First post, by adalbert
I finally managed to fix my second mobile Radeon 9000 video cards for Dell Inspiron 8200 (P4-M) laptop. I replaced four BGA memory chips (half of them I replaced 6 months ago...). I already fixed another Radeon 9000 card 5 years ago, installed in Inspiron 8100 (P3-Tualatin), and it still works, so I hope both of them will continue to live for a long time.
I recorded a video of the process which maybe could provide some educational value, it includes all steps:
https://www.youtube.com/watch?v=T6mXM1tA7pA
Tools I used: not quite professional setup, I used an 220W 24V aluminum preheater made of 3D printer heated bed, and one of the cheaper hot air stations. The preheater heats up to 125 degress Celsius (i installed a bimetallic switch... will need to make a proper temperature control), which makes the top surface of the card reach around 80 degrees Celsius. It seems to be good enough for older harware which uses leaded solder, but I certainly wouldn't use that setup with modern lead-free hardware.
I used some flux and desoldering wick to clean up solder pads before soldering new chips. I damaged some solder mask and had to repair it with UV curable solder mask.
I replaced four original Infineon HYB25D128323C-3.6 128 Mbit DDR SGRAM chips with two Samsung K4D263238G GC33 128Mbit GDDR SDRAM chips with pre-applied solder balls. Earlier I tried reballing, but it didn't help (though it was enough for my older video card).
The video card seems to work fine after few days of testing, and the other one still works after 5 years, so maybe this kind equipment is OK for repairing old video cards (though 5 years ago I used bunch of candles as a preheater 😁).
I think that such simple aluminum preheater could also be quite helpful in generic SMD repairs - its temperature is not dangerously hot, should not melt plastics, but certainly helps in warming up things, and could make replacing regular SMD component easier. Next I will try replacing faulty SMD memory chips in GF4 card.
Repair/electronic stuff videos: https://www.youtube.com/c/adalbertfix
ISA Wi-fi + USB in T3200SXC: https://www.youtube.com/watch?v=WX30t3lYezs
GUI programming for Windows 3.11 (the easy way): https://www.youtube.com/watch?v=d6L272OApVg