Recently got me a Compaq Prolinea 4/50 as I liked the low profile look of the computers. Was able to talk the seller down due to obvious battery corrosion... and wow no kidding; the old Ni-Cad battery had eaten away parts of the PS/2 circuit, specifically for the keyboard. Amazingly other than some corrosion on the serial port screws, nothing else was damaged. The computer even booted up to the BIOS detecting an issue with the keyboard system.
I doused the area in 99% isoproyl alcohol to try and neutralize the acid. The PS/2 connectors were pretty corroded themselves and I wanted to clean and see the damage underneath em as well... so they were desoldered and removed. My camera can't get all the detail, but here is the top side: From what I can tell the ground trace has totally been eaten away by the battery acid. The bottom side is thankfully fine. Pretty lucky!
The good news is after probing around I found where the data and clock pins finally end up on the FPGA (is it too early to call this a chipset?) from the mouse port. Looks like the mouse circuit is still intact. On the keyboard side of things, we still have 5V but ground has been severed. Worse still an inductor in series with that trace fell off while I was cleaning the board (a bit too roughly I guess) at reference L9 in the second photo. The clock line seems to be intact, while the data line is severed.
My plan is to bodge these lines back in and put in new ports since the old ones were damages anyway. If that ends up working well; I'll replace one of the ram slots that have been broken off by the seller (thanks /eyeroll) if I can find a replacement.
Question: Isopropyl should neutralize Ni-Cad acid (base?) right? The green corrosion along some traces and pads can be left alone?
I doused the area in 99% isoproyl alcohol to try and neutralize the acid. The PS/2 connectors were pretty corroded themselves and I wanted to clean and see the damage underneath em as well... so they were desoldered and removed. My camera can't get all the detail, but here is the top side: From what I can tell the ground trace has totally been eaten away by the battery acid. The bottom side is thankfully fine. Pretty lucky!
The good news is after probing around I found where the data and clock pins finally end up on the FPGA (is it too early to call this a chipset?) from the mouse port. Looks like the mouse circuit is still intact. On the keyboard side of things, we still have 5V but ground has been severed. Worse still an inductor in series with that trace fell off while I was cleaning the board (a bit too roughly I guess) at reference L9 in the second photo. The clock line seems to be intact, while the data line is severed.
My plan is to bodge these lines back in and put in new ports since the old ones were damages anyway. If that ends up working well; I'll replace one of the ram slots that have been broken off by the seller (thanks /eyeroll) if I can find a replacement.
Question: Isopropyl should neutralize Ni-Cad acid (base?) right? The green corrosion along some traces and pads can be left alone?
