Image of Bottom of Motherboard, HP Pavilion XT155 laptop

SNIP

https://www.mynaq.org/hp-compaq-nx90...75-dakt7imb8d4

The board in question has an ALI chipset. Does yours have an ALI chipset
or are we on a wild goosechase ? It uses an ALI M1535+ and it has an ATI
GPU fitted to it.

You can see an RTC battery in this picture, but I can't make
out the notation on the battery. There is a button that looks
like "Clear CMOS" button nearby.

https://www.mynaq.org/image/cache/ca...56-800x600.JPG

There's just no warm and fuzzy feeling here, no "positive ID".

You have a better idea what's in there than I do.

Paul

Hi Paul,

I don't know at this moment if this board has an ALI chipset.

I saved all the images. I don't need to know the battery number, just
it's location on the board which seems to be on the bottom of board.

Some of the ports (external monitor, serial, parallel) locations seem to
match this laptop.

I will examine the images very carefully before I make any conclusions.

Hi Paul,

UPDATE:

Thanks to you and that link to the images, which is a MATCH
to my laptop, I was able to cut (dremel tool) an openings at the
CMOS battery location and remove the battery (ML1220 rechargeable).

Note: That "button switch" near battery is a "Reset" (not for clearing
CMOS memory).

With the battery removed, I am going to wait 24 hours or more for CMOS
memory to clear (did that on other HP laptop years ago). I measured the
battery voltage, it was around 2 V. Note: CMOS battery may have run
down to a low voltage, corrupting CMOS memory. Then charging that
battery (AC adapter plugged in (Main battery was defective & removed))
has "sustained" the corrupted CMOS memory.

After a day or so, I will hook up wires and use external 3VDC source
to see if this laptop will boot up without those 4 short beeps from POST
before I install a new battery (have to order one).

I am hoping that the CMOS memory became corrupted like it happened
on a different model HP I have years ago.

Again, Thank You Very Much for your help, John