electronics, repairs, service manuals and datasheets discussion community for the repairs professionals and technicians
FAQSearchMembersGroupsRegisterProfilePM'sLogin/Out
monitor switching on and off repeatedly

 
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Equipment Repairs
View previous topic :: View next topic  
Author Message
beexo
Guest





PostPosted: Fri Nov 18, 2005 8:16 am    Post subject: monitor switching on and off repeatedly Reply with quote

Hello!

I have a monitor Daewoo 431X that is constantly swithching on and off. During the time that it is switching on, resistor R525 is glowing red hot. Resistor R321 also seems to be burnt. I do not have schematics for this monitor, so I don't know their resistances.

Can anyone help with this repair? I will pay for a service a service manual if it's not too expensive.
Back to top
sparky



Joined: 18 Nov 2005
Posts: 98
Location: U.K

PostPosted: Fri Nov 18, 2005 9:33 am    Post subject: monitor switching on and off repeatedly Reply with quote

Although I don't have a service manual their is obviously a short.
Measure resistance of collector of the line output transistor to chassis and see if short and remove it, test and try powering the set to see if still glowing. If not measure the voltage at the collector pad (transistor is out of circuit). If voltage is o.k or nolonger glowing then line output transistor and/or transformer may be shorted.
The reason I said maybe a voltage is sometimes (depending on circuitry) the power supply will not start with line output disconnected as feedback or a load is required.
For a load I normally use a 60W light bulb.
Try this first.
_________________
If in doubt pull the plug out.
Back to top
View user's profile Send private message
Guest






PostPosted: Sun Dec 24, 2006 9:30 am    Post subject: Re: monitor switching on and off repeatedly Reply with quote

beexo wrote:
Hello!

I have a monitor Daewoo 431X that is constantly swithching on and off. During the time that it is switching on, resistor R525 is glowing red hot. Resistor R321 also seems to be burnt. I do not have schematics for this monitor, so I don't know their resistances.

Can anyone help with this repair? I will pay for a service a service manual if it's not too expensive.
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Electronic equipment repair and service manual search discussion Forum Index -> Equipment Repairs All times are GMT
Page 1 of 1

 
Jump to:  
You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


eServiceInfo on FB - Service Manuals Free Download - Service Diagrams

Free TV Schematics Download - HARDW.net - Pinout Master - Jabse Service Manual Search - Jabse.InK  - onTap.bg

SnimkiOt.com - Poblizo.com : пътешествия