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
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.
>