Solved

External Monitor flickering on AC power

Posted on 2008-06-19
11
1,293 Views
Last Modified: 2013-11-17
Using the AC adaptor that came with my Sony Vaio laptop, my external monitor flickers. On battery power it's fine. I've tested the monitor with other PCs and it is fine. I've tried varying the resolution / refresh rate with no success.

The AC adaptor outputs at 6.2A, using the adaptor from a different Vaio laptop that outputs at 4.7A the problem goes away, however I am worried about the potential consequences of doing this.

Anyone any ideas how I could resolve this without having to buy a new adaptor?
0
Comment
Question by:NazoUK
  • 4
  • 2
  • 2
  • +1
11 Comments
 
LVL 12

Expert Comment

by:asidu
ID: 21820759
What is the indicated output voltage of the two AC adaptors ?
0
 
LVL 15

Author Comment

by:NazoUK
ID: 21820767
Both identical at 19.5V
0
 
LVL 28

Assisted Solution

by:burrcm
burrcm earned 250 total points
ID: 21820826
Don't use an underrated unit. The correct one appears to be faulty (AC leakage). I would replace it.

Chris B
0
The Eight Noble Truths of Backup and Recovery

How can IT departments tackle the challenges of a Big Data world? This white paper provides a roadmap to success and helps companies ensure that all their data is safe and secure, no matter if it resides on-premise with physical or virtual machines or in the cloud.

 
LVL 15

Author Comment

by:NazoUK
ID: 21820940
I don't believe the adaptor is faulty as I've tried an identical one from another laptop with the same results. The other laptop also exhibits the same behaviour.
0
 
LVL 28

Expert Comment

by:burrcm
ID: 21820994
<<I've tested the monitor with other PCs and it is fine>> <<The other laptop also exhibits the same behaviour>>. One of these statements is incorrect. Have you tried a different external monitor on your laptop?

Chris B
0
 
LVL 15

Author Comment

by:NazoUK
ID: 21821022
Neither of those statements is incorrect; I've tested the monitor on other (non-laptop) PCs and it works fine. Testing another Sony laptop that uses the same AC adaptor produces the same results.

I've tried several monitors with the laptop all have the same flickering.
0
 
LVL 12

Assisted Solution

by:asidu
asidu earned 250 total points
ID: 21822980
Since both xformes have the same output voltatge, both can be used. Having an overrated transformer is not an issue. If you use an under rated transformer it could be in an issue after some time.

Is it possible to measure the output voltage of the two xformers ?

Since you say your external monitors is OK and the same  problem persists on other system,  i reckon its a problem which need help from Sony.
0
 
LVL 15

Accepted Solution

by:
NazoUK earned 0 total points
ID: 21898419
After a few exchanged emails with Sony and some more investigation it seems the problem I'm experiencing is called 'ground loop interference'. I've found plenty of other users experiencing similar problems on a variety of makes of laptop but no solid answers how to fix it. I've found that plugging the monitor and laptop into different outlets seems to improve but not entirely eliminate the problem.
I think I'll just risk running it on a lower rated transformer unless anyone has any insight into the problem.
0
 

Expert Comment

by:sdamon7
ID: 32837670
This turned out to be true, when the power supply was removed from the laptop the external monitor went away.

We solved this by swicthing an old VGA cable with a new VGA cable that had larger Echo Supporesion nobes on the ends of the cable.

The thinking is the larger echos suppresion features on the newer VGA cable supporest the EMF that was being passed onto the extrnal monitor.
0
 

Expert Comment

by:sdamon7
ID: 32837680
IN ENGLISH THIS TIME!  ;)

This turned out to be true, when the power supply was removed from the laptop, the flicker from the external monitor went away.

We solved this by switching an old VGA cable with a new VGA cable that had larger Echo Suppression knobs on the ends of the cable.

The thinking is the larger echo suppression features on the newer VGA cable suppressed the EMF that was being passed onto the external monitor.

It worked!

0

Featured Post

Ransomware-A Revenue Bonanza for Service Providers

Ransomware – malware that gets on your customers’ computers, encrypts their data, and extorts a hefty ransom for the decryption keys – is a surging new threat.  The purpose of this eBook is to educate the reader about ransomware attacks.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Moving your enterprise fax infrastructure from in-house fax machines and servers to the cloud makes sense — from both an efficiency and productivity standpoint. But does migrating to a cloud fax solution mean you will no longer be able to send or re…
Microsoft Active Directory, the widely used IT infrastructure, is known for its high risk of credential theft. The best way to test your Active Directory’s vulnerabilities to pass-the-ticket, pass-the-hash, privilege escalation, and malware attacks …
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…

830 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question