CN1319998A - Self-check method for TV set - Google Patents

Abstract

The self-checking method for Tv includes the following steps: voltage-driving all voltages produced from power source circuit of TV by voltage divider and converting them into digital quantities, CPU is used to judge that these voltages are normal or not; and utilizing CPU to inquire that I2C bus interface level is normal or not, if it is normal, further utilizing I2C bus to judge that the elements and devices hanging on the I2C bus are normal or not, and count the synchronous signals transferred into CPU and judge that they are normal or not, if the check is normal, the detection indication is normal, otherwise the indication is abnormal, so that it can quickly find fault position, can greatly save time and raise working efficiency.

Description

A kind of self-check method for TV set

The present invention relates to a kind of television set detection method, particularly relate to a kind of method of carrying out built in test by television set itself.

At present, existing television set can not detect automatically to the machine internal fault, if the machine internal fault, the designer has only by instrument instruments such as universal instrument, oscilloscopes and carries out fault detect the designer so in the process of a kind of television product of design; The maintenance personal also can only detect the components and parts failure cause by the instrument instrument in the maintenance process that carries out television product, like this, efficient is extremely low, and is very inconvenient.

The purpose of this invention is to provide a kind of self-check method for TV set, make things convenient for the timely judgment processing machine of designer and maintenance personal internal fault, increase work efficiency.

In order to realize the foregoing invention purpose, the present invention carries out dividing potential drop with the various voltages that television power circuit produces, and the ADC port by CPU carries out the ADC conversion then, and analog quantity is become digital quantity, by judging this digital quantity, just can determine whether the height of these voltages is normal;

CPU inquires about I ²The C bus interface, promptly whether the level situation of SCL mouth line and SDA mouth line is normal, to determine I ²Whether the C bus is normal;

If I ²The C bus is normal, then can further pass through I by CPU ²The C bus with hang over I ²Whether the components and parts communication on the C bus is normal to check these components and parts;

Synchronizing signal is delivered on the CPU, this signal is carried out step-by-step counting, compare with standard value then, to check whether synchronizing signal is normal by CPU;

If above inspection is normal, it is normal then to detect indication, otherwise indicate undesired.

In addition, each above-mentioned step testing result is all carried out whether normal indication separately, if undesired, also with code form misdirection pattern.

Because this method is to utilize to have I ²Whether the CPU of C communication standard and ADC mapping function carries out online detection to television set internal circuit operate as normal, during therefore for designer and maintenance personal's servicing machine internal fault, unusual intuitive and convenient just, can find trouble location soon, thereby save the plenty of time, increase work efficiency.

The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments.

The testing circuit fundamental diagram that Fig. 1 adopts for present embodiment;

Fig. 2 is I ²The transformat of C bus data;

Fig. 3 is for utilizing I ²The C bus is carried out the flow chart of communication detection.

Among Fig. 1,9V, 18V, 24V, 115V voltage that television power circuit 1 produces after voltage divider 2 dividing potential drops, are received the analog-to-digital conversion ADC port of central microprocessor CPU 3, and CPU 3 adopts the TMP87CM38N of Toshiba, its I ²C bus interface SCL, SDA hang with frequency synthesising type tuner TUNER 4, correct integrated circuit how much, and model is STV9306, small-signal processing integrated circuit 6, and model is TB1238, beautiful sound NICAM processing integrated circuit 7, EEPROM (Electrically Erasable Programmable Read Only Memo) E ²PROM 8.The line synchronizing signal H.SYNC pin of CPU 3 connects on the H.SYNC line synchronizing signal in the television set.

In the custom menu of television set, be provided with AUTO TEST (detecting automatically) options.After choosing this, by the function conversion key, changeable AUTO TEST ON/OFF (detecting ON/OFF automatically) function.When AUTO TEST ON (automatically detect open), program begins to detect from POWER (power supply) item, detects BUS LINE (bus) and annex thereof, SYNC (synchronizing signal) successively.Testing result is with color and coded representation, and color has two kinds, and the A representative is good, and the B representative is bad, and bad situation can also further use " Q * * " to represent concrete phenomenon of the failure.

A) POWER (power supply)

The ADC conversion is the ADC port that adopts the CPU of Toshiba, and its resolution is 8, and it can be the analog quantity unscented transformation digital quantity, judges this digital quantity by software then, just can determine the height of voltage.

When definite voltage was lower than the standard low voltage value, counter was started working.When AUTO TEST ON (detect automatically and open), show the counting situation, if show " 000 ", represent that then voltage is normal, display color is B; If show " 001 ", then the unstable situation of primary voltage appearred in expression; If show " 002 ", then the voltage instability stable condition appearred twice in expression, and the rest may be inferred by analogy for it, and maximum times is " 128 ".The counting situation betides voltage and is lower than the standard low voltage value, but continuous time should be less than 2 seconds.If voltage is lower than the standard low voltage value time and surpasses 2 seconds, then machine shuts down automatically, and reset counter, can protect Primary Component can not damage like this.As long as the unsettled situation of primary voltage occurred, then this demonstration is always color A, unless low-voltage auto-off.

B) BUS LINE (bus)

The quality of this main testbus and annex thereof.CPU at first regularly inquires about I ²Whether the level situation of C bus interface SCL, SDA is normal, for example SCL, SDA always are low level, and perhaps always the same level all belongs to abnormal situation, have only as CPU to come to the same thing, could determine I for SCL, SDA level that is provided with and the level ratio of reading back ²The C bus is normal.

