in drive), no "beeps" or lights, no
display
(even with external monitor)) happens when you turn it on except 4
(power, caps lock, scroll lock, numb lock) of 5 LEDs light up.
I removed the battery, but the same thing happens using only the
external
power source.

With the room totally quite, if I put a floppy disk in the drive,
I can
hear a faint noise when I turn on the power (but floppy drive
doesn't run).
If I remove the floppy disk, it isn't there.

I measured +5 volts (after power turned on) at one of the pin
connectors for
external keyboard, which tells me that the internal DC to DC
inverter
is "running".

This failure wasn't the result of a power surge, as in a storm.
No advance
warning of any kind and the laptop wasn't dropped or abused. I
thought
possibly a static discharge from his body after walking across a
carpet, but
he said, he doesn't recall that event?

I opened the unit and found a tiny 5A fuse, but that tested good
(not open). I examined circuits for bad solder joints. Also
checked for
loose connections of any kind.

If you ever had this experience, please tell me what you did to
fix it.

Thanks in advance, Brad

Before you type your password, credit card number, etc.,
be sure there is no active keystroke logger (spyware) in your PC.