TYPICAL TROUBLESHOOTING OF TV "AKAI"

1). AKAI.

No sound. Check from the LF input, if the sound appeared and adjusted, turn on the automatic station search mode, if the search does not stop at the caught station, or the program number does not change, then the processor does not receive the station identification signal. Of course it's good when there is documentation, if there is no documentation, if there is not, or if there is not time to search, I do it: by exclusion, I exclude those legs of the prots who do not participate unambiguously in this process (this is 80 percent), alternately measure the remaining unknown conclusions eg. When translating TV into dir. LF inputs and back, fix while those on which there is a change (usually 2-3 not more), then they alternately opayivayu from the scheme, the sound will appear, this can be limited to if the toad presses to change something or a little bit further on the board climb. The truth is there will be no sound blocking when the signal disappears and the car. Settings.

2). AKAI- (CT-21 (14) 07D).

Defect - when switched on from the standby mode, the LED goes out and then lights up again. The zener diode has a 12V power supply of the radio channel. Power from the stitch, near him naturally bursting the tensile resistance. When everything is eliminated, do not forget to check the C-meter electrolyte in the 47μF-16V power supply, because Power supply Recorovskogo poshiba. The defect is common. Then the most interesting. The defect of the Funai processor was written expensive, and what to say about the defect of Akai - it is 2.5 times more expensive. It manifests itself with warm-up, after half an hour-it turns off into standby mode or the reception disappears, there may be a chasm in advance. You can change it to any one of C68224, 230, 241. If there was C68224, the replacement at 230, 241 will lead to an increase in the setup time and only that it can be treated if desired, but it does not arise.

3). AKAI CT-1407 DT.

The TV does not turn on. The output voltage is too low. When you connect to the TV, the MP 3-3 works fine. Fault in the felting condenser but not in that of 115 volts, but in that by 18. They checked the instrument instead of 220 ICF there were only 16 ICFs. A good defect.

4). AKAI 21.

Often the following breakdown occurs: 1. The parametric power regulator of the AN5601 chip is out of order. This is due to the fact that the electrolytic capacitors in the power supply unit of the TV 47μc dry up, which causes an increase in the horizontal line voltage, which leads to the failure of the zener diode that is part of the parametric stabilizer. Eliminates the failure by replacing the resistor, which is serially connected to the power circuit of the AN5601 chip on the 7812, and the zener diode is completely removed. Both capacities in the power supply unit should be replaced by 100 microns 63 volts. 2. This same failure is due to the failure of the tuning resistor in the power supply of the TV. It should be replaced with a more reliable one.

5). AKAI CT-1407DT and on TVs with similar power supplies, such as REKOR.

All the symbols on the diagram correspond to the reference book "ALBUM SCHEMES FOR FOREIGN TV. 3-RELEASE '' moscow1995, scheme Akai CT-1407DT, p.4. I want to draw your attention to the fact that the manifestation of a breakdown can be very different! This is the absence of line scanning (breakdown of a line transistor), the absence of a vertical scan (IC401 output and its power circuits), the breakdown of the split-transformer insulation, and even once was the loss of the kinescope emission. When eliminating the above-mentioned, and many unnamed breakages, the TV worked like it would be normal (sometimes a bit too much in size horizontally), but after some time (sometimes in 6-8 months) it broke again. The breakdown could be absolutely different. The cause of the failure is C011 (a 47μf-50v capacitor coming from the base of the transistor of the power supply unit.) During operation, the capacitor gradually loses its capacity (it dries out?), Which gradually increases the output voltage of the power supply unit. In the event that you try to repair a TV with a similar power supply, I recommend immediately checking the power supply voltage (in this case on D401) of the line scan. If you do not correspond to the modes indicated on the diagram, change C011 boldly. This breakdown was approximately in 80% of broken TVs with similar power supplies.

6). AKAI 14-21D.

To the advice already published by the Internet on replacing the broken-down zener diode with 12 volts (power supply to the video processor) to the 7812 stabilizer and refuting to what should not be done, that the zener diode is likely to perform the function of protection. Literally the other day I came across a TV with a stabilizer set instead of 12v V 7812. Fault in the following: the overvoltage supply voltage is 176 VOLT, and hence the overstated all secondary sonic sweeps, so the power supply voltage of the video amplifiers was 295 VOLTS instead of 195. Further breakdown in the kinescope gap, the TDX melted and had an internal breakdown. Malfunction in the BP due to the already famous condenser 47/50. So it is not likely, namely, the zener diode performs the role of protection, and if the BP fails, in case of increased supply voltage, it breaks thereby blocking the operation of the scanning cascades. A zener diode would be installed; Then if you do not prevent a second repair, the cost would be an order of magnitude lower.

7). AKAI CT-2107DT, CT-2107D.

When replacing the C68224 processor with the C68230, the TV should be refined: R637 33Kom replaced with 6,8Kom, R619 100Kom replaced with 1 MOM, R653 56Kom replaced with 10KΩ, R654 56Kohm replaced with 33KΩ, C631 10uF replaced with 47uF, it is still necessary to install a jumper on the board Which is signed as "C". The first aperture of this jumper is next to the transistor Q11 second near the resistances R637, R619.

8). AKAI.

After warming up, after an hour, the tuning for the channel disappears. This fault has been described here. I managed to cure the TV by installing over the processor on the racks of wire 1.5 mm fan from the computer processor. Power fan 12 V. This repair is about 10 times cheaper than CPU replacement. The only inconvenience is the small noise of the fan - it's audible with a completely clean sound. The TV works for about 6 months without any glitches.

9). AKAI CT2107D.

The TV does not turn on. Defective power supply, capacity C917 - 100mph. 160 volts exploded, protective zener diode ZD401 at 12 volts probit, resistor R421 on the precipice. After replacing all the parts, the TV was switched on, instead of the load, a 220 volt 60-volt lamp was connected. When measuring the voltage in the secondary circuit, instead of 115 volts, there were 210 volts. The electrolyte C911 is 477 cc. 50 volts. (Instead of ZD401 at 12 volts, installed KREN8B, is included instead of the resistor R419 - respecting the input and output).

Note: instead of a zener diode on 12V, you can not put KREEN8, because The zener diode is protective and, when the horizontal line power is too high, it breaks through and disconnects the 12V circuit, which causes the line to stop. And so it is fraught with a breakdown of the line transistor (at best, and in the worst TDX), because The crook tries to stabilize only 12v to the last ...

10). TV AKAI CT2107D.

A classic defect in TV burns a protective zener diode on 12V in the power circuit of the video processor, the resistor breaks and sometimes the transistor of the horizontal scan burns, the cause is the loss of stabilization of the PSU. You can simply replace the failed parts, and in the power supply, replace both capacities 47μf 50v by 100mph663v. Over 300 TVs were repaired.