Recent content by andy2k68kMLA

Hello all, Has anyone ever tried to adapt a standard ATX power supply to an older power Macintosh? The power supply failed on my 7300/200 (I hope it didn't take the whole computer with it). I noticed that the ATX power connector fits the main power feed (on7300) perfectly and plugs in even. Has...

Okay thanks for the info. I tried with two matching sticks installed too same result as having all 4 installed

Hello everyone I'm trying to troubleshoot a 1MB logic board (820-0174-C). It doesn't chime only does what I posted in the video. I tried reseating ram, booting only with 1 stick of RAM, etc. reseating and cleaning hi and lo ROM DIPS. Voltages are good from a good, working analog board. The -5...

Thanks for your response. I read too that Apple advises against composite SIMMS? Is that correct, how would you know if it is?

Sorry if this is a duplicate post. I really did try to search the forum before posting. I have a 1mb Macintosh Plus and I would like to upgrade it to 4mb of RAM. It says 150 ns or faster 30 pin simm. I've seen memory for a SE 2 plus, listed as, 4x 1MB 30-Pin 80ns FPM Memory SIMMs on fleabay...

Thanks TK I was thinking the same exact thing. I'll try to upload a video of what it's doing when I get off of work. Do you (or anyone else) know of a document that explains the logic board circuits. Something similar to the well written manuals made by Lee and Pina?

Thanks TechKnight. Do you have any other ideas / suggestions for troubleshooting the logic board? I have access to a nice oscilloscope? I've tried removing all memory expect one slot. Removed and cleaned all socketed IC's. Any other ideas?

Thanks so much for checking that for me, seems odd but normal. Any other ideas as to what might be wrong with the logic board. I've heard the TSM chip and -5 volt regulator fail on the logic boards. The -5 regulator seems good. Anyway to test the TSM DIP IC? Any other logic board testing...

Hey guys, I had a break through (I think/hope). I bought another analog board but it had the same exact problem when I swapped it out with a different good AB. Tightly spaced horizontal lines and everything. So I started looking at the logic board. I measured all the caps and found C6 a 33 uf...

Okay I can give that a try. How do you know when U3 the optocoupler is bad? I've heard it can cause the flubbing. I will try posting a video of it to make sure we're on the same page. Thanks for your help! Any other tests or voltage measurements etc that I can do on J1? Will flubbing usually...

Oh and replaced Q8 SCR crowbar TO220. Also, I've measured just about every diode, resistor, capacitor, inductor on the AB. None of the diodes are shorted or resistors open. All the new caps (and old) seem to be okay and measure high resistance. Q8 never gets hot indicating something is truly in...

Ever heard the phrase no good deed ever goes unpunished? Anyways, I own a not so long ago working Macintosh Plus 1 MB. :( I had recapped it with all new electrolytics. After I recapped it. I powered it up, it chimed and seemed like it was working, then about 8 seconds in started flupping...

Awesome! I actually received the answer I wanted to hear for a change (instead of being disappointed). Thank you guys for your help!

I looked on the internets but couldn't find a conclusive answer. Are USB keyboards or mice supported under Mac OS 9 or earlier? I want to buy a G3 tower for cheap to run Mac OS 8 or 9. The G3 has native USB 1.1 drives. So I guess my question is will any version of classic Mac OS (9.1 or earlier)...

Cool Well I guess that seals the deal. You can get one new for about $235. Clearly it works well.