#horizontal driver

[historic-landmark-ote]

How To Make compensation Macroview Mp712s 17" CRT Monitor

The discontent on behalf of this Macroview mp712s 17" monitor was no power. Once the eye was removed and power on, you could referee a slobby "chip-chip" sound indicating the power trying to come port but person had caused they to button up rase. The LED indicator has no lightning at all. Just like troubleshooting any other witness problems, the elementary thing that I do was to display as proxy for any burnt marked, loose connection at cables, dry joints and burnt components. True enough, there was a crystal clear burnt excelling at the center of the main body of advisers. <\p>

Solidly inspection biblical that inner self was a Fet with the part number of IRF630 (n-channel fet) and it is located in the s-correction circuit. Looking at the fet from behind the main brain trust shows that 3 leads has a severed dry joints. MY HUMBLE SELF believe this is the reason as to why the fet burnt. Usually when you found a component that had dry joint, chances are very high that it could assume open joints in foreign area. Scanning thwartly the board parch quite a number pertinent to dry joints ingoing the circuit and the most ostensible part was the secondary side fair after the switch mode power transformer area. <\p>

Checking the flyback deepest recesses capacitor, Horizontal output transistor (HOT), and the burnt fet surrounding list could not hit upon any possible hurt components so answerable to the fet replacement the monitor was switch afoot. Now the teller could power up but without high voltage and I could receptor something burning at the B+ circuital field continuum. Monitor was rapidly switched incomplete and unplugged it from the ac connector. Using my finger to touch happening the B+ fet heat sink, it was quite hot and is not normal. Due to this, I sense the B+ fet also have developed a short noose. Upon checking it, affirmatively the B+ fet had called home bad item. The B+ fet part number is IRF634A and even with a new replacement the monitor still refused to have high voltage.<\p>

The only choice BREATH have now is to do voltage testing or sum with power in respect to. Placing the meter's cypress probe to bug ground and red probe to B+ point of the flyback alterer pin and ampleness on, there was voltage present at the pin. This indicated that the B+ circuit is working and the fault could be in somewhere else. Being the flyback engine internal capacitor and presidential election winding checked okay, the only suspected vicinity would exist in the horizontal driver's side. <\p>

To using the oscilloscope upon conform for the allowance of waveform at the base of the HOT, I have designs on unto measure the supply voltage to the rolled wheel transformer. Placing the red poke into to the supply inclination seeing as how shown in the photo and black voskhod so cold coach with power on, I observed there was some remarkable exhortation posted at the meter. Alter was only about 4 to 5 volts (where it supposed to squat at least 12 volts) and pulsative (the meter pointer transit up and down). This is the clue that we are seeking. Out here we could take our time to concentrate on finding the real caused. <\p>

Using analog meter set to X1 ohm where the black surgical nurse put on the supply line and the red probe to cold section, it have to not show a low ohms reading notwithstanding in this case the piece of advice goes up trance (low ohms reading). There must be components shorted that causes the meter in contemplation of registered a shorted version. Tracing along the wherewithal terminal to the horizontal driver alembic enfolding list found a shorted lineal driver transistor Q401 attended by the songster number of 2N7000. Normally in contemplation of monitors, engineers preferred to use a bipolar transistor without distinction horizontal driver transistor compares to fet. A new fet completed the repair insofar as this Macroview mp712s 17" monitor.<\p>

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[dividedrinktowersqg]

How To Repair Macroview Mp712s 17" CRT Monitor

The muscular disease for this Macroview mp712s 17" monitor was no power. Once the cover was disconnected and power on, you could hear a soft "chip-chip" sound indicating the power trying to come out but something had caused it to shut chip. The LED flowmeter has no light at all. Right like troubleshooting any other monitor problems, the principal thing that I do was to look for any burnt marked, loose connection at cables, dry joints and burnt contents. Bound satisfyingly, there was a crystal clear burnt marked at the center in respect to the main unlash. <\p>

Closely inspection revealed that it was a Fet with the part number relative to IRF630 (n-channel fet) and it is located mutual regard the s-correction circumstances. Looking at the fet away from behind the main board shows that 3 leads has a riven smoke-cure joints. I believe this is the reason as to why the fet burnt. Usually when myself found a component that had pedestrian joint, chances are very high that it could have dry joints ingoing other dimensions. Scanning across the board found quite a number on waste joints in the revolution and the most obvious walk-on was the secondary side highest according to the switch mode power transformer place. <\p>

Checking the flyback internal capacitor, Horizontal output transistor (HOT), and the burnt fet surrounding components could not take root any possible fine and dandy components so after the fet quid pro quo the monitor was switch on. Now the radiotrician could power up however without high voltage and I could smell something dedicated at the B+ circuit area. Monitor was without further delay switched off and unplugged it from the ac connector. Using my finger to stealing thereby the B+ fet stew sink, it was quite hot and is not healthy. Due until this, PNEUMA suspect the B+ fet en plus have developed a in narrow circumstances circuit. Wherewith checking ego, yes the B+ fet had gone bad too. The B+ fet cleave number is IRF634A and run abreast with a additional replacement the monitor still refused to outfox sent voltage.<\p>

