Hi everyone,
I have a Compaq Armada 7770DMT laptop, when I plug in the power cord, all three lights stay ON.
Pressing power button does not turn on the laptop. Tested with hard drive and without.
Does it mean the motherboard is broken?
Is there anything I should try?
Thanks.
may have got a power-shock , try removing everything (battery , hdd , ram,power from circuit by holding power button for more than 1min ) and use a good known power adapter. If it beeps , than you may have a chance. If not you need soldering skills to fix motherboard
It can be first resistor , or mosfet or regulator or something. (I have one laptop that had a spiked power adapter on me,at-to 20v and it need-ed 9v or something and still was not able to fix her yet. 91 model.)
is this COMPAQ with integrated poweradapter? may have issue in that... (separate part attached to motherboard).
Thanks @ediflorianUS. Yes, it has integrated power supply.
I found an YouTube video which shows the same issue: https://www.youtube.com/watch?v=L_zhDDt2WyA
I am going to remove the motherboard and check if any damage on it.
I hope it's a quick easy fix. My goodness, when my 1st retro laptop conks out I'm not going to be a happy camper.
There's usually a big ~6v nimh battery pack inside the laptop for standby purposes like suspend to RAM. If that's not removed it can leak and damage traces - I recommend checking that on any of the Compaq LTE & Armada laptops up to about the Pentium II era.
Somehow I got lucky with my Armada 7350 and the battery was already gone so no corrosion. But the Armada 7400 I bought for the caddy had corrosion so bad that the system would break if the CD-ROM was hooked up at all. Mainboard replacements can be relatively cheap though since it's the accessory parts like screens, keyboards and hard drive caddies that appear to be relatively rare. That means a lot of systems get broken down for parts - I think the replacement Armada 7400 mainboard cost only something like £15
@Thermalwrong If I remove battery pack, do i need to reset the clock every time I unplug the power cord? The Li-Ion battery pack no longer hold charges.
If the main Li-ion pack is removed / not working as well then yeah it pretty much won't keep time anymore.
It doesn't seem to complain though, just starts up with some random time.
But you could potentially put a fresh battery in there for it to run the RTC, the existing one is quite likely leaking corrosive electrolyte through the cables.
any news?
I managed to open the laptop. It looks like corrosion near the CMOS battery connector.
I did try to power the laptop without CMOS battery, hard drive and floppy drive. It shows the same symptom - all three lights stay ON.
Do you know if all the Compaq Armada 7700 series uses the same motherboard?
I think I will buy another 7700 from eBay and replace the motherboard.
sangokushi wrote on 2023-06-08, 10:40:I managed to open the laptop. It looks like corrosion near the CMOS battery connector. I did try to power the laptop without CMO […]
I managed to open the laptop. It looks like corrosion near the CMOS battery connector.
I did try to power the laptop without CMOS battery, hard drive and floppy drive. It shows the same symptom - all three lights stay ON.Do you know if all the Compaq Armada 7700 series uses the same motherboard?
I think I will buy another 7700 from eBay and replace the motherboard.
I think it's close , clean with contact cleaner and check the L4p diode... *may be bad. (is te fuse ok next to C662)
I will check my collection see if I have any 7700series but I don't think I have.
ediflorianUS wrote on 2023-06-08, 13:06:I think it's close , clean with contact cleaner and check the L4p diode... *may be bad. (is te fuse ok next to C662)
I will check my collection see if I have any 7700series but I don't think I have.
Can you tell me where is the L4p diode?
The fuse is ok (I assume it's the component in the circle)
I googled search and found the motherboard board part no: 291736-001 https://www.elhvb.com/mobokive/edwin/laptops/ … mpaq%207710.pdf
I thought 7700 series are using the same motherboard, but the part no. are different.
I just setup an eBay search for 'untested' + 'power on', + '7770DMT' and hopefully a cheap one will come up soon.
Thanks for your help!
it's str8te up from the fuse , It seemed oxidated , and located where can be bad but maybe I am wrong. Anything in particular warming up to HOT? on the MB? Maybe try checking the oxidated traces/may get lucky and one(or two) is interrupted
I'm having similar issue here Help / Advice repairing battery leak on Compaq Armada 7710MT if somebody has clues, thank you!
