BitWiz
Experienced Member
I just received M8340 and M8341 boards from an ebay purchase. When I put them in my PDP-8/E the system did not seem to work properly at all.
I removed the EAE boards and reconnected the main three CPU boards and everything is working again.
After removal I examined the EAE boards and found that it looks like both boards missing the tantalum caps near the bottom of the boards. On the M8341D that would be C33, C34 & C35 (6.8uF @ 35V) and on the M8340E board that would be C35, C36 & C37 (6.8uF @35V).
I cleaned up the contacts and removed what may have been some kind of trace scratch that led to a short and now it is running my rudimentary test.
Should I replace the CAPs? Can I use electrolytics instead of tantalums?
I will run the full maindecs when I get a chance.
Thanks for the help,
Mike
I don't know how to setup the signature line so here is my signature line:
I am a PDP-8 fanatic living in the Chicago area and I am looking for any surplus PDP-8 related hardware and documentation. I am specifically in need of a TC08 or TD8E dectape controller, M933 cables for the RK05, additional TU56s and RK05s, PC08, M8650, programmable timer, DECTapes, RK05 Packs (16 sector PDP-8 style), +10V & -15V or +5V and -15V power supply for the TU56, DECTape spools, TU56 Mounting shelf and spacer block (7408321 & 7408322). Please feel free to contact me if you have any of the above or just to talk.
I removed the EAE boards and reconnected the main three CPU boards and everything is working again.
After removal I examined the EAE boards and found that it looks like both boards missing the tantalum caps near the bottom of the boards. On the M8341D that would be C33, C34 & C35 (6.8uF @ 35V) and on the M8340E board that would be C35, C36 & C37 (6.8uF @35V).
I cleaned up the contacts and removed what may have been some kind of trace scratch that led to a short and now it is running my rudimentary test.
Should I replace the CAPs? Can I use electrolytics instead of tantalums?
I will run the full maindecs when I get a chance.
Thanks for the help,
Mike
I don't know how to setup the signature line so here is my signature line:
I am a PDP-8 fanatic living in the Chicago area and I am looking for any surplus PDP-8 related hardware and documentation. I am specifically in need of a TC08 or TD8E dectape controller, M933 cables for the RK05, additional TU56s and RK05s, PC08, M8650, programmable timer, DECTapes, RK05 Packs (16 sector PDP-8 style), +10V & -15V or +5V and -15V power supply for the TU56, DECTape spools, TU56 Mounting shelf and spacer block (7408321 & 7408322). Please feel free to contact me if you have any of the above or just to talk.