Translate this page:

Welcome to our forums. Please sign-in or register

Please help! - Signal strength problems after whack.

Posted: 22:22 14 Nov 07 #1
  • stu_h2
  • 3 Posts
  • Join Date: 14 November 2007



Managed to give my K800i a serious whack. Now have problem where the signal is low but intermittently so. I'm also getting a lot of "Emergency Calls Only" and "No Network Coverage" messages - I guess because of the poor signal. The signal strength seems to fluctuate a lot if I'm holding the phone. If I leave it in one spot I get about 4 bars (out of 5) and "My Phone Explorer" shows only about 39% (-73dBm), I would usuallly be getting 5 bars and about 70% on a good day (I'm out in the sticks a bit with no 3G coverage sadly). The local coverage is normally good enough that I maintain a signal at all times. It's not some weird coincedence because I can put the sim into an on old panasonic and get full strength with no problems.
I've opened it up and can't spot anything obvious. I have another K800 that won't even start (display just flashes) so can compare the two physically but can't really swap components as the main circuit board on that one is slightly bent (another even worse "whack") and the LCD is cracked (though flashes).

The metal cover that shields the back of the camera unit seems to pop off too easily but that shouldn't cause a problem. Should it?

I assume that the antenna is the circuit stuck onto the grey speaker housing at the top of the phone (it has UMTS written on it). If I'm right about that it all seems OK. The two flexible metal contacts seem to make good connections.

Can anyone offer any suggestions (apart from be more careful!)? I'm wondering if the external antenna 'socket' under the rubber bung could be used to check if the internal antenna is not functioning OK.... if so anyone know the best place to get an external antenna. That's assuming I'm correct in thinking the rubber bung is the external input?

I'm wondering where the antenna signal goes to on the main circuit board, it isn't really easy to see it. Anyone have more info on the phone or can even suggest anywhere I could take it/send it to for a reasonably priced once over? I am an electronics engineer by training but not when it comes to phones!

Thank you for any help.


Posted: 07:56 15 Nov 07 #2

It could well be down to the antenna or even the SIM housing.  Do you have insurance you could claim on for it?  You're right in thinking the antenna is at the top of the phone.  It's usually a bent bit of copper or something similar to that, which gives good signal retention.  If you can see no damage, it's likely that the joint to the mainboard is the problem but I don't have stripdown guides for the k800i.  There may be some on though.

Failing that, you'd be better speaking to Kuehne & Nagel about the phone being repaired.  These things have a 2 year warranty from new so you could still be covered, although you DIDN'T open it, right? ;o)

Pete (I need JD) Graham ************** Pete has fallen in love.

Posted: 12:15 15 Nov 07 #3
  • stu_h2
  • 3 Posts
  • Join Date: 14 November 2007

Thanks Pete.

The antenna joint seems OK and I've re-aligned the copper connections. I did a test with an old Sony Ericcsson screw-in antenna lashed to the conections and managed to get a fairly stable 30% ish signal. This said to me the internal antenna must be basically OK as the strengths were similar (if possibly a bit more stable with the lash up). I then tried plugging a Virgin SIM in (I'm on T-Mobile) and managed to get a signal strength of about 50% so higher than I'm getting with the T-Mobile SIM. When the network drops out and I get the "Emergency Calls Only" indicator the strength goes up to about 55% with the original SIM and antenna. If it made sense I would say some sort of software glitch has kicked in which has put the phone into a low signal gain setting.... but I know that's a bit bonkers as the phone was only dropped and I doubt such a software mode exists.

The SIM housing seems to be OK.

 I rang Kuehne & Nagel hoping to speak to somebody technical for a brain picking few minutes but they wouldn't/couldn't put me through to anyone. They quoted £11.75 if the unit was returned unfixable, which would be the case if the main circuit board was damaged (too expensive to replace) and £47 for any other hardware repair (LCD replacement or software problems would be different).

 I suppose my house insurance might cover... haven't checked. Would the 2 year warranty cover a heavy impact? Surely that's beyond the terms? And errrr no, I..... errrr... didn't open it.... honest!

Posted: 13:17 15 Nov 07 #4

What heavy impact?  I thought it was like that when you powered it on this morning? ;o)

Pete (I need JD) Graham ************** Pete has fallen in love.

Posted: 14:58 15 Nov 07 #5
  • stu_h2
  • 3 Posts
  • Join Date: 14 November 2007

Errrr yes.... and the case damage is nothing to with it!!!

Posted: 15:05 15 Nov 07 #6

Crap.  Maybe they won't notice?

Pete (I need JD) Graham ************** Pete has fallen in love.

Posted: 11:39 27 Mar 08 #7

Did you ever get to the bottom of your problems with signal strength on K800i?

 I have identical problem after dropping my k800i. Attaching an external aerial solves signal strength issue and otherwise phone seems entirerly normal.

 I was thinking of buying a new aerial block (only about £6) but there is nothing obviously wrong with the existing one just by visual inspection.

 Any advice?


Posted: 15:06 27 Mar 08 #8
  • anitalg
  • 10490 Posts
  • anitalg
  • Join Date: 4 March 2006
  • Occupation: Sitting quietly in the corner
  • Location: fingers in ears singing lala
Did you damage yours too? If not it could just be you have poor signal
Please suggest any improvements or report problems / abuse to