DIY Old Laptop to All in One PC

I was busy with some tasks between past weeks. Unluckily, one of my development gear, old laptop was not in a good condition since a few weeks ago. It is a PIII laptop with 1GHz CPU and  loaded with my developments tools. I picked it up from disposal since three years ago. When I picked up this, battery was dead, motherboard was not boot, screen lids were broken.  I checked that mother board power supply capacitors leakage and replaced with new capacitors, fixed the screen lids with some epoxy, glues and heat gun. The old laptop was in service at that time. This laptop was manufactured from  infamous brand  Taiwan manufacturer but it’s performance was surprisingly good and stable. Now, it seem end of life again.

I love recycling and reusing things when there is possible. Is that good for environment and also for my pocket? 😀

So, I started a weekend job to recover this hardware. Here is an original photo of this, screen lids and parts of body are broken. Some keys from keyboard are not respond and motherboard was unstable again.

My Idea is to transform this laptop as All in One PC by flipping installing LCD screen over body and making a base+mounting stand my self.

Laptop-2-AllinOne (1) Laptop-2-AllinOne (2)

Take apart all parts first. Removed battery, keyboard, mouse pad, up-side cover, floppy drive and CD drive.

Laptop-2-AllinOne (3) Laptop-2-AllinOne (4)

Up side cover with speakers, mouse pad.

Laptop-2-AllinOne (6)

Removed LCD screen from body.

Laptop-2-AllinOne (5)

Took off mother board to clean and to check.

Laptop-2-AllinOne (7)

The problem was the same as previous, leakage  capacitors at power supply. Replaced these capacitors and mother board is boot again. This is a common fault symptom of electronics devices especially manufactured about 2000 or cheapo ones.

Laptop-2-AllinOne (8)

Started hand-tools jobs.

Laptop-2-AllinOne (9)

Prepared down side cover holder. Reinforced with two metal flat sheets.

Laptop-2-AllinOne (10)

Finished down side cover with holders. Two L-shape aluminium support ware also installed at the side to fix LCD panel.

Laptop-2-AllinOne (17)

Took off LCD panel. I want to flip LCD panel and re-install it over the motherboard part to form like All in One PC. The LCD  connector cable was a little short to do this. So, the cable was took of and straighten and repacked again.

Laptop-2-AllinOne (11)

Laptop-2-AllinOne (12)

To seat LCD panel over down side cover, I installed L-shape aluminium stands at the back side of LCD cover.

Laptop-2-AllinOne (13)

Prepared the base and stand for mounting.

Laptop-2-AllinOne (14)

Panel mounting was finished.

Laptop-2-AllinOne (15)

The back installation of panel mount.

Laptop-2-AllinOne (16)

The first test assembly of down side cover and mount, base.

Laptop-2-AllinOne (18)

Re-installed motherboard, hard disk. Old battery, keyboard, Floppy and CD drive ware completely removed.

Laptop-2-AllinOne (19)

Speakers were re installed at new place (originally battery place).

Laptop-2-AllinOne (23)

First test assembly was finished. All in One style!!!

Laptop-2-AllinOne (20)


Back side of assembly. L-shape angles are used to attach LCD scree to base. A USB hub is attached and USB WiFi adapter is installed.


I bought a USB keyboard for re-branded PC.

Laptop-2-AllinOne (22)

Finally, the oldie classic PIII All in One PC is alive at my workbench. How a happy weekend hacking.

Laptop-2-AllinOne (25)



Laptop-2-AllinOne (28)

By the way, this is my last post of 2012.



DIY Isolation Transformer

After I bought my test gears such oscilloscopes, I noticed that I should have an isolation transformer in my bench. Then, I forgot again with the other projects. One day, after seeing Dave and Todd videos blog about isolation transformer, I started the construction of DIY isolation transformer. For those interests, here is Dave and Todd explained videos. Thanks both.

Some designed by cascading back to back secondary winding of two transformers (220V||12V<->12V||220V). It also be worked fine but I build my own. One of my buddy’s local transformer manufacturer wound this transformer and give me as present. Thanks buddy again.

It was designed as

  • Rating : 1KVA, 220V
  • The core  cross sectional area : 60mm x 60mm
  • Primary winding & Secondary winding : 300 N, 17SWG

The two winding should be wounded together to avoid turn ratio mismatch.

DIY-Isolation-Transformer (1)

I found old charger chassis and collected some some required staffs such as sockets, fuse etc.

DIY-Isolation-Transformer (2)

Seated transformer at chassis base. Prepared face plate, cover hole with plane PCB, installed input and output fuse houses, lamp. And wiring,


I agree with Todd suggestion. This is the schematic from commercial isolation transformer. The output winding NEUTRAL is CONNECTED to main GROUND!!!


This is the edited diagram as per suggestion. Disconnected secondary winding (NEUTRAL) from main GROUND. Mine has no circuit breaker and surge protection but both input and output fuses.


Final assembly is look like that. A new tool is at my bench.

DIY-Isolation-Transformer (7)

Note :

– DUT (device under test) should be isolated with transformer rather than oscilloscope.

– BUT, Dave scenario-3… if  DUT power supply is grounded to chassis (main ground), the problem is still existed. Disconnect DUT ground ?? or use with floating power supply?! or with battery? 😛

– Test device such as oscilloscope should not be floated (must be grounded) without special reason.

– Most forum and articles talked about isolating oscilloscope not DUT. If someone know the best practice and pros, cons, let me know.

– Differential probe, usb isolator are also good but cannot still effort.

– I need GFCI outlet at my bench.


I recently found a post at Keith’s Electronics Blog. There is also original schematic from manufacturer. It isolates even ground pins of each output. Yes, system ground (Chassis ground) is purposely isolated.

– My thought is that isolating system ground has some pro and cons. Sometime we need to isolate for full safety or purposely. In most case, test equipment should be grounded for safety.

Refrubrishing My Isolation Transformer

and schematic from Keith’s Blog