68kMLA Classic Interface

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Macintosh Classic horizontal line
Posted by: Retro Rider on 2018-04-26 18:14:12
I got 2 Macintosh classic's (with some other stuff) not so long ago, and when I booted up the Mac classics, they both had this line (see picture, although one of them was a little dimmer. Also one in the pic has had varying results). One of them crapped out while I was trying to fix it and smelt like burn, but the other one still shows a line. I haven't really been able to find anyone else with this problem, so how do I fix this?

IMG_2648.JPG
Posted by: MOS8_030 on 2018-04-26 18:41:43
Check out the PDF repair books here: http://www.maccaps.com/MacCaps/Repair_books.html

🙂

Posted by: Retro Rider on 2018-04-27 09:10:24
Check out the PDF repair books here: http://www.maccaps.com/MacCaps/Repair_books.html

🙂
I think I found my issue (in Dead Mac Scrolls pg. 50) but I can't find the capacitors it lists (Q4, Q2, R3, and CR15) on the analog board.
Posted by: Verault on 2018-04-27 10:21:38
Retro Rider, I am having the same issue on my compact mac, started a thread a couple weeks back:





let me know what you find out! I looked at the dead mac scrolls, issue with mine is horrizontal bar but no BONG.
Posted by: Retro Rider on 2018-04-27 11:16:41
Retro Rider, I am having the same issue on my compact mac, started a thread a couple weeks back:





let me know what you find out! I looked at the dead mac scrolls, issue with mine is horrizontal bar but no BONG.
When I was playing around with mine (I think it was when I installed some more ram), I also got a broken line. I also get no bong, but it might be the speaker because on my se/30 (my only sort of functioning 68k mac) it doesn't do a bong and won't play any sound at all.
Posted by: Verault on 2018-04-27 11:30:47
Mine is a mac Plus. Was working but when I got it had major battery corrosion to the metal chassis and analog board. the logic board is fine. The analog board was working before I started any cleanup. I was using the machine. But when I gave it a thorough cleaning , I got the horizontal bar. Replaced all electrolytic caps and rifas. Tried another known good flyback, still nothing. Tested all IC's, they are fine.  Time to movie to the transistors and diodes I guess.
Posted by: Retro Rider on 2018-04-27 11:38:25
I still don't know where the capacitors are I need to replace, it doesn't say anywhere online, and I'm thinking about trying the analog board from my SE FDHD.
Posted by: Verault on 2018-04-27 11:48:44
whats your email, I have something that may help you
Posted by: Dog Cow on 2018-04-27 11:57:04
I also get no bong, but it might be the speaker because on my se/30 (my only sort of functioning 68k mac) it doesn't do a bong and won't play any sound at all.
No, that's much more likely a symptom of failed or failing capacitors-- as is the failed vertical deflection on the CRT. I have had this happen on several Macs. If you put your ear to it and turn the volume up, you may be able to hear a sound.

Looks like you've got 2 old Macs ready for new capacitors. 🙂  
Posted by: Verault on 2018-04-27 11:57:56
also, your horizontal line is very bright (turn down the brightness alot while diagnosing as to not burn the crt) you may want to just resolder every contact on your flyback transformer. When I swapped my flyback out and boot it up for the first time the horizontal bar was EXTREMELY Bright! with a hum. I took the analog board back out and realized one of he pins to the flyback didnt have the best connection, I added a touch more solder and the horizontal bar was a little more dim and broken as before I swapped it.
Posted by: Retro Rider on 2018-04-27 12:07:41
I'll have to look at all of this when I get on
Posted by: Retro Rider on 2018-04-27 17:39:18
I was messing with one of the other classics when I plugged it in and it blew my room's fuse
Posted by: Verault on 2018-04-27 19:11:21
what? Not sure what you mean? the short in your MAC blew your house fuse?
Posted by: Retro Rider on 2018-04-27 19:33:09
what? Not sure what you mean? the short in your MAC blew your house fuse?
I plugged in the mac classic, and when I plugged it in it sparked and everything in my room turned off.
Posted by: Verault on 2018-04-28 07:37:04
that would only happen with a short. if you changed any components are you 100% sure you didnt put them in backwards?
Posted by: Verault on 2018-04-30 05:26:46
So I made an order on digikey for replacement transistors and some power diodes. I got them off that list I sent you. I would like to find a listing for every single resistor, diode, component etc for the Analog board but I cant seem to find one.
Posted by: Retro Rider on 2018-04-30 09:29:27
that would only happen with a short. if you changed any components are you 100% sure you didnt put them in backwards?
I didn't change anything though
Posted by: Retro Rider on 2018-04-30 09:29:47
I booked an appointment for the apple store lol
Posted by: Verault on 2018-04-30 09:30:09
that would be funny.
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