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macintosh lc- no sound, no video, no hd?

M

Mr. Engino

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Jul 31, 2016
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about a week ago I had purchased a Macintosh LC on eBay; it was listed as not working. received package, plugged in monitor, keyboard, and mouse, and turned it on. other than the fan, there was no sound; chimes of death or otherwise. there was also no video. I opened the mac, and there was no hard drive whatsoever. my question is: is my macintosh damaged, or is it just because there is no hard drive?
 
Did the LC suffer from capacitor issues? If not, check the PSU. Even if the fan is running, the voltage may not be high enough to boot the system to the blinking questing mark folder.(I've powered some fans with about 3V, which is not enough to boot the Mac. Other times, if the fan is in the PSU, it can run, even though the rest of the supply is dead. I don't know why, but I've had it happen.
 
The capacitors are most likely expired. I have several 68k macs (including an LC III) which exhibited the same problem of a black screen and no boot until all of the capacitors were replaced.

You'll want to get those old caps off as soon as possible because the electrolyte leaks out the bottom and will eventually seep into the motherboard and cause damage.
 
ok. I have taken apart my mac and looked at the mobo. I think the capacitors are leaking; and unfortunately I do not have the money or the tools to fix it...
 
It's not overly expensive or difficult to replace the SMD caps, you can do it for less than $40.

All you really need is the small pile of replacement caps, a small pair of pliers and a semi-decent soldering iron.

The other option is to send the board to someone on this forum, I think there are several people willing to recap it for you for a fee.
 
I was feeling generous this morning and there's not a lot of electrolytic's on the LC motherboard so I sent the op an offer and we are in agreement

soooooo lets hope that's all that is needed (well aside from a drive), I know on my LC2 not ALL the caps were rotten and when you could get it to boot it would whistle and pop from the speaker and get unstable pretty quick
 
I'm not sure if it was just early SMT chemistries, a bad run of caps, or what, but especially the low-end 68K Macs seem to have motherboard capacitor issues. At this point, even if you *can* boot it, I'd assume all caps are dead and/or dying. If they leak and you don't notice it, it'll degrade the motherboard to the point where the traces easily lift.
 
yea I make a decent amount of hobby money by recapping old game consoles and computers from the early 90's, not great amounts of money but enough to buy new toys while making someone very happy

this case I know what its going to take to recap his board, I get the caps for darn near free since I work as a EE at a manufacturing facility I was like screw it, its going to take one baby naptime to swap these out so I said hey pay for postage to and from me ill knock it out lol

also when we moved a few years back to a larger plant, they were throwing away reels of 2512 sized 10 and 1 uf ceramic caps so I grabbed a couple reels each (a lifetime's supply and probally a few hundered dollars) so whenever I can I replace 10's and 1's with ceramics which will never leak and given the large size fit SMT and though hole electolytic footprints like a champ ... my gameboy, and my mac LC2 is full of them
 
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I did the same with solid tantalum surface mount caps in my LC 2 and Classic 2, since we had them on hand at work. They don't look the same, but it's on the inside of the machine, so who cares?
 
yea and they last a butload longer

ceramics last 10x as tant's and tant's last 10x longer than electrolytics so that put's them in the 100's of years if not subjected to physical stress, works for me
 
Are we talking the original stock LC? If so you are limited to 512x384 video which means forget using an LCD or even the cheap mac to pc video adapters that start at 640x480 resolution. With a VRAM upgrade you can do 640x480 and most likely need SOG monitor or the colors are off.

No sound could mean the speaker is disconnected or more likely the capacitor in that circuit is dead. Once the capacitors go the unit will be dead (easy fix). My first LC (LC 3 actually) worked for about 1 bootup when I heard a whistling sound from the speaker and it never booted again until I redid all the aluminum capacitors.
 
I use a cheap LCD HD TV, it takes all kinds of crap including 240p from the component ports and 512x384 on the vga
 
glitch said:
I'm not sure if it was just early SMT chemistries, a bad run of caps, or what, but especially the low-end 68K Macs seem to have motherboard capacitor issues. At this point, even if you *can* boot it, I'd assume all caps are dead and/or dying. If they leak and you don't notice it, it'll degrade the motherboard to the point where the traces easily lift.
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Capacitors in 68k macs at this point are 25-30 years old, that's an eternity for an electrolytic capacitor. Even if those machines used top of the line radial capacitors instead of SMD, they'd still be bad. PC motherboards from the same time frame have similar issues with worn out capacitors.
 
GiGaBiTe said:
Capacitors in 68k macs at this point are 25-30 years old, that's an eternity for an electrolytic capacitor. Even if those machines used top of the line radial capacitors instead of SMD, they'd still be bad. PC motherboards from the same time frame have similar issues with worn out capacitors.
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Most of the issues I see on 70's hardware is shorted tantalums and electrolytics that have completely dried out. Now and then you'll find one that suffered a short, popped the vent, and sprayed electrolyte on everything. I've still got plenty of 1970's electrolytics in great shape, though.
 
dunno about the LC, my LC2 boots fine without a battery, it just takes for ever to do a slow ram count and starts up in black and white mode (I ended up wiring a dual AAA holder in it for 1.49$ instead of darn near 20 for a 1/2 AA 3 volt cell)
 
Osgeld said:
dunno about the LC, my LC2 boots fine without a battery, it just takes for ever to do a slow ram count and starts up in black and white mode (I ended up wiring a dual AAA holder in it for 1.49$ instead of darn near 20 for a 1/2 AA 3 volt cell)
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Where the heck do you pay $20 for a 1/2 AA lithium battery? You can get them for $5.70

http://www.newark.com/tadiran-batteries/tl-2150-s-bp/cylindrical-battery-lithium-1ah/dp/87F6402

I use these in all of my vintage macs and they hold their capacity for a ridiculous period of time. One of my Macs has the original Tadiran cell in it from 1993 and it still has something like 2.5v out of 3.6v.
 
Where the heck do you pay $20 for a 1/2 AA lithium battery? You can get them for $5.70
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oh that's cute its only 6 bucks, lets look at checkout oh cant send lithium batteries though the post office, least every time I have tried to buy one from digikey newark and mouser the website will let me then I get an email about 2 days later saying UPS or fedex only, boom instant 9$ shipping fee so already we are up to 15 bucks, which is what they cost at radio shack and batteries plus ... + tax

even if they were only 6 bucks with no tax and shipping you can get 2x AAA holders for 1.49$ at most home improvement stores and 2x AAA's will run a pram for years
 
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