In Fig. 2, I ²The transfer of data of C is transmitted on serial data line, and each byte must guarantee it is 8 bit long, but for transmitting each time, the byte number that is transmitted but is hard-core.Each is transmitted the back of byte all must follow a response bits (A), and data are at first sent with highest significant position.Its transformat is: CPU at first sends an initial signal (S), after initial signal, must transmit the address of a controlled device, this address is totally 7 bit long, the 8th bit is the transmission direction position (read/write) of data, wherein " 0 " expression main controller sends data (writing), and " 1 " expression main controller receives data (reading).Each transfer of data always finishes with the termination signal (P) that main controller produces.But, if this main controller is wished to hold over bus and carried out new transfer of data, then can at first not produce under the situation of termination signal, send initial signal once more another controlled device is carried out addressing.

Pass through I by CPU then ²The C bus confirms to hang over I according to the following steps ²Whether each device is normal on the C bus:

At first carry out first step S1, to components and parts write device address;

Then carry out the second step S2, judge whether ACK (replying) equals 0, if, then pass the subaddressing, if not, error message then shown;

After passing the subaddressing, carry out the 3rd step S3, judge whether ACK equals 0, if, then pass 8 bit data, if not, error message then shown;

After passing 8 bit data, carry out the 4th step S4, judge whether ACK equals 0, if not, then show error message, if then carry out the 5th step S5 and judge having passed not, if do not passed, then return and retransmit 8 bit data,, then stop to transmit signal if passed, and the indication normal information.

When bus and annex were working properly, BUS LINE Show Color was B.In addition, represent the situation of bus and annex NG (bad) with " Q * * ", color is A.As:

" Q01 " expression: SCL GND (serial time clock line ground connection), promptly SCL (serial clock) is always low;

" Q02 " expression: SDA GND (serial data line ground connection), promptly SDA (serial data) is always low;

" Q03 " expression: SCL-SDA, promptly SCL and SDA are associated in together;

" Q04 " expression: E2PROM is bad;

" Q05 " expression: TB1238 is bad for the small-signal integrated circuit;

" Q06 " expression: TUNER is bad;

" Q07 " expression: how much circuit for rectifying STV9306 are bad;

" Q08 " expression: NICAM is bad;

For the data of particular importance, pass through I ²The C bus obtains actual value, compares with preset value among the CPU, detects its correctness.So just can Guarantee Status can be chaotic, and avoid owing to produce assembling and debugging and be provided with improperly, and error flow now is exemplified below to market:

" Q09 " expression: the small-signal integrated circuit is not TB1238;

" Q10 " expression: IF (intermediate frequency) is not 38M;

" Q12 " expression: IFLEVEL (intermediate frequency level) mistake;

C) SYNC (synchronizing signal)

Whether this carries out step-by-step counting by CPU to synchronizing signal, compares with standard value then, normal to detect synchronizing signal.When synchronizing signal just often, this detects Show Color is B.In addition, show error message, and color is A.

D) AUTO TEST (detecting automatically)

To gathering of first three items detection case, if all no problem, then show " OK ", otherwise show " NG ".

Claims (5)

1. self-check method for TV set is characterized in that carrying out following steps:

The various voltages that television power circuit is produced carry out dividing potential drop, and the ADC port by CPU carries out the ADC conversion then, and analog quantity is become digital quantity, by judging this digital quantity, just can determine whether the height of these voltages is normal;

CPU inquires about I ²The C bus interface, promptly whether the level situation of SCL mouth line and SDA mouth line is normal, to determine I ²Whether the C bus is normal;

If I ²The C bus is normal, then can further pass through I by CPU ²The C bus with hang over I ²Whether the components and parts communication on the C bus is normal to check these components and parts;

Synchronizing signal is delivered on the CPU, this signal is carried out step-by-step counting, compare with standard value then, to check whether synchronizing signal is normal by CPU;

If above inspection is normal, it is normal then to detect indication, otherwise indicate undesired.

2. self-check method for TV set according to claim 1 is characterized in that described each step testing result, all carries out whether normal indication separately, if undesired, also with code form misdirection pattern.

3. self-check method for TV set according to claim 2 is characterized in that described CPU passes through I ²The C bus with hang over I ²Components and parts communication on the C bus, to check whether normal concrete steps are these components and parts:

At first carry out the first step (S1), to components and parts write device address;

Then carried out for second step (S2), judge whether ACK equals 0, if, then pass the subaddressing, if not, error message then shown;

After passing the subaddressing, carried out for the 3rd step (S3), judge whether ACK equals 0, if, then pass 8 bit data, if not, error message then shown;

After passing 8 bit data, carried out for the 4th step (S4), judge whether ACK equals 0, if not, then show error message, if then carried out for the 5th step (S5) and judge having passed not, if do not passed, then return and retransmit 8 bit data, if passed, then stop to transmit signal, and the indication normal information.

4. self-check method for TV set according to claim 1; it is characterized in that checking in the process of supply voltage at described CPU; surpass when allowing time value if be checked through the duration that the supply voltage that needs protection is lower than the standard low voltage value, by CPU with television auto-shutdown.

5. self-check method for TV set according to claim 1 is characterized in that described CPU passes through I ²The C bus with hang over I ²Components and parts communication on the C bus is to check whether normal concrete grammar is these components and parts: for the described I of hanging over ²The significant data of the components and parts on the C bus also will pass through I ²The C bus obtains actual value, and with CPU in preset value relatively, to detect its correctness.

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