The three of them left the library one after another. When locking the door, Du Qiu and Su Wenxiu's brother met each other and knew that his name was Su Wenhai, so they almost said: "There is a road in the mountains of books, Wenhai is endless. Brother Hai is a good name, which is much better than my dry Qiu word."

"What's the use of good sound? I have been re-educated in the third year of junior high school but haven't been admitted to high school. In fact, I should have changed my name to Wenzha." Su Wenhai is very cheerful and not pretentious. After making fun of himself, he smiled and said, "If you like it, I'll sell you the name, just one dollar."

"Brother Hai's kindness is recognized. I lack fire in my five elements. I need fire in my name, not water."

Su Wenhai was obsessed with Du Qiu's ThinkPad. After Su Wenxiu locked the door, he walked towards the elevator and said, "Brother, if your laptop cannot be repaired, can you sell it to me cheaply?"

"Is Brother Hai engaged in the computer industry?"

"With my half-baked junior high school education, how can I do computers? I repair home appliances. The price of computers is now dropping quickly. In the future, it will definitely be available in every household like a TV, so I want to study it first."

Is this guy very business-conscious?

The moment he walked out of the library gate, a cold wind blew, and his body became cold. Du Qiu couldn't help but tremble. He rubbed his exposed arms, looked around the familiar and unfamiliar campus in the night, then took a deep breath and asked tentatively: "Brother Hai, can I stay in your place for one night?"

"What are you doing? You won't go back to the dormitory?"

"It's past 12 o'clock now, and the dormitory building has already locked the door. I had a conflict with the guardian a few days ago, and I couldn't help but beg him to open the door." Du Qiu forced his acting skills, shrank his neck, and said with an awkward smile: "I have never suffered any grievances since I was a child. I am better off. I usually pretend to be a boss and pretend to be a boss. I am so embarrassed tonight, so I can't let those classmates know anything."

In 1995, China was still in the early stage of economic growth. The income and quality of life of residents were relatively low, and it was far from comparable to 2016. Although Du Qiu's T-shirts and shorts were not high-end products, they were exquisitely used, cut appropriately, and looked very fashionable. In addition, the valuable laptop in the backpack naturally made the Su brothers and sisters think that he was a rich child with a superior family. It was not surprising that rich people love face. Therefore, after hearing this, Su Wenhai and Su Wenxiu looked at each other and saw that she did not object, they said: "Our family is relatively small and there is no extra bed. If you don't dislike it, squeeze with me tonight."

"Thank you, Brother Hai, and thank you Teacher Su."

"What kind of teacher Su is just a yellow-haired girl. She only celebrated her 20th birthday in July this year. She must be not as old as you. You can just call her name."

"Brother! What are you talking nonsense..."

The Su brother and sister live in the school's dormitory building. It is not large in size, one bedroom, one living room, no kitchen, but an independent bathroom, about 60 square meters. Both the building itself and the decoration style are a bit old and look very old. There is a desk modified workbench in the living room, which is filled with messy parts, and there are different types of old appliances such as TVs, washing machines, and video recorders, making the whole house look messy and crowded.

Su Wenxiu didn't speak much, but she was very considerate. As soon as she entered the house, she poured a cup of hot water for Du Qiu, then found a set of thermal underwear and said, "This is what my brother just bought a few days ago. I haven't worn it yet. He is not as tall as you, so he may not fit well. You can make do with it first."

"Thank you, Teacher Su, thank you so much."

It really doesn't fit well. Du Qiu is tall, with bare feet over 1.8 meters, Su Wenhai is only in his early 1.7 meters, and his clothes are two sizes apart. He is tight on his body. However, in this state, some people are good to wear and can't ask too much. When he was wearing clothes, Su Wenxiu avoided suspicion and went back to the inner room to rest. Su Wenhai pulled the sofa that was half-new in the living room into a bed, then carried a quilt out and said, "If you are sleepy, go to bed first. I still have some work to do."

"What are Brother Hai going to repair?"

"VCD video player." Su Wenhai pointed to the black box with eight pieces on the workbench and said, "This is the first time I repair this thing. It's different from a video recorder. I haven't done it all night."

VCD was released in 1993, and became popular all over the country in 1996. It was eliminated after 2000. Du Qiu was born in 1990. His childhood happened to catch up with the years when the VCD machine developed rapidly. He used it to watch many movies and cartoons, leaving behind beautiful memories. He became interested and asked, "What's wrong with this VCD?"

"Don't read the disc after loading it."

Du Qiu was extremely excited at this time, and his brain cells were boiling like boiling hot water, and he was completely sleepy. So he stood beside the workbench and watched. Seeing Su Wenhai poking the circuit board and pounding it around, he seemed to have no clue and asked, "Do you have no repair instructions?"

"This is a second-hand product I bought. There is nothing except the machine. Not to mention the maintenance manual, there is not even the instruction manual." Su Wenhai said while using a multimeter to measure the level: "VCD machines are high-tech products that have just been released. They are rare on the market. Whether it is a school library or a Xinhua Bookstore outside, they cannot find relevant maintenance materials, so they can only explore slowly."

VCD is a high-tech product...

Du Qiu has never repaired VCD, but has tinkered with DVDs. The main difference between VCD and DVD is the different decoding capabilities and the circuit structure is similar. After observing for a while, he pointed out: "Brother Hai, if you don't read the disc, you either have a problem with the laser head or the servo control circuit in the movement, you don't need to check the decoder."

"Do you understand this?" Su Wenhai was a little surprised when he heard this. He looked up at him and said, "I have checked the laser head. It's very normal. Which servo control circuit are you talking about?"

Du Qiu pointed at a position and said, "You measure the RF pin level of this microcontroller... If it is high, it means that the RF output is not normal... You test the RF amplifier again to see if there is a signal output... There is a signal? That should be a problem with the focus detection circuit..."

One said and the other did. Soon, a coupling capacitor was found on the circuit board that was damaged due to leakage. After changing it, it was connected to the TV and tried it with a karaoke disc. Sure enough, Su Wenhai was very excited. Regardless of the late night, he held a screwdriver as a microphone and sang a song with Andy Lau on the TV: "I dare not think about it, I shouldn't, thank you for your love, I have to exist..."

After singing for a few words, Su Wenxiu walked out of the room with a hand-knitted old sweater and a pair of blue sweatpants, glared at Su Wenhai, and said, "Brother, you won't look at what time, and you won't sleep yet!"

Su Wenhai was very pampered by her girl, so she followed her advice and immediately stepped forward to turn off the TV, and said with a smirk: "Go to go to bed right away."

Su Wenxiu snorted softly, put her clothes on the sofa bed, and said to Du Qiu: "My brother is a night owl. He slept very late at night. You can wear these two clothes first, be careful of a cold."

What a lucky...

I just traveled through time and met such a warm, caring and careful girl...

After Su Wenhai waited for his sister to go back to the house, he moved the VCD machine back to the workbench and asked enthusiastically: "Brother, how did you know that it was broken there?"

Du Qiu thought that he couldn't sleep anyway, so he simply did something small to repay the friend who took him to spend the night. So he put on his clothes and opened his backpack, took out a pen and notepad from it, and drew a schematic sketch on the circuit board, explaining: "The DVD player is generally composed of four parts, namely disc drive, movement circuit, system control and decoder. The disc drive part is relatively simple. Brother Hai understood it at a glance, so I won't say much; the decoder is packaged, and if it is broken, it can only be replaced, and cannot be repaired; as for the system control part, it is mainly a microcontroller..."

"I often hear people talk about microcontrollers, but I can't figure out what exactly is it?"

"The full name of a single chip microcomputer, also known as a microcontroller, is a microcomputer that integrates a central processor, memory, timer, counter and various input and output interfaces on a circuit chip." Du Qiu explained the basic concept and saw Su Wenhai being confused and ignorant of understanding, and then said: "Understanding a single chip microcomputer requires a certain amount of computer knowledge. Let's talk about it later. Now let's talk about the movement circuit first. Most circuit failures of the VCD machine come from here."

"Okay, listen to you."

"The movement circuit cannot be produced in China, so it can only be purchased from foreign companies such as Sony or Philips. It contains three sub-functions, one is photoelectric signal processing, one is digital signal processing, and the other is servo control circuit..."

After Du Qiu graduated from undergraduate studies, he went out to explore for two years. He thought he was too tired from work, so he ran back to school to study for a master's degree. He was a very high level than that of ordinary graduate students. Therefore, he often replaced his supervisor to teach his juniors who failed the course and re-education. He accumulated a lot of teaching experience. The explanation was easy to understand and clear. Although Su Wenhai had no theoretical foundation, he had rich practical experience. After listening for a while, he felt that he could not understand the clouds and the moon suddenly became clear. The doubts he had been unable to understand before were solved. He couldn't help but be overjoyed and asked like a curious baby. The two of them said one by one, and before they knew it, it was getting brighter in the east, and it was already dawn, and it had already passed one night.

"Brother, you two didn't sleep all night last night?"

Du Qiu looked back and saw Su Wenxiu standing pretty at the door of the bedroom in a pink sweater, as if the buds of early spring were filled with the unique youthful atmosphere of a girl. Although it was not so beautiful, it was also pleasing to the eye and was very touching. He stood up and said hello, and asked, "Teacher Su, what time is it now?"

“It’s almost 7 o’clock.”

"I'm almost time to leave."

"Today is New Year's Day, the whole school is on vacation. Why are you in such a hurry to leave? Have breakfast together?" Su Wenhai held Du Qiu and said to Su Wenxiu: "Little sister, you cook the pot of porridge and buy a few baskets of buns. This guy taught me a lot of things last night. Thank him very well."

Du Qiu had been struggling all night, and was already hungry and now he was penniless. He naturally wouldn't let go of free breakfast. So he stayed with the flow and helped Su Wenhai clean up the circuit boards scattered on the table. In addition to VCD, they also tossed the TV, video recorder, pager and other electrical appliances last night, making the room full of parts and messy.

When Su Wenxiu came back from buying buns, she brought a new toothbrush and a new towel, which made Du Qiu very grateful because he had a slight obsession with cleanliness. He didn't sleep last night, but half of it was really not sleepy, and half was not used to squeezing a bed with strangers.

"Brother Hai, can you lend me a few coins? I'll take the bus and send the computer to repair it. I'll hide at my relative's house for a day, and then go back to the dormitory tomorrow, which will scare those bad friends."

"Brother, you are so interesting. You still don't forget your face after being frozen like this." Su Wenhai laughed and took out a handful of banknotes with varying denominations from his pocket. He generously counted 20 yuan to him and said, "Laptop computers are valuable things. You'd better take a taxi. There are many people on the bus and there are many thieves, so you can easily be stolen."

"Thank you, I will wash this outfit tomorrow and return it to you."
Chapter completed!