yes you are right. before desoldering, we must re-touch solder by applying some fresh solder. it is better for thermal conductivity and it prevents the pcb from overheating during desoldering process. more over it removes the dust rust and oxides from the old solder, so it doesn't allow the dust to stuck in old and contaminated old solder inside the desoldering tool nozzle . otherwise the old solders chokes the desoldering tool's nozzle
I have experienced that old soldering takes too much time to melt and damage the surrounding area. and when applied new soldering first, it took less time.
Thank you, Mr. Hasseb, for sharing that informative teaching video. Once again, you're aways putting safety in your videos first, and I really appreciate it. It can be so easy to forget to tape up those wiring from touching while you're power up a circuit board! Very important details technicians should never overlook.
Very useful teachings. I always enjoy watching your contents here sir. A lot of us technicians will benefit from what you are sharing. We often times encounter problems in Inverter Air conditioners. Hope to have more contents about Inverter AC issues and errors. Much love from Philippines.
i use WELLER WR3M rework station and most of time is use solder from BOW electronics USA, CASTER, alpha brands i shop online from rs-online, amazon, farnell
If I heard you wrong on certain video you said if there is small voltage at the output and fluctuating then I have to check the secondary ( output side ), if there is full voltage but fluctuating then I have to check feedback section. So you checked snubber circuit because pwm IC was heating?
1. if we have few millivolts with fluctuations at output side, and high fluctuations on vcc capacitors & bulk capacitor ---- possibility secondary side have short circuit 2. output side, no voltage. vcc capacitor & bulk capacitor high fluctuations --- possibility output side open 3. output side high voltage + fluctuation, vcc capacitor & bulk capacitor fluctuation --- possibility feedback network 4. low output voltage (approx 1 volt and above) -- possibility RCD snubber, dry joints in high current components (transformer, mosfet, current sense resistance, rectifiers etc) when rcd snubber diode is short circuit, it creates a parallel path with transformer winding, thus it doesn't allow to built required magnetic field in primary, and the circuit draws more current, because in this situation there is just one capacitor (part of snubber circuit) that is parallel to the primary winding because capacitor provides very low XC at high frequency, while at the same time the transformer provides more XL
it is my pleasure these are my own troubleshooting tricks sometimes there some other things are interconnected with some fault condition but mainly these symptoms lead us to pinpoint location
1N4007 have nominal capacitance 15pF upto 1MHz, this diode have a junction capacitance of 1PF. so it can be used at 100KHz. and it is most commonly used in smps snubbers. FR107 is also sued in same place.
is there a universal diagram for the switching power supply for TV and receiver and others just to understand and troubleshoot our power supply thank you friend
Assalamualaikum bhaiya.... Bhaiya I'm very confused in positive , negative and ground what is defference amoung it.....I've been failed to find answer of whole RU-vid..... Bhaiya if you read this comment plz plz Clear all this doubt..... Like what is defference..... +12, -12, and what is ground.....??? Q¹....What potential deference will be between +12 and ground , -12 and ground, +12 and -12......? Plz plz plz plz make a long videos with deep detail. ....🙏🙏🙏🙏🙏 ... . . . .. God bless u
Djazak Allah khayran , for the title the correct word is "ne s'allume plus" , for the atx power supply if the stand by voltage is present but the power supply doesn't start up I checked the only Ic in the board vcc and vref are present can we say that the Ic is faulty
yes brother if the board model number is same, same service manual can be used for that one, either it is samsung, philips or any other brand. as these boards are universal. different assemblers purchase boards from different companies and they produce their product
Checking shorted semiconductors should be done first. And 1N400x diode is slow rectifier, around switching IC you should use fast diodes , like BA159 or 1UF4007 (probably used original )
