Repairing the power supply to the integrated PWM controller STR10006

Repairing the power supply to the integrated PWM controller STR10006




Power supplies to the PWM controller STR10006 widely used in
inexpensive video equipment, but because of its low reliability often
come in for repair, the article discusses how to repair them and how to
improve their reliability,
Video recorders and video players firms Goldstar (LG), Akai, Sharp
and many others with the power supply to the PWM controller STR10006
very common among users of video technology because of its simplicity
and low cost. Unfortunately, power supplies, these devices very
unreliable.
Poor ventilation housing with very tight mounting elements on the
board the power supply becomes hot. Prolonged exposure to high
temperatures leads to loss of capacity of electrolytic capacitors and as
a consequence - to the fuzzy start pulsed power supply or an excess of
output voltages. The latter is often the cause of failure of expensive
electronic components VCR, in particular the driver motor control drive
shaft, load and unit heads.
As an example, consider the circuit power supply video player Goldstar P-R500AW (Fig. 1).

[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]
In most cases, power supply circuits made on the controller,
STR10006, like the examples in this article, except in the scheme of the
secondary rectifiers. In some video unit integral stabilizer on 6 is
located directly in the power supply, and some - on-board recorder or
video player (Samsung VQ-31R/R10).
When repairing these recorders, especially vehicles that are more
than two years, preferably immediately replace the electrolytic
capacitors SR06 (2,2 uF, 200V), SR11 (47 uF, 10 V), SR12 (100 uF, 10 V)
in the primary circuit of the power supply new ones. A decrease in
capacitance SR06 power supply ceases to run at reduced capacitor SR11
and SR12 increased secondary voltage. Better to install capacitors from
the temperature of 105 ° C.
If the repair process revealed that the integrated PWM controller
STR10006 out of order, then it is better to replace STRD1806. He is a
bit expensive STR10006, but much more reliable and surpasses it in the
parameter.
In the secondary circuit produces two voltage: 6 V and 16 V. In
shestivoltovoy chain is an integral regulator ICP02 - KIA7806P, so even
with an increase in input voltage due to the drying container is not
going to increase the output voltage. But the voltage 16 V in case of
emergency may greatly exceed their face value.
This voltage is routed directly to the board recorder. To protect
circuits from overvoltage in case of emergency is a protective Zener
ZD102, which is the breakdown closes the circuit 16 and thus carries the
power supply into a protective mode. But often Zener simply terminates
and increased tension comes at a fee system, which leads to sad
consequences.
To protect circuits from overvoltage tape is suggested that the chain
16c integral stabilizer 142EN8b domestic or imported KIA7812. In this
case, the output voltage in case of emergency can not exceed 12V.
IC regulator it is best to install on an extra radiator and fix it
directly on the shell near the power supply output terminal. You can
connect it instead of the inductor LP02.
In conclusion I would like to advise all owners referred to VCRs not
keep them in standby mode, ie turn off the unit from the network when
you do not see or do not record the movie. This much you extend the life
of your VCR and save yourself the trouble of repairing it.