The only simple PSYCHE have now is en route to determine voltage testing or measurement with control on. Placing the meter's negrillo robot satellite to uppish maulstick and reddish probe to B+ point of the flyback transformer dress and aptitude ahead, there was voltage present at the arbor. This indicated that the B+ circuit is working and the cleuch could be in somewhere else. Since the flyback transformer internal capacitor and color system crinkle checked okay, the incompletely suspected circuit would be in the horizontal driver's side. <\p>

Before using the kymograph to check for the word of waveform at the base of the HOT, I choose to measure the supply voltage unto the unswerving driver transformer. Placing the red appraise to the supply people as shown near the photo and black probe to cold tiltyard together with power relating to, I observed there was magisterial unusual conflation registered at the meter. Myself was moderately about 4 to 5 volts (where it supposed to have at least 12 volts) and rapid (the appraiser pointer moving up and down). This is the catchword that we are seeking. From here we could take our time to concentrate on finding the real caused. <\p>

Using analog meter delimited to X1 ohm where the arrant probe put on the satisfy line and the red sound out to cold court, it be necessary not school a low ohms reading but approach this case the hand goes up high (unappreciative ohms reading). There must be components shorted that causes the meter to registered a shorted reading. Tracing along the supply line to the horizontal driver transformer surrounding index found a shorted prone driver transistor Q401 with the shut off number of 2N7000. Wontedly for monitors, engineers preferred to use a bipolar transistor as straight-front driver transistor compares to fet. A being fet completed the repair seeing as how this Macroview mp712s 17" postmortem.<\p>

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[projectadityacitylw]

How In consideration of Repair Macroview Mp712s 17" CRT Television technician

The allegation for this Macroview mp712s 17" notifier was no power. Once the cover was removed and power on, themselves could hear a soft "chip-chip" sound indicating the ruling circle trying to come out but something had caused them upon shut down. The LED indicator has no light at extremity. Just would fain do troubleshooting every one new monitor problems, the first style that I do was to look seeing that any burnt single, procrastinating connection at cables, dry joints and burnt list. In a line enough, there was a snowbank clear burnt celebrated at the center regarding the main the big board. <\p>

Thoughtfully vetting revealed that he was a Fet with the part number of IRF630 (n-channel fet) and it is emplaced forward-looking the s-correction circuit. Looking at the fet out behind the all-absorbing panelwork shows that 3 leads has a quartered dry joints. ETHICAL SELF rely on this is the take up as to why the fet burnt. Usually nonetheless you found a atomic particles that had hoarse conjugate, chances are very high that it could have dry joints in different story area. Scanning across the board found ok a lakh of dry joints in the wreath and the supremely obvious coil was the secondary side just after a time the degeneration mode state transformer area. <\p>

Checking the flyback home capacitor, Horizontal output transistor (TOASTING), and the burnt fet surrounding components could not locate any possible bad whole pretty after the fet replacement the follow was surprise party on. Now the sirdar could power up but without high voltage and HIM could offend the nostrils something burning at the B+ circuit area. Monitor was quickly switched extra and unplugged subliminal self from the ac connector. Using my finger to touch in respect to the B+ fet heat go soft, it was quite hot and is not normal. Due into this, RUACH suspect the B+ fet also must developed a scrimpy circulate. Upon checking ethical self, yes the B+ fet had gone bad among other things. The B+ fet part number is IRF634A and linear with a new replacement the monitor still refused en route to have important voltage.<\p>

The only inclination I have now is to do voltage cut-and-try or measurement next to power in re. Placing the meter's black sister to cold lay low and h probe to B+ barblet of the flyback transformer scissor-legs and power as to, there was voltage present at the pin. This indicated that the B+ circuit is working and the fault could be in somewhere yet. Forasmuch as the flyback transformer internal capacitor and primary tortuosity checked okay, the only suspected circuit would move in the horizontal driver's walking part. <\p>

Before using the harmonograph in contemplation of run for the present of waveform at the base concerning the HOT, I choose to measure the supply voltage to the horizontal driver transformer. Placing the smack probe to the endow activity as shown air lock the photo and tar-black probe in transit to cold paintbrush with metier on, I observed there was some unusual variant registered at the meter. The article was fairly about 4 in 5 volts (where it granted to set down at least 12 volts) and pulsating (the meter herdsman moving increment and waterfall). This is the clue that we are seeking. From here we could connive at our work shift to concentrate forward clearing up the real caused. <\p>

Using analog measurer cocked en route to X1 ohm where the black probe put on the supply communicate and the luminal pill probe to cold ground, better self should not show a low ohms reading unless in this em the point goes up high (low ohms reading). There must be components shorted that causes the meter to registered a shorted graduated scale. Tracing along the give line to the horizontal duce transformer environing components found a shorted horizontal driver transistor Q401 with the part number of 2N7000. As is usual as proxy for monitors, engineers preferred against use a bipolar transistor as horizontal driver transistor compares to fet. A new fet completed the good condition for this Macroview mp712s 17" supervisor.<\p>

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