Do-it-yourself benq w2108 monitor repair

In detail: do-it-yourself benq w2108 monitor repair from a real wizard for the site my.housecope.com.

Fault: the monitor does not turn on and the power indicator blinks... The malfunction is typical and immediately hints to us about problems in the power supply, so we proceed to disassembly. To do this, unscrew all the screws on the back of the monitor, including those disguised under the caps. The latter are removed easily enough if you pry them. We take out the stand from the mount and unscrew another screw under it.

We pry the case around the perimeter, disengaging the latches. Sometimes you have to use physical force on especially tight latches, but remember one rule - where the plastic goes better, the latch opens there. The power supply and signal processing board are located under the back cover. Unscrew the DVI and D-Sub (VGA) connectors with narrow-nose pliers. Disconnect the keypad connector and raise the metal screen.

On the left is the power supply board, on the right is the signal board. The swollen capacitors are clearly visible on the power supply board (marked in red). Disconnect the lamp connectors and unscrew the power supply board. The yellow condenser is not swollen, but it is close to the radiator, therefore, for prevention, I also recommend replacing it.

It is quite common for electrolytic capacitors to swell when located close to radiators and heating components. The electrolyte in them evaporates under the influence of temperature. As a result, the dielectric gasket dries out and overheating of the container with swelling is guaranteed. After replacing all the containers, the monitor turned on.

Benq E2200HDA on ET0019NA chassis.

Just does not turn on, the indication also does not work:

Video (click to play).

With 99% of these symptoms, you can safely look at the power supply, when dialing, I found the D803 diode short-circuiting, power is supplied to the PO168 through it, after removing the diode, it was found to be fully operational. The dialing of the seventh pin of the microcircuit relative to the case showed its closure. Replacing the microassembly with a similar one (FAN6751), the monitor immediately started working.

Benq FP71E monitor on Q7C4 chassis

When the monitor was turned on, the backlight appeared and immediately went out... It is immediately clear that the problems in the inverter, specifically after getting acquainted with the monitor circuit, Benq determined the reason: transistors Q815 and Q816 2SC5707 are broken, and they burned out due to the electrolytic capacitor C824 0.22mF 160V (see radio amateur advice on how to check the capacitor). A similar problem can occur in the second arm of the Q808 Q809 C826 inverter.

Benq FP71G on Q7T4 chassis (the diagram can be downloaded from the link above).

Display backlight turns off, almost immediately, and sometimes after a few minutes of work. I took the advice of the repairmen and cleaned the backlight wires from the metallized foil (There is a known defect that occurs due to the metallized tape. When the monitor is heated, the tape squeezes the insulation and a breakdown occurs) and washed off the varnish from under the smd capacitors in the inverter circuit, but the problem persisted. Upon further analysis, the circuit revealed a faulty electrolytic capacitor C826. After replacing it, the backlight stopped turning off.

White screen on the monitor screen... On the LCD control board, replace the faulty fuse and dismantle the capacitor C102

Spontaneous switching off of matrix backlight... Bad contact in SN804 connector of the inverter board, blue wire. Take out, squeeze the petals and put back. When a defect occurs, the backlight lamps light up and immediately go out, if you turn off the faulty lamp, the remaining lamp glows longer.

The backlight turns on and off spontaneously.

A defect in the SMD capacitor C841, when dismantled and inspected, it was split from the bottom side. After replacing the monitor backlight worked.

Color distortion. Control panel buttons do not work.

There is a reaction only to the “On-Off” button. If you click on the others, there is no change. The problem is in the EEPROM U4 24C04N.

Monitor does not turn on: The power supply is OK. I tried to replace the EEPROM U4 24C04N, the monitor turned on, but soon froze again. As I found out, the quartz Y1 24.000 was faulty, (How to check the quartz).

Monitor turns off after 5-10 minutes

The power supply has a faulty 3.3V stabilizer IC701 LD1117

White screen... After 15 minutes of work

Defective microcircuit U11 AAT1164 (analogue of max1517). After replacing it with an analog, the microcircuit became very hot, I had to install it on a radiator for prevention, a similar problem often arises in the Benq FP73G monitor on the Q7T5 chassis

The control buttons do not work, everything except the inclusion... The button lock mode is on; to exit it, press and hold the MENU button

No sound... The problem is in the TDA7496 chip, after replacing it, the sound appeared

White screen In these monitors, this failure occurs mainly due to a blown fuse on the AU Optronics M190EG02 board. Usually, in this case, capacitors C11, C12, C13 fail.

The problem is as follows: if you turn off the monitor after 1-2 hours of work, it is more does not turn on, the indicator is off, and if you wait 30 minutes, the monitor turns on again. Replaced capacitor C712.

If the monitor just won't turn on... Lowered supply voltage 3.3V to 2.5V; 5V to 3.3V due to IC601 NCP1200AP40 chip.

The monitor turns off at various intervals. Dark image.

The problem is in the inverter to check the capacitor C822 (in my case it turned out to be split).

The inscription on the monitor Cable not connected

The malfunction turned out to be in the Zener diode D4 (I checked it with a multimeter in the diode test mode, passed it in both directions)

After an hour of work, the control buttons were stuck... The problem turned out to be in the ZD5 in the Exit button circuit.

Does not turn on... Resistor R603 burned out in the power supply, and IC601 NCP1200AP40 microcircuit and IC602 PC123 optocoupler are faulty. (how to check an optocoupler)

Benq FP93GS on Q9T5 chassis

Malfunction - White raster.

Check capacitor C193, transistor Q5 ELM13401CA

BENQ FP557s no response to control buttons

The reason turned out to be in the buttons themselves, namely in autotuning, in this case.

The examination revealed burnt radio components Q743; Q751; Q741; Q753; Q742; Q752; PF751 was replaced with similar or analogs, when turned on, the PF751 fuse was blown again and Q759 broke. Upon further search for the problem, a short circuit was found in the secondary windings of the T753 transformer.

The PF751 fuse and the Q759 2SC5707 transistor are faulty due to the missing first leg of the T751 transformer.

Monitor does not turn on... The power supply is faulty, namely the Q601 P7NK80ZFP transistor, the IC601 NCP1200AP40 microcircuit and the breakage of the R615 R22 resistors and the F601 fuse are broken.

Problems in the inverter board: Q808 transistors burned out; Q809 2SC5707 Q805 FQU11P06 fuse PF801 capacitor C826.

It turns off after a short time, the indicator is off, before disconnecting the white matrix.

Problems in the monitor's power supply, because the output has an unstable voltage, 5V each. The IC601 NCP1200AP40 microcircuit and the Q601 transistor turned out to be faulty.

The backlight flashes on and off... In one arm of the inverter, I found burnt 2SD5707 (pos. Numbers Q808 and Q809) and swollen capacitors C801 C707, C708 between them. The yellow fuse PF801 3A has also blown.

I was offered to buy a faulty benq FP91G for 2t.r. , took it on trial so far. Initially, I assumed that there was a problem with the inverter, since the monitor works for 20 seconds and turns off.
So, after the autopsy, as usual, both c5707 were killed and the conduit between them was cracked. But I'm not talking about that, since the inverter circuit has been plowed enough to me, it may make sense to buy a separate inverter in the store, it costs 300-400 rubles. the choice is great. Dear conference, tell me on what basis to buy, and is there any sense of this perversion.

MAIN IMPORTANT replace both conduits between c5707, the whole problem is in them.
During operation, they heat up and are sealed off (forming a microcrack) and then the c5707 also die.
I put the same denomination but without case (type K73-17), NO returns!
There is no need to change the inverter!
Good luck.

Dear moderator, do not correct the title of the topic, as the discussion moves away from the originally asked question.
Thank you.

You can look for 11P06 (I had these when Monique came for repairs) and 17P06 (I installed these because I did not find the first ones). Everything is working.And yes, check out the Q811 and similar on the other shoulder. On my Monica, the backlight also shone right away, the Q811 case was with a hole. Q805 and Q812 replaced without thinking Image - Do-it-yourself benq w2108 monitor repair