An LCD computer monitor repair. Model Harma 983A

A guy next door who is in the business of selling computers and computer screens brought me an LCD computer screen. The problem was ticking noise in the speakers and there was no picture.
I connected it to my laptop at the shop and there was ticking noise coming out of the speakers and the LCD panel was dark.
I have seen this kind of problem before and it was an easy fix. The moment I took the cover off, I could see a bad bulged capacitor in the secondary area of the power supply. It was a 1000uf/25 volt. Usually when there is a bad capacitor in that area, I check the others to make sure all of these capacitors are in good working conditions. All of them checked ok.
I replaced the bad capacitor and tuned the machine on. I still could hear the ticking noise coming out of the speakers. I was one step ahead when I replaced that bad capacitors but seems like there are more bad components in that area that needed my attention. I turned the machine on again and started doing voltage testing. There was a steady 300 volts at the main capacitor but when I tested the voltages at the secondary diodes, there were voltages there but not steady which gave me the indication that something is wrong in the power supply.
I asked myself, why the bulged capacitors why there is only one that has this problem, so I traced it back from that capacitor and near by it there was an SMD component that was kind of melted component. Near that SMD component was writings near it. This component was supposed to be a Zenner diode. Under a large magnification, I could read on that component 7.5 A. after a long search on the net, I came to a conclusion that this is a zenner diode 7.5 volts. I replaced it with another zenner diode but not SMD component. I soldered it in its place and turned the machine on. The ticking noise was gone and I could see the NO SIGNAL sign coming on the LCD panel.
I connected it to my laptop and I could see a picture coming on and the sound was great. I let it run for about an hour with the cover off to make sure that nothing is over heated especially that zenner diode that I soldered on that board. It was working fine. The voltages were steady and that zenner diode was ok.
I called the guy, actually yelled his name just outside my workshop door and he came running. He was happy that the machine is working fine. I was happy to see it come to life. It was great and the pay was even better.

Toper by the Italwin Group DC Welder repair. Model ZXP-170

The problem was it does not weld; At least that what the customer told me. Later on I realized, it was a different problem and was very easy to fix.
I took the cover off and turned it on and nothing happens, I was suppose to hear the cooling fan spinning but I did not, instead, I could smell something burning and the smoke was coming out of the cooling fan. I turned it off and looked closer at the fan. I tried to spin it by hand but it did not spin. It was a bad burnt fan.
A bad not spinning fan does not mean the welder is not working. The machine is working fine but the fan is very important in that machine. If the fan was not working and the machine is working, eventually, after a while the machine will go into shut down causing over heating caused by a fan not spinning and cooling off the machine.
It was a 220 volts fan. The motor was completely burnt and the plastic around the motor was melting and it smelled bad. The only problem I was facing in this machine is the ordering of a new fan. It takes about a week or so to get it and the customer was in a hurry to get it fixed. I called so many stores but without any luck. I have to place an order and wait for it.
I remember a while ago, someone brought me a DC welder to be fixed but it was too expensive and the customer did not come by the shop to pick it up. I went to the storage room and found the machine. There were two working fans in that machine. I called the customer and told him if he is interested to sell the DC welder for a cheap price and he said he not need it and offered me to take it for free. That was nice music to my ears; I took the old machine to the shop, took one of the working fans out and installed it in the machine I was working on and the fan worked very nicely.
I took the machine to my brother’s shop next door, connected all the wires needed for the welding process and turned it on. The fan started to spin and my brother tried the machine. It was working fine.
Called the customer to come and pick up his machine. He was so happy that the machine was working fine and was fixed in a very short time. He was happy, I was happy. Case closed.