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Apple collection, new members

F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
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I've just recently rescued several old apple machines from the local pawn shop, all in cosmetically pretty nice condition. The machines are as follows:

Apple IIe
Apple IIc
Macintosh 512k
Macintosh SE

They are all in working order except the Mac SE, which I am still trying to diagnose. Currently I suspect the power supply as when the unit is powered on i hear a repeating clicking noise from the internal speaker and the fan doesn't turn on nor does the screen light up. Perhaps a diode is shorted and the overload protection in the supply is kicking it off..
 
MacTech68

MacTech68

macrumors 68020
Mar 16, 2008
2,393
209
Australia, Perth
Anything shorting the output of the power supply could cause the ticking MacSE, even within the power supply module itself.

However, the most common problem I'd see (way back then) was the Line Output Transformer (L.O.P.T.) shorting and additionally taking out the Horizontal Output Transistor (H.O.T.).

Given the age now, it could be anything. What you're hearing is the Switch Mode Power Supply protecting itself and shutting down. It then has no option but to try powering on again, repeating the sequence, hence the tick, tick, tick.

Edit: perhaps I shouldn't have been so hasty, and should have read the last line of your post. :(

Edit 2: A give-away sign of the LOPT & HOT is if the HOT heatsink is discoloured blue-ish/purple. The HOