I can diagnose most any pc problems down to the component level.... thats really easy.

And without a SMD or BGA rework station I likely cannot fix a ton of issues since northbridge problems are fairly common.

Things that are likely worth solving:

Bad capacitors. Decently common and the parts only cost a few cents.
Most of the ICs on board... 4-20 pin jobbies such as the power ic do fail and are swappable for less than a buck or so
Blown fuses. Easy to diagnose easy to replace. This is a definite.
Any and all damaged jacks. Power and audio being the most commonly broken.
Resistors. easy to find easy to replace. cost is in pennies
Transistors and diodes can be more problematic to diagnose and fix but they too are cheap and swappable with just a soldering iron.
Obviously i can swap cpus so I should be able to diagnose that as well.

I can't fix:
Northbridge or the vga chip without a BGA rework station so that is out of the question even if i have to be able to diagnose it


I found an example of the dude that does pretty much what is expected of me:


"Machine: HP G6000(same mainboard as V6000)
Problem: not power up

The machine has been water damaged. It does not have system standby power, which are 3V and 5V.

Check Max8724(the battery charging chip) first, because to make system has standby power this chip must work correctly. This is a 28 pin chip, we only need to test 1, 2, 4, 8, 10, 11 pin. They are VIN(main power for chip), LDO(provide 3.3V for chip itself in order to set REF voltage, also provide signal to drive 2 MOS to charge battery), REF(set reference voltage of the chip), SHDN#(enable/disable chip, a switch), ACIN(indicate the power supply has plugged in), ACOK#(power adaptor ok with mainboard).

Everything ok except 10 pin, ACIN is 0V. This is incorrect, mainboard doesn’t detect there is an adaptor! Trace it backward and find it is very simple – mainboard use 2 resistors to pull the input voltage(19V, directly from dc socket) down to about 4V, so test the first resistor and find it opened. Change it and 3V/5V power come up and mainboard be able to switch on.

Then the trouble start when I try to charge the battery. The charging current never go beyond 0.15A and after 10 seconds the charging light start to flashing. Also can’t switch on from battery. First, change Max8724, still same problem. Next check all the resistors around max8724 and change it if it has any sign of watering, still no good. Then change KB3926(EC/KBC, chip monitors the statue of battery), still same. This is the fault that I never dealt with before.

Decide to check MBDATA and MBCLCK, 2 signals that send battery information from battery to KB3926 before I give up. I find the MBDATA is short!

Finally, find there are 2 pins stick together on CN10(the connector of multimedia switch board). Fix it and it start to charging battery. Switch on with power adaptor, ok. Remove the power adaptor once switch on, battery keep the mainboard running, ok. But still can’t switch on from battery once remove the power adaptor. Think, think, do I miss something here or there? Oh, the CMOS battery not installed, put the CMOS battery back and everything work perfectly. The battery part of troubleshooting takes me about 3 hours.

Remember, system may not run if you don’t have CMOS battery or CMOS battery is low for some AMD cpu mainboard.

I wrote this just help people who interest in repair mainboard have idea how to check the problems on mainboard."