Technically minded Weblog

Got another PC for repair.
This one stopped working after a sudden power failure.
Specs are:
CPU: AMD Sempron (unknown, was too lazy to take the heatsink off), Socket 754
MB: ASRock KBNF4G-SATA2 (Or K8BNF4) (nForce, with built in GF6100 GPU)
RAM: AM1 512MB DDR
HDD: Excelstor 80GB IDE
PSU: Codegen 300W

Totally stone dead, no beeps (even without RAM). Fans run, but nothing more.
Tried clearing CMOS, swapping PSUs, tried running with only RAM & CPU (& built in VGA) but the system remained totally dead.
Probably the crappy Codegen PSU did not like the sudden power failure or maybe a power surge went through it and killed something on the board. The PSU still works through, voltages seem to be in spec.

Another system bites the dust. Good for parts only.

Ordered myself a USB 3.0 expansion card and a 500GB 2.5″ USB 3.0 external hard disk.
From the benchmarks, USB 3.0 looks at least 3x faster when it comes to external hard disks (70-80 MB/s vs 20-30 MB/s for a 2.5″ drive).

USB 3.0 hasn’t hit the mainstream yet.
But there are already USB 3.0 flash drives, external HDDs and external HDD boxes available. USB 3.0 will definitely replace USB 2.0, probably just like 2.0 replaced 1.0.

Will update the blog when my new hardware arrives.

At last I’ve found some time to update my blog.

A week ago, I got two laptops for repair.
Laptop 1 was a custom build based on Asus board. It had a Core Duo CPU with ATI video (pre HD Radeon) This one was stone dead. Even running with only RAM and CPU did not work.
The strange thing is that the CPU was getting hot as if the system was working but there was no disk activity and the screen was blank.
Either way, I did not bother trying to repair this system. My suspicions are that either the processor or the mainboard is toast and the system is not worth fixing.

Laptop 2 was a Dell Latitude D620.
This one was semi-working but had video problems. The system did work and boot (there was disk activity) but the screen was blank.
I’ve managed to get the video to work (sort of) by using an external monitor but the video was corrupted (Windows XP boot screen was all messed up. Even the BIOS setup screen was slightly corrupted).
Then I’ve tried disconnecting the external monitor and the internal screen suddenly started working but the video was unstable (the screen was turning itself on and off like crazy)
and had artifacts. After some time the video stopped working at all (both external and internal monitors).

It seems this is a common problem with some laptops. The graphics chip (mostly nVidia chips) BGA (ball grid array) soldering cracks and stops making contact.
The system still works (sort of) but the video is dead or unstable.
This problem can be fixed by replacing the graphics chip but it is usually not worth it because this requires special tools for working with BGA chips and, of course, a new graphics chip which is expensive.

The owner has asked me to backup all data on the hard disk. Fortunately, the HDD was SATA so I have connected it to one of my desktop systems and backed up all data to DVDs.
After the backup was complete, I’ve returned the system and backup DVDs to the system owner.

This ends today’s story.

Yesterday, I was trying to fix a P4 era IBM desktop.
This one has a P4 3Ghz HT CPU, 768MB RAM (512MB + 256MB upgrade), some AGP video card, 2 hard disks (one SATA and one IDE) and 2 optical drives. The motherboard is some IBM rebranded Intel (Foxconn) board.
The case and PSU are proprietary (but PSU uses a standard ATX plug). PSU is Hipro 230W (?) with a dead fan.

Now the problem:
The title says it all. The system is stone dead. It does nothing except turning on and off. Tried clearing CMOS, running with a different PSU, swapping video cards, running on integrated VGA, running with only one RAM module, running without any RAM at all (no beeps).
This system does not show any signs of life. No beeps and nothing on display. The hardware shutdown (hold power button for a few seconds) works though. I suspect that the BIOS might be corrupt (and there’s no way to restore it because the BIOS chip is soldered in). Too bad I don’t have a POST card…

None of my s478 boards fit in this proprietary IBM case so I cannot just rebuild the PC using one of my s478 boards.
So this system is probably good for parts only (CPU, RAM, VGA, HDDs, etc.) unless the system owner would find a compatible board that would fit.

The title says it all. Fixing yet another PC.
This time, it’s a P3 era PC with a 1 Ghz Celeron Coppermine cD0
But the PC is in a really bad condition. I’ve had to do a nearly complete rebuild to return this system to a working state.
1. Motherboard (branded Manli) had some bad capacitors near CPU socket (8 identical caps, one leaking)
2. The system had a really crappy power supply (very light and specs overrated)
3. One of 2 PCI133 RAM modules was bad
4. (on the software side) Windows install was corrupted (not even safe mode worked)

Here’s what I did:
1. Replaced the motherboard with Intel D815EEA (nearly a complete system rebuild)
2. Replaced the bad Samsung 256MB RAM module with 256MB Micron (Nanya OEM)
3. Replaced the power supply with a 350W Codegen I had laying around (not the best PSU, but much better than the one it replaced)
4. Added another hard drive (a ye olde Samsung 10GB)
5. Reinstalled XP

Now, some more details.
I could not install XP on this system. The setup always stopped with “Could not copy file x” or “File x was not copied correcly”. Attempting to retry the file copy had no effect or resulted in some random BSOD. Sometimes, the setup would just crash with a BSOD during file copy.
I’ve tried using my UBCD to scan the hard disk, but WinPE always crashed with some BSOD soon after booting to desktop.
I’ve spent a few hours trying to figure out what was wrong. It turned out that one of the RAM modules was bad (the system had one Samsung 256MB module and one 128MB RAM module branded Exram, 256MB Samsung was bad).
Replacing it with a 256MB Micron solved the problem.

Now I need to:
1. Install all the needed software (Office suite, media players, video codecs, etc.)
2. Restore the owner’s old data from a HDD backup.

I hope I will have no more problems with this system.