REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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Tuesday 26 February 2019

SAMSUNG KS-1A CHASSIS TV USES IC SPM802ER / SPM 802ERN MICROCOMPUTER JUNGLE [NO POWER]

SAMSUNG KS-1A CHASSIS TV USES IC SPM802ER / SPM 802ERN MICROCOMPUTER JUNGLE [NO POWER]


As set is dead, troubleshooting must start with main power regulator section

    The main power switching IC used with these sets is [KA 500765]. Only two output voltages are taken out from SMPS transormer.  112VDC and 16VDC. 

    Check the mains fuse.

 If found blown out, check [CX801S-0.22MFD] and overvoltage protector SNR [YX 815-SVC7510-10A].  to this model set, even the main ON/OFF switch is set OFF, the AC supply will come tto above said two components.  If a lighning or sudden line over voltage occur, it will effect these two components, if main control switch at the wall power outlet is not switched OFF.

    Desolder out [NT 802S - 4.7Ohms] thermistor from circuit.  this will isolate the switching section STR and all other components. Check all the four rectifer diodes [D803S, D802S, D804S&D801S] for short.  measure the reverse resistance to these diodes by an ohm meter.  If found leaky, replace them.  It is best to replace them all at one time. Check [C808 - 1000PF 400V] too. A leaky capacitor will also be the cause or blown up fuse.  If all of the above components are OK, desolder one end of [L802], which in turn supply voltage to drain lead of the power switching controlled MOSFET.  Now measure the resistance between pin number 1 [Drain] and pin number 2 [Source] of the internal MOSFET of the switching regulator.  the resistance to these two terminlas must be very high.  If found low or measures apporximately equal to zero Ohms, the power switching regulator IC [IC 801C],  is faulty.  It should be replaced with same number.
But, before replacing this component, chak all the other components connected to this switching device.  Desoler out the swithcing IC from circuit and check each component. Check zener diodes DZ 803- 27V & DZ 805- 18V] for any damage.  It is best to replace these two zener diodes.

    There are nothing more to chek in special, as the power swithichg regulator section of this model is much simple to troubleshoot related to other color TVs power supply section.

If main rectifer diodes [four of them said above] found shorted, it will be best to replace C801 - 220MFD 400V] (Main filter cpacitor),  and [PC 801S - PC 123Y], the optocoupler, even they measures OK.

The two output voltages from this power supply section are 112VDC; at cathode of [D805 - RU2GA] and 16.6VDC at the cathode of [D807 - RU20A].