Question about Cornerstone Computers & Internet

1 Answer

7540 Compaq Monitor : Dry solder joints in Horizontal.

My Compaq Monitor 7540 failed to show on screen.
I removed cover, and found three dry solder joints on the main board.
I was able to repair the first time, and it operated OK.
It has happened again, but this time after soldering four dry solder joints, it will not operate this time.
Is there any chance of a circuit diagram of this model, as I would like to repair if possible.
Possibly the H/output transistor or other may be the fault, but on mentioning it to the electronic retailer, they was not able to offer what the transistor was when I asked for a C 5929 to replace it. It may not be the answer, but I would like to give it a try, and also other components that I might suspect.
Would be pleased if transistor equivelents are able to be idendified so repair may be able to be performed.
Where I am situated at the Gold Coast in Australia, there does not seem to be the knowlegeablepersonel that I was familiar with in the Southern States, so am a bit handicapped.
Thanking you, for I was quite happy with the Monitor when it was operating correctly, and am able to repair myself as I was an electronic technican a few years ago.
Allan Lomer.

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

The best solution was to throw it out, and purchase a new LCD model, of another brand, as I expect there would be more troubles in the future with the Compaq model, seeing that this is the second time that dry solder joints have appeared in the two years I have had the monitor.

Posted on Feb 06, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Blank screen when pushes it comes again after 2 min same problem


This is a fault solution which can be checked and corrected by you assuming that there is no component failure. There is a high possibility that the components over a period of heating and cooling, tend to bring on a problem of dry soldering. So my advice is to check the set for some loose joints that have played on to give you these erratic shut downs or poor performance. The best way to check for loose connections is to tap lightly when the set is powered on, if there is change while tapping then it seems that there are DRY solder joints. Remove main plug, the covers - with caution of high voltage, check for dry joints, and use a good soldering iron to solder all suspected points. Sometimes the fault occurs when the set warms up; if so you can simulate the heat using a hair dryer on the suspected areas, try with the power supply, distribution, Processor controller, driver controllers on the A/V related sections. Also the use a FREEZE-IT spray can simulate the components to cool and show up the fault. It can also be related to WEAK ELECTROLYTIC capacitors as the value can reduce in time. Based on the above method you must be able to locate the area of fault and solder the sections.

Dec 10, 2011 | Philips Standard 107S 17" CRT Monitor

1 Answer

Screen keeps turning black


This is a fault solution which can be checked and corrected by you assuming that there is no component failure. There is a high possibility that the components over a period of heating and cooling, tend to bring on a problem of dry soldering. So my advice is to check the set for some loose joints that have played on to give you these erratic shut downs or poor performance. The best way to check for loose connections is to tap lightly when the set is powered on, if there is change while tapping then it seems that there are DRY solder joints. Remove main plug, the covers - with caution of high voltage, check for dry joints, and use a good soldering iron to solder all suspected points. Sometimes the fault occurs when the set warms up; if so you can simulate the heat using a hair dryer on the suspected areas, try with the power supply, distribution, Processor controller, driver controllers on the A/V related sections. Also the use a FREEZE-IT spray can simulate the components to cool and show up the fault. It can also be related to WEAK ELECTROLYTIC capacitors as the value can reduce in time.

Nov 29, 2011 | Acer AL2016W 20 inch Monitor

1 Answer

I am having LG 700E CRT Monitor, my scree is shaking means, the screen goes up either goes in the middle but if i just shake the monitor with my hand than some times it works fine


This is a fault solution which can be checked and corrected by you assuming that there is no component failure. There is a high possibility that the components over a period of heating and cooling, tend to bring on a problem of dry soldering. So my advice is to check the set for some loose joints that have played on to give you these erratic shut downs or poor performance.The fault seems to be with teh VERTICAL DRIVE SECTION, possible that the vertical IC is having DRY SOLDERING.

The best way to check for loose connections is to tap lightly when the set is powered on , If there is change while tapping then it seems that there are DRY solder joints. Remove main plug, the covers - with caution of high voltage, check for dry joints, use a good soldering iron to solder all suspected points.

Thank you for using Fixya.

Sep 16, 2011 | LG Studioworks 700S 17" CRT Monitor

1 Answer

When I turn on my computer my monitor turns on and off in 5 seconds appears on the screen and it goes to stand by mode and no picture ever comes on the screen


This is typical with many sets when it goes old as there is a high possibility that the components over a period of heating and cooling , tend to bring on a problem of dry soldering. So my advice is to check the set for some loose joints that have played on to give you these erratic shut downs.

Remove main plug, the covers - with caution of high voltage, check for dry joints, use a good soldering iron to solder all suspected points.

Jun 25, 2011 | Computers & Internet

1 Answer

My monitor on and off repeatedly....and it keeps doing it


This is typical with many sets when it goes old as there is a high possibility that the components over a period of heating and cooling , tend to bring on a problem of dry soldering. So my advice is to check the set for some loose joints that have played on to give you these erratic shut downs.

Remove main plug, the covers - with caution of high voltage, check for dry joints, use a good soldering iron to solder all suspected points.

Jun 17, 2011 | Computers & Internet

1 Answer

My compaq monitor just start blinking and now only haft past of the screen is visible. the rest just went black with on bright shining line on the middle of the screen


hi,
Your monitor have problem with vertical deflection section. Can caused by the faulty vertical driver IC and faulty electrolytic capacitor it the vertical section or dry soldering in the pins of the vertical driver IC. When vertical section fails horizontal lines come on the screen. For testing the same you have to open the monitor and remove the main board. you can easily find out the vertical ic. just follow the four wire running from the deflection yoke ( coil on the crt neck) of which two will go to the horizontal section (normally red and blue wire) and two will go to the vertical section ( Normally yellow and green wire). Follow the yellow and green wire which will be connected to one of the socket in the main board. Follow the circuit track in the main board which will lead you to the vertical deflection section. There you can see one ic is fitted on a aluminium heat sink.Take a close watch in soldering of its leads. Dry soldiering can happen in its leads because its a component which will got to a temperature about 75 degree above at its normal working condition. if found any dry-soldering or not just resolder all the pins of that ic. then check the monitor. If problem remains then you have to relapse the ic.While replacing the ic try to relapse all the capacitors in that section. It will prevent from any further damage to the new vertical ic. if you need any more assistance feel free to contact me through fixya

Jun 09, 2011 | Compaq P 1220 22" CRT Monitor

1 Answer

I was given a Soyo monitor, model; DYLM1988, that starts but only stays on for a few seconds. What are some possible problems and what could I try to fix it?


This is typical with many sets when it goes old as there is a high possibility that the components over a period of heating and cooling , tend to bring on a problem of dry soldering. So my advice is to check the set for some loose joints that have played on to give you these erratic shut downs.

Remove main plug, the covers - with caution of high voltage, check for dry joints, use a good soldering iron to solder all suspected points. Please find below two links for tips on poor start ups, as if the set is totally failed the SMPS might be faulty


Soldering tips:


Slow start of circuit

Nov 16, 2010 | Soyo TFT 19" LCD Monitor

2 Answers

Red screen


it is possible that solder joint at the back of the tube is dry.
resolder it.
Have a try
TIA

Apr 13, 2008 | Compaq FS7600 17" Flat Glass Monitor

1 Answer

Compaq 7540 colour looses red color


check the pin # 1 of video input cable { broken or Bent }
if it is ok then there must be a problem with the cable or RGB Processing Circuit { Normally Dry Soldering of a faulty IC in the circuit of CRT BASE} .

Mar 09, 2008 | Compaq CV 7500 17" CRT Monitor

4 Answers

Display green,red


It should be dry solder joints on the CRT board,the picture tube base is normally dry solder.
Opening the monitor could be tricky as there are two plastic locks which hold the top end of back cover.
Samir

Mar 09, 2008 | LG Studioworks E700B 17" CRT Monitor

Not finding what you are looking for?
Computers & Internet Logo

Related Topics:

171 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cornerstone Computers & Internet Experts

Brian Sullivan
Brian Sullivan

Level 3 Expert

27725 Answers

kakima

Level 3 Expert

102366 Answers

David Payne
David Payne

Level 3 Expert

14161 Answers

Are you a Cornerstone Computer and Internet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...