Repair attempt of a Cisco 2960G switch by desoldering and replacing the RAM chip. The fault I am trying to repair is the dreaded instantaneous amber (yellow) upon powerup of the port activity LEDs, and absolutely no activity from the serial console or from the System LEDs.
The video covers step-by-step the whole RAM replacement procedure, where I provide some trick&tips with desoldering braid and capton tape you can use for easier soldering/desoldering RAM chips to/from different motherboards. For the SMD work I use a JBC CD 2BBEW station, which is awesome. For removing the chip a Honton HT-R390 station, and Amtech NC-559 flux (see my related videos).
Here I go over the thought process of trying to narrow down the components which are responsible for the defect, and explain why I am exchanging the RAM chip. As a source for the RAM chips here I use a 256MB memory module, which is normally used for the Cisco ASA5505 series of firewalls. The model number of the RAM stick is: Viking VR4CU326426ETP-MF. The Micron RAM chips from this RAM stick are the same as the one which is used on the Cisco 2960G switch motherboard.
Sorry for the audio, my beard was touching the lapel microphone, causing the scratchy noise, and could not fix it even in editing. Next time I have to take care, that the mike is far away from my beard...
Since the RAM replacement did not solve the issue, next I will have to rework the flash chips. However, with the flash chips I need to buy an external programmer (so far I got only an old EPROM programmer), because the flash has to contain the ROMMON, and without the ROMMON in the flash, the switch would never even attempt to boot. For this first I need to be able to remove two known good flash chips from an other Cisco 2960G so that I can test whether the external programmer is reading the code from the interlaced flash chips properly.
239