C850 no display. Why?

January 10, 2015 at 06:30:40
Specs: Windows 7
I have got Satellite C850 (PSKCCA-04H010) with similar problems posted in this forum. Again I will brief it out here:

(1) Laptop turns on with Num Lock on but no display;
(2) external monitor shows no signs of life; (3) after few minutes the set turns off itself.

After applying all the mentioned (in the forum) steps laptop is in same state with a minor improvement. Having a repairing experience I dismantled the whole unit including the LCD panel the only change I noticed is that the unit is not switching off anymore. Below is the list of things I did:

(1) Cleaned all the sockets on MB;
(2) Opened the LCD panel and did the same as step-1;
(3) Checked the CMOS battery volts. Its showing 2.99 volts.
(4) Cleaned RAM module.
(5) Couldn't find the LCD lid on/off switch which puts the laptop in sleep mode but it appears to be working fine. As soon the cover is closed all the lights go off and they come back on opening the cover.
(6) External monitor is still not working.

My conclusion: It appears the laptop is booting because its responding to FN+F12 (wireless) and power button with 5 seconds delay press time. Shall I suspect the AMD graphics chip which is embedded on MB or is there anything else I may be missing?

Any suggestion will be much appreciated.

Aditya Naulakha.

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January 10, 2015 at 10:01:10
See the 6th post in the thread linked below for information on how to use an external monitor. This may help diagnose your issue.


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January 10, 2015 at 17:33:11
Still no luck! Having an external monitor connected I pressed Fn + F4 key several times with few seconds delay but there is no activity on either of the screens i.e. laptop or monitor. Pointing the lamp on the screens there is no illumination of any sort.

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January 10, 2015 at 21:07:06
Try Fn+F5 simultaneously as stated in my link.

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Related Solutions

January 11, 2015 at 02:49:31
I had tried more then 10 times as per your directions. I am planning to reflow the motherboard to fix this problem. What is your advice?

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