Tips for desoldering a C64 Kernel ROM?

  • Thread starter Thread starter WhyreByter
  • Start date Start date
  • Replies Replies 3
  • Views Views 1818
W

WhyreByter

Member
AmiBayer
Joined
Oct 18, 2010
Posts
176
Country
USA
Region
Washington State
Hi guys...

I finally got a chance to crack open a really nice C64 breadbin to clean the case, and scope out putting JiffyDOS in it, for eventual use with my new 1541 Ultimate-II.

The unit has a good condition box with matching serial #'s and styrofoam inserts, and the unit itself is in excellent shape, inside and out. So, I'd hate to mess it up. :)

Of course, I found that the kernel ROM isn't socketed (unlike just about every other breadbin I've messed with :(). So, I'm debating pulling the chip and putting a socket in.

I really don't want to kill this motherboard, so I'm looking for tips to make this smooth. I've got a fairly high-end solder station, including hot air, to work with. I've done a lot of repair stuff, but only on currently broken things, so the price for messing up isn't so steep. :)

The process I'm looking at using is using the solder sucker, followed by solder braid. The big question is whether I use hot air to remove the chip first, or clip all the leads and pull them one-by-one, or try to remove it after solder sucking. Since I'll be putting J-DOS in it, I'm pretty much OK with losing it...

Thoughts/suggestions?

Thanks!
Robert
 
To make it nice and clean cut it out and suck holes clear (soldering wick), quick, painless (not for IC :)) and the lowest possibility to damage the board. Otherwise solder sucker but it is easy to damage the PCB (scratches etc.) and I would not recommend it.
 
I also vouch for clipping out the pins from the chip prior to use soldering wick and LOTS of flux to easy the task.

To easy even more your experience you can heat the area with hot air station up to no more than 60°C (or you'll burn your fingers holding the board, lol).
 
Thanks... I pulled it out yesterday, and it went pretty well. I clipped the leads and sacrificed the original chip in the name of saving the board.

Went smoothly all the way, except that my replacement eprom didn't work, even with the adapter. It worked fine for ~ 5 minutes, then I changed a setting on my 1541Ultimate and had to reset, and it never worked after that. I tried a different burning of the eprom, but no go. Diagnostic cart pointed to the kernel rom as being the only thing wrong.

Borrowed another original kernel rom from a friend today, and it's up and happily looping through the diagnostics with no problems..! :thumbsup:

Now, I need to figure out why my adapter (quadruple-checked the wiring, and it worked once), or the eprom (a Hitachi HN482764G-2) didn't work right (just for sanity's sake). Open to suggestions on that...

Thanks!
Robert
 
You must log in or register to reply here.
Back
Top Bottom