hi everyone,

my friend gave me an old compaq presario 1690. it was a complete mess when i got it. the notebook did not have a dc jack and the ub port on the back was completely ripped off. it was in horrible conditions. the first thing i did was buy the dc jack and solder it to the back of the motherboard. the thing worked great it powers up the motherboard and charges the battery. i hear the harddrive turn on and the fan kicks in only when is connected to the power. the dvd rom open closes and when you stick in a cd you notice that it reads it by the noise it makes. my only HUGE problem is that the lcd screen seem to not be responding. i have messed around with the cables from the monitor several times to see if its doing a bad contact but still cannot get it to connect. i even connected a monitor the the back of the notebook and i hear it when the monitor is connected but nothing displays on the monitor. what else can be messed up on the motherboard that cannot be sending a signal to the lcd screen?

Thanks in advance!

Hi, First of all well done on getting the power jack soldered in correctly.

If there is a blank screen then its usually one of the following to blame

1 An incorrect setting with your function keys........ try Fn+F5.... but look for the icons on the F keys they usually act as a toggle function, one press Laptop screen, 2 presses external monitor etc..see how you go.... if all else fails see the manual, download if necessary) You may have to try different keys so a lot of trail and error will be required.
2 You can sometimes duplicate the effect by using the ALT key +the correct Fkey
3 Try connection to a known good working external monitor....try step 1and 2 again
4 After booting up (try in safe mode as well) shine a bright light from a good powerful hand torch onto the laptop's screen ,,,can you see a ghost image of Windows dimly represented? In the workshop we use a powerful desk lamp shone on the screen and this is adequate to enable us to easily alter settings
(Don't forget that this machine originally shipped with Win 98)
5 If you can't get a picture on an external monitor then the lookout is not too good
6 The usual thingws to check are :
7 Damaged cable/connectors (laptop to screen)
8 inverter board
9 Back light
10 U/S screen

hi paws thanks for your reply.

i went ahead and followed the steps you gave me. nothing seems to working. when i turn on the notebook the num lock caps lock and scroll lock lights light up, but for some reason i believe that the keyboard is not working or the motherboard itself is shot or something. now i know i solder that piece right and didnt damage anything becuase i have a dell inspiron 5160 that are prone for the dc jack to break, which broke and i fixed it without a problem. now again this presario was giving to me in horrible stage. i dont know what my friend did to it. the dc jack from it seem to have been pulled out since it only had the 2 silver connectors somewhat soldered and everything else was missing from the dc jack. can the motherboard itself be defected? i tested out the keyboard by trying ctrl alt del several times to see if it would restart the comp put it just does not do anything. i pressed every Funtion key the notebook has holding down the Fn key the atl key and even the ctrl key and nothing. i hear the external monitor receive the signal from the notebook becuase even though the monitor is already turned on it does that static noise. but nothing comes up either way. it is none responsive. any ideas?

P.S. if your wonder i have to accts here because i totally forgot i already had an acct in this forum. ( yousamook = larryri42)

This post has been edited by yousamook: Apr 1 2008, 08:01 AM

Hi, If you can't get anything on the external monitor at all even from boot (or when you try to boot) then its beginning to look like bad news
the fact that you cant even see the POST and BIOS load on the external monitor is not good......

All I can suggest is that you carefully dismantle the machine again and see if you can detect any problems with the mobo or subsidiary cards by close visual inspection...a hand lens is useful here....you are looking for a dry joint, wire disconnect, bulging capacitor, break in a PCB etc. In the absence of test gear that's about all you can do.
Obviously its uneconomic to take it to a repair shop, but it would be very satisfying to get it all working again.

It might be worth having a look on ebay and see if you can pick one up ( they will be very cheap) you may be able to buy a new mobo for a few pounds (dollars) and if so then its worth taking a chance just to see if you can get your old friend working again. You can often find them sold as for Spares or Repairs and often it will say if they will boot up or not.

I can understand your feelings as I have an old Compaq P3 800Mhz laptop that I am very fond of and that works just as fast and as well as a lot of new stuff and I'm determined to keep it going for as long as possible.
Regards
paws