Haier color TV 34P-9AT after the fire strange maintenance example - Appliances

Single chip microcomputer STM32L151CCU6
Filter 18.432M
SMD aluminum electrolytic capacitor

Model: Haier color TV 34P-9AT
Fault: Suddenly a few clicks during the play, the result is "three nos"
Overhaul process: 300V filter capacitor is detected first with 100Ω file, charging and discharging are normal, indicating that the power supply thick film N501 is basically nothing. Then check that the resistance between the three poles of the V450 is 0, indicating that the line has broken through the short circuit, replace the line tube, and look closely at the outside of the high voltage package, and there is no trace of fire. For safety reasons, disconnect the high voltage package + B pin, check +B130V, normal, use 2.5A file to monitor the line current, start up, only see a discharge near the high voltage line of the deflection "啪", immediately disconnect the pen off, pull The high-voltage line only sees a small pinhole shape, which seems to be caused by the quality of the high-voltage line.
Carefully cut with a blade, attach silicone, and wrap N-layer tape. Turn on the light, the filament is bright, with the sound, think it is done, but the screen is a horizontal bright line.
Measurement field output IC (N301LA78041) working point, power supply is normal, the excitation input pin voltage is 0, the floating signal input pin (1 pin), the measured ground resistance value is also 0, decisively replaced 78041, the startup fault remains, the signal input pin Still 0V.
The machine is a super single-chip, CPu, decoding, scan set as one, the model is: HAIER8829A-V1.0, it seems that the manufacturer's self-written mask chip, it is estimated that the market is difficult to buy. Download the circuit diagram to view, the field excitation output is the 16th pin, and the measured resistance value is 0 in the road, indicating that the IC has been made ancient. Contact us at Haier for sale, but there are goods, each piece of 75 oceans (later to Taobao search, the most expensive is only 45 yuan), rushed to buy back, the result is that the TV is still not giving the same face "the same moonlight, the same smiley face The same me and you..." Is it not good to buy new pieces? Measuring 16 feet, 3.6V excitation voltage is already available, the output pin of LA78041 is also reduced from the original cutoff voltage of 23V to 13V, the field output has been working normally, but why is it still a bright line? Is the fire close to the deflection and break the deflection coil?
Measuring the deflection DC resistance, 10.3 Ω is normal, and the deflection plug is also measured, and it is strange!
Unintentionally check the field correction resistor R329 (180Ω), the universal meter shows 180Ω! This is parallel to the deflection coils, the resistance of the normal deflection coil, it seems that the printed circuit is broken, and sure enough, the line that deflects the pin to the correction resistor is measured as a large resistance (online detection), as follows The figure shows:
QQ screenshot 20111102210201 Haier _ copy.jpg
The broken line is very concealed. If you don't look carefully, it's hard to see, cut off the paint, solder it, and start it all OK!
There are three problems, I hope that the experts will educate us:
1. After the fire, the field output IC does not short-circuit the output end but breaks through the signal input terminal?
2. After the high-voltage ignition, why does the CPu part of the single-chip microcomputer not be smooth and the partial scanning part is broken?
3, the printed circuit has been fired and broken (indicating that it is already high voltage and high current), why does the field output IC not burst?
Everyone is welcome to have a heated discussion, and the show will give extra encouragement! thanks for reading.

Din41612 Connector

Antenk DIN41612 Connectors are a versatile two piece PCB connector set with feaures useful for many applications including connections for plug-in card and back-panel wiring, PCB to PCB attachment and peripheral connections for external interfaces. Features include a multitude of body sizes and styles with options that include selective contact loading, make and break contacts, contact lead length choices and contact plating variations each in .100" [2.54mm] or .200" [5.08mm] centerline spacing.


The DIN 41612 standard covers a series of two-piece backplane connectors widely used in rack-based telecommunication, computing, process control, medical, industrial automation, test and measurement and military/aerospace systems where long-term reliability is required. They consist of one to three rows of contacts in combinations of 16, 32, 48, 64, or 96 contacts on a 0.1-inch (2.54 mm) grid pitch. The 3 rows are labelled a, b and c and connectors up to 64 way if using a 96 way body can use either rows a+b or a+c. DIN 41612 Signal connectors can be rated to 1.5 amps per signal pin, at 500 volts, although these figures may be de-rated according to safety requirements or environmental conditions. Several hybrid power and coaxial configurations are available that can handle up to 5.6A or even 15A. This wealth of variations explains the very wide range of applications that they`re put to. For over 30 years these DIN 41612 `Euro Card` connectors to IEC 60603-2 have offered a highly reliable system for board interconnects. Precision contact density, low mating forces, a two piece protective design and many contact termination styles offer unlimited design opportunities. Termination methods include – straight PC, solder eyelet, wire wrap, crimp and [press fit" terminals. Insertion and removal force are controlled, and three durability grades are available. Standardisation of the connectors is a prerequisite for open systems, where users expect components from different suppliers to operate together; ept and Conec DIN 41612 are therefore fully intermateable with all other similarly compliant products from other manufacturers like Harting, Erni, Hirose and TE Connectivity, etc.

The most common connector in the DIN product line is type C, which is widely used in VMEbus systems, the DIN 41612 standard has been upgraded to meet international standards IEC 60603-2 and EN 60603-2. In the past, ept used a comb supported press-fit tool for their type C and B press-fit female connectors. To be more competitive, ept has changed to flat-rock technology (just a flat piece of steel pushed on the top of the connector) as used by many other manufacturers.


DIN 41612 Connectors are widely used in rack-based electrical systems. The standard performance of these connectors is a 2 A per pin current carrying capacity and 500 V working voltage. Both figures may be variable due to safety and environmental conditions.

Types
Number of contacts varies
Many variations of housing material, including different types of metal and plastic
Both angled and straight versions
Male and female

C,R,B,Q Type DIN41612 Connectors

C R B Q Type
Half C, R, B & Q Type DIN41612 Connectors

Half C R B & Q Type
1/3 C,R, B & Q Type DIN41612 Connectors

1 3 C R B & Q Type
H, F, H+F & M type DIN41612 Connectors

H F H F & M type
IDC Type DIN41612 Connectors

IDC Type
Female Cable Connector

Female Cable Connector
High Pin Count DIN41612 Connectors

High Pin Count
Shroud DIN41612 Connectors

Shroud

Features and Benefits of Din41612 Connector:
• Indirect mating (male/female)
• Automated production processes
• Continuous quality assurance
• 3-160 contacts
• Complete interconnection system
• Numerous interface connectors
• A wide variety of hoods
• Many termination technologies provide for the lowest installed cost
• Contacts selectively gold-plated
• Tinned terminations for increased solderability


Uses
The primary use of DIN 41612 connectors are PCB Connectors and motherboards, the main acceptance would be their board to board reliable connections.

Applications of Din41612 Connector:
Applications
• Data centers
• Storage
• Servers
• Base stations
• Telecommunications equipment
• Backplane and motherboard assemblies
• Switching systems
• Modular rack systems
• Power automation
• Distributed control systems in
industrial control
• Programmable logic controllers (PLC)
• Robotics
• Test and lab equipment
• Energy distribution
• Monitoring equipment
This is not a definitive list of applications for this product. It represents some of the more common uses.


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