Don't Miss

Musical Keyboard Repaired

By Jestine Yong on January 2, 2024

A guy from a school nearby brought this musical key board for repair. He said the keyboard is not coming on and they want it fixed.

I powered on the device using the power supply that came with it and sure enough it was not working at all. It was not showing any kind of life so it was time to open it and see what is wrong.

From the look of this device, it was beat up and not in good shape but the guy insisted on getting it fixed because it has Arabic scale music and not easy to find one like that so I started taking off a lot of screws on the back of it to expose the internal board.

This is the power supply that came with the device. When I tested it with my meter, it was only giving 15 DC volts although it should be giving variable voltages so our first problem is the power supply itself.

Before proceeding with the repair, I tried to power on the device using my external power supply but the problem remained, it was not powering on so my focus was set on the female power port on the board.

First thing that I saw was the cold solder joints on this board especially the main power port. The power port was connected to the board with wires and it was loose. I added a fresh solder to the pins of that board and as seen in the photo it was solid. I also re soldered some of the cold soldering joints on board and hoped for the best.

I powered on the device through an external power supply and the device came on using 6 volts and 1 amp which was specified by printing on the back of the device.

I purchased a new power supply from the electrical supply store near but and as agreed with the customer it will be included in the cost of the repair.

I called the school and told them of the outcome so they send another guy to pick up the device and with him papers were brought for me to sign which have to do with payment and money received. I signed the papers, they took the device and he left my shop.

Mission Accomplished.

This article was prepared for you by Waleed Rishmawi, one of our ‘Master Authors’ and currently working in the Bethlehem area of Palestine repairing electrical and electronic equipment.

P.S- Do you know of any your friends who would benefit from this content that you are reading now? If so, forward this website to your friends or you can invite your friends to subscribe to my newsletter for free in this Link.

Note: You can check his previous article on A Dental Drilling Device Powers On But The Drill Not Rotating Repaired

Likes

(39)Dislikes

(0)

13 Comments

Albert van Bemmelen

January 2, 2024 at 10:41 pm

I suppose that you couldn't repair the mentioned Solma SL-1000DB AC-DC adapter anymore, probably because the transformer was defect only giving 15V output.

Likes(3)Dislikes(0)

Reply
- Waleed Rishmawi
  
  January 3, 2024 at 8:36 pm
  
  Albert: the adaptor was damaged beyond repair otherwise I would have repaired it. have a blessed day
  
  Likes(1)Dislikes(0)
  
  Reply
B. Scott

January 2, 2024 at 10:46 pm

Good job...however when I do these kinds of repairs, they have to pay for the repair when the equipment is picked up....I used to do it your way at first but would take a few months to get paid so I had to do it differently....same as getting your car repaired in a garage....you pay when it is picked up.....that way you can be guaranteed to get paid when the job is completed....cheers.....

Likes(3)Dislikes(0)

Reply
- Waleed Rishmawi
  
  January 3, 2024 at 8:39 pm
  
  B.Scott: thanks man. how would you do the payment differently? usually I get paid once the device is repaired and that is about two or three days tops. I let them sign a paper to pick up as soon as possible and after two weeks time if the device was not picked up by the customer I have the right to do whatever feel like with the device. so far it is working fine. have a blessed day
  
  Likes(1)Dislikes(0)
  
  Reply
Parasuraman S

January 3, 2024 at 12:17 am

Good repair job with professional way of fixing plus money receipt. It is not yet clear why you could not repair the adapter.

Likes(0)Dislikes(0)

Reply
- Waleed Rishmawi
  
  January 3, 2024 at 8:42 pm
  
  Parasuraman: thanks man. the adapter was damaged beyond any repair and if i want to repair it, it would cost a lot for the customer so the best was to get a new one which did not cost that much. it is about working smart not working hard.have a blessed day.
  
  Likes(2)Dislikes(0)
  
  Reply
  - Parasuraman S
    
    January 4, 2024 at 3:31 pm
    
    Well, OK, dear!
    
    Likes(0)Dislikes(0)
    
    Reply
Robert R Spoon

January 3, 2024 at 12:37 am

Waleed, I have done hundreds of repair jobs like this for the schools and colleges in my area and have 100% success rate on getting paid for the job even though it takes a couple of weeks in most cases. On COD customers I ask for a deposit when the equipment is dropped off so I know they have some investment already. Your diagnosis and repair were spot on and I know your customer was thrilled to have it back working again. Great Job!

Likes(1)Dislikes(0)

Reply
- Waleed Rishmawi
  
  January 3, 2024 at 8:46 pm
  
  Robert: the deposit pay does not work well in my cournty. I always inform the customer about estimate fees in case the machine was not fixed or we did not agree on the repair cost. I ask the customer to sign a paper to pay as soon he pick up the devie and if the device was left in my shop for more than two weeks I have the right do whatever I like with the devie. so far I did not have any serious issue with my customers. have a blessed
  
  Likes(1)Dislikes(0)
  
  Reply
Babu M S

January 4, 2024 at 1:03 am

Good fix and given life for the keyboard.I am facing one problem in audio set LG make. The power supply board smps outputs were 21 volts and 22 volts. both the outputs fluctuvates from 19 volts to 21 volts.Main filter capacitor voltage shows 324 volts.I have replaced optocoupler, filter capacitor, and power ic 1790A(smd type). Checked all the resistance value,found ok.It is very small power supply board, brand new.please help me to solve the problem.

Likes(0)Dislikes(0)

Reply
- Parasuraman S
  
  January 4, 2024 at 3:33 pm
  
  Is it oscillalting even when the load is given? Then, the filters in the seccondary might have to be replaced too. Check all components from run DC circuit to output, such as resistance value, capacitance value etc. Check for any leaky diode or transistor too.
  
  Likes(0)Dislikes(0)
  
  Reply
- Waleed Rishmawi
  
  January 5, 2024 at 3:09 pm
  
  Babu: is it fluctuating with a load or without? since you replaced all that and still have issues, I would checked the smd components and the secondary section of the power supply. have a blessed day
  
  Likes(0)Dislikes(0)
  
  Reply
Yogesh Panhchal

January 5, 2024 at 8:13 pm

Good job! Waleed,
Most of commercial customers have this procedure of payment receipt.it is always safe to take part advance payment.because some time peoples change their mind because they have not paid us anything & material you purchased becomes waste.

Likes(0)Dislikes(0)

Reply