Repairing second 5200, no video, hot RAM chip

[7800fan]

One of the 8 RAM chips gets rather hot, almost too hot to touch compared to other 7. Could this cause no video issue? Or should I replace the hot chip and look elsewhere?

[+DrVenkman]

Yes, faulty ram can cause a system to fail to boot. Fortunately ram chips are still commonly available on eBay and elsewhere online.

 

On the other hand, there are many possible causes for failure to boot. It’s hard to be sure if ram is the issue. It could be that the chip is hot because it’s being strobed incorrectly by a bad logic chip or the CPU, etc. So in the absence of an oscilloscope or logic probe to check signals on the chips pin by pin, certainly start by replacing that hot chip and see how it goes.

[+-^CrossBow^-]

To easily tell if the chip is getting hot because of another logic problem attached to it...simply swap the chip with another chip to see if the hot stays with that chip or stays in the socket. If you have some canned air, you could turn it upside down and spray it onto the hot ram chip to freeze it and see if you can at least get it to boot?

[7800fan]

Cooling spray didn't work, swapping chip around did move the hot spot around. My temp probe was registering nearly 75'C on 2 of the chips, a tad toasty. I got a set of 8 RAM chips off eBay from Europe and swapped them all. Now my 5200 works.

 

I also had to replace the original cart slot, it didn't work because of gunk inside that I couldn't clean out and the power LED, the old one somehow had broken lead.