TV repair tips and reviews,tutorials ebooks and tools

It is very important one gets conversant with series of tv panels as this help in correcting some faults most es pecially those brought in for repair but have been taken earlier to a repairer.A customer referred to my workshop brought the tv with a complain that the standby lits only but it fails to start.On checking it,I detect the HOT is faulty and replaced with a new one but alas the problem persist.All the components surrounding the fbt were perfect according to my meter reading.Then I went straight to the eeprom 24co8 and changing it corrects the fault.The tv starts quite alright but I observed that the display wasn't okay and this is because the HOT heats up and becomes very hot.I changed the fbt but still it continues to heat up.At this point I now remember that I have a similiar panel from where I discovered that the value of HOT used by the former repairer was the wrong one and has misled me also.He uses bu808d instead of bu2508af, the readings of these transistors is obviously different and the tv works well as I replace with the bu2508af.

crt television fault repair

horizontal transistor gets hot and blow off

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It is very important for a repairer to be very observant because many atimes the major causes of failure in most of electronics board is dry solder joints.Before and after repairing a board,I will advise you check it very well to make sure all dry joints are resoldered and avoid hurriedly assembling the set as this may give you another problem thereby compounding your work.A good repairer must have a good eye.

electronics component tips

Dry Solder Joints

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posistor

The posistor which is also called Posistive Coefficient Thermistor(PTC) is an electronics device common in almost all television circuit.At room temperature(25'C) it has a low resistance but the resistance becomes high when current flows through it.The posistor works in conjunction with the degaussing coil to give a balance colour on the screen.
whenever there is colour patches on screen,this is a sign of defective posistor.A short in degaussing coil can also result to a dead circuit.

electronics component tips

The Posistor

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There is this television brought to me over the weekend-a medion 14'' Tv-when you power it the standby light is on but it fails to start.Checking the power circuit the components are fine from my meter readings though,less emphasis should be placed on the power circuit for this type of fault.The main focus should be on the reset circuit and the secondary side of the SM transformer.Let me state here that you need to master how to take voltage readings(most especially dc volts) with your reading meter because this fault requires tracing dc volts to correct it.I took my dc volts reading at horizontal output and it gave me 110v which is okay .Same apply to all the volt supply from the secondary side of the switch mode transformer,that is the 25v,16v........and since the readings from the reset circuit tells me the components that constitute it are fine, the next suspect is the memory ic and it is always located near the microprocessor(system ic).This tv has a 24C08 ic.and immediately I changed it and powers the tv,it came on and was working perfectly.

eeprom ic related fault

faults related to memory ic in television

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Let's consider how to repair a dead dvd power supply and an example of a type of dvd supply is shown above sourced from electronicsrepairguide.com.what will be observed is the fuse may have get blown.I will advise you don't change the fuse immediately because doing so without first of all checking for defective component in the circuit can wreck a great havoc in the supply.What you need to do before replacing the fuse is to range your multimeter to x1 ohms range and take readings at the terminals of the power capacitor.If your readings tends towards zero in both direction that means some components are defective so it is better you check and replace them before the fuse will be replaced.One common problem that is related to this supply always has to do with the control ic. when it short circuit-due to high voltage or power surge-it will blow the fuse,so you can source for a replacement at an elctronics spares shop.The bridge rectifier diodes also can be a problem ,take readings of these diodes so as to be sure they are in good condition.If after all these you take readings at the terminals of the power capacitor and it reads short circuit again, definitetly the capacitor will need to be replaced to correct the fault and put the supply in good working condition.All this while what I've been talking about deals with the primary side of the sm transformer.In the next post I will discuss faults related to the secondary side.

dvd player repair

How to repair a dead dvd power supply

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Power faults remains one of the most common faults when it comes to electronics.It may be due to power surge from ac supply ,high voltage or when a component fails at the power stage.What will be noticed is that the fuse will get blown and the mistake we normally make- especially beginners in the field of repairs- is to just change the fuse and power the set.This may result to greater damage of the power supply so it is better to check other components in the supply before deciding to replace the fuse only.Usually when there is a short circuit there is bound to be problem,you need to check for short circuit at rectifier diodes or power capacitor which are the major causes of blown fuse.In this series I will be examining different power supplies and how you can troubleshoot them.

dvd player repair

How to troubleshoot dead power supply with ease.

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A friend of mine brought an Akira 14'' colour tv for repair with the above mention fault.Atimes it will take 30-40mins before the raster comes on and after about 4mins it will fade away with the standby light still on.
I discovered dry joints on the panel board and resoldered it.The raster came on immediately I switch it on but fade away again within 5mins.This fault always connect with the video board so I also check for dry joints and resolder it but the problem persisted.That is it with repair,you need to have a persistence spirit to be a good repairer and if you have professionals around it will hasten up your learning.There is hardly any fault you may encounter on your repair work that someone somewhere hasn't pass through and sharing it with them will help a lot.
Back to what we are treating,I checked +180v supply to video board,it was there.I hold on to the board tightly and noticed the raster came on and fade away as I leave it.This is a sign that the tube base is having problem.As the tube base was replaced with a new one the fault was cleared and the raster came on for more than an hour without fading away.

crt television fault repair , standbylight lit only

Akira TV fails to raster with standby light on

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An improvement in technology had made repair work easier.Gone are the days when troubleshooting takes a long time and bore before a fault can be corrected due to complexity of panel.Nowadays,it seems more easy and fun to repair.we are having devices when disassembled are divided into modules internally,what you need is to identify each section and there functions are, so when there is a fault you will know where to go.If the repair seems difficult you can go to the market buy the module and replace the faulty section to bring your device back to its normal operation.
Apart from making repair easier,it makes it more rewarding in terms of the pay.If you repair very well you will understand what I mean.What you need is to improve on your skill because the more you can repair determine what enters your pocket.
At neyod-repair,we will be sharing repair tips from time to time.If you have a repair tip or faults tending to be difficult feel free to post it.until then ,stay cool.

Repairs in today's technology

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