First post, by gordesky1
So i have a compaq Presario 1675 parts machine from ebay which the seller said he pretty sure it will boot right up cause he cant test it cause no plug for it but dont get my hopes up. To fix my crack lid on mine or if it works i just use that and use mine for parts.
But the question is i also got a compaq 1692 which i bought new in 99 and 2 weeks ago it refused to boot.. It will power on but no display no beeps and it seems like it hangs cause even the cap light key doeisnt light up..
So went researching and found that it seems to be a common issue with these compaq Presario 1200-1600s that when the cmos battery goes to low asoon as you give it power from the ac adapter it can dry the bios chip making it not bootable anymore?
heres what the guy said i found on another forum.
This is a problem that has driven Presario 1200 owners nuts for the last 5 years...The problem is that the cmos bios chip develops an intermittent short, when powered up, the power/peripheral chip does an initial read of the cmos bios to determine its integrity. If the bios chips does not respond with the right bits, the laptop will not start. The solution is to replace the bios chip, an Atmel 49F002T, with either the same package (TSOP) or a PLCC package....See the entire horror story here, but the good stuff is about 3/4 of the way down:
http://www.ltcomputers.com/compaq.cfm This link doeisnt work anymore by the way..
While it is true that replacing the cmos batter may cure the problem, it is only a temporary fix because (I believe) that when the cmos battery falls below a certain voltage, spikes from the switching of the power supply and internal battery causes a breakdown of the junctions on some pins of the 49F002T (notably A10 and /OE). The article makes for interesting reading, and the solution emerged after about 1.7 years of complaining and investigating...but the solution didn't come from HP...infact, they stifled the efforts to provide a solution.
Good luck
John
But anyways the ebay seller said it sat for 10years with out any power.. So what i wanted to ask is should i just remove the old cmos battery before i even give it power when i get it till i can get a brand new battery for it? It doesn't hurt to run a board with out a cmos battery in it right?