Search found 12 matches

by FlaminJoe
Sun Jan 20, 2019 6:43 pm
Forum: PCjr Hardware
Topic: PCJr Motherboard Troubleshooting
Replies: 8
Views: 2262

Re: PCJr Motherboard Troubleshooting

Have you been making anymore progress? Unfortunately no, I've put it on the back burner for the time being as I don't seem to be making any further progress. Also I ended up buying another (this time known working PCjr) which should arrive tomorrow. It was bundled with quite a few extras (2 x keybo...
by FlaminJoe
Thu Dec 27, 2018 1:08 pm
Forum: PCjr Hardware
Topic: PCJr Motherboard Troubleshooting
Replies: 8
Views: 2262

Re: PCJr Motherboard Troubleshooting

Finally making some progress. Turns out it was the 14.3mhz crystal that was at fault which I've now replaced with a spare salvaged from a dead Atari board I have. I'm now getting two beeps consistently and my composite display is picking up a signal whereas before it was getting nothing. Still no di...
by FlaminJoe
Thu Dec 27, 2018 2:00 am
Forum: PCjr Hardware
Topic: PCJr Motherboard Troubleshooting
Replies: 8
Views: 2262

Re: PCJr Motherboard Troubleshooting

It looks like I may have stumbled across the problem. Just when I was about to give up and resign myself to needing to find another motherboard, I thought I would play around with the trimmer pot on the off chance it would do something and it did. Unfortunately my multimeter is a cheapy which doesn'...
by FlaminJoe
Tue Dec 18, 2018 2:29 am
Forum: PCjr Hardware
Topic: PCJr Motherboard Troubleshooting
Replies: 8
Views: 2262

Re: PCJr Motherboard Troubleshooting

alanh wrote:Do you have a JR-IDE? Do you get any POST writes?
Unfortunately no I don't have a JR-IDE. Would be very handy to have it's POST code feature but I'm currently limited to just a multimeter and a logic probe so I feel like I'm flying blind at the moment.
by FlaminJoe
Mon Dec 17, 2018 3:29 am
Forum: PCjr Hardware
Topic: PCJr Motherboard Troubleshooting
Replies: 8
Views: 2262

Re: PCJr Motherboard Troubleshooting

Ok it seems I managed to sort out that little issue. Turns out the 12V pin on the PCjr motherboard was slightly out of alignment meaning it wasn't getting a proper connection to the board hence the lack of voltage. I'm now measuring 12V going in the voltage regulator and 5V coming out and the DS1488...
by FlaminJoe
Sat Dec 15, 2018 9:05 pm
Forum: PCjr Hardware
Topic: PCJr Motherboard Troubleshooting
Replies: 8
Views: 2262

PCJr Motherboard Troubleshooting

Hi all, I recently received a PCJr Motherboard for a PCJr I'm in the process of gathering all the various parts for to one day hopefully having a fully working PCJr system. The motherboard was purchased under the provision it was untested so I assumed it was most likely faulty and it turns out it wa...
by FlaminJoe
Fri Dec 07, 2018 6:53 pm
Forum: PCjr Hardware
Topic: IBM PCjr Circuit Board 3000-0004 REV 1
Replies: 7
Views: 2130

Re: IBM PCjr Circuit Board 3000-0004 REV 1

Yes I found his response quite interesting. He's basically offering it to me for a discount but then what would I do with it? I didn't even know what it was! :lol:
by FlaminJoe
Thu Dec 06, 2018 11:54 am
Forum: PCjr Hardware
Topic: IBM PCjr Circuit Board 3000-0004 REV 1
Replies: 7
Views: 2130

Re: IBM PCjr Circuit Board 3000-0004 REV 1

I just received this response from the seller: It was definitely pulled from a PC jr. After additional research, I am told it goes to a Tekmar/Quadram Drive 2 expansion unit. I don't know if that is true. I raised the price, not because you asked about, but because there do not seem to be any others...
by FlaminJoe
Thu Dec 06, 2018 2:10 am
Forum: PCjr Hardware
Topic: IBM PCjr Circuit Board 3000-0004 REV 1
Replies: 7
Views: 2130

Re: IBM PCjr Circuit Board 3000-0004 REV 1

Yeah I figured it didn't seem right. Even if it fitted into the side-card connector it seems like an odd PCB to having hanging out the side.

Out of further curiosity I've emailed the seller to see what's up.
by FlaminJoe
Wed Dec 05, 2018 6:28 pm
Forum: PCjr Hardware
Topic: IBM PCjr Circuit Board 3000-0004 REV 1
Replies: 7
Views: 2130

IBM PCjr Circuit Board 3000-0004 REV 1

Hi all, I saw this on eBay and out of curiosity I'm wondering what it is. The seller claims in the listing "Pulled from working PC Jr." and while I don't have a full grasp of the inner working of the PCjr and it's attachments, I'm stumped as to where it would fit in and what purpose it ser...