UPDATE: Dead Compaq Armada 4210T Laptop (more details)


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. >
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I have been repairing notebooks for about 7-8 yrs. now and I have not seen one schematic anywhere, for any notebook. All you can go by is feeling your way around and trying to figure it out.


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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.

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Nah, never say never, one day someone will find one ...

Unfortunately not the OP's one ;-(

Mitac 7321

-- Adrian C

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Adrian C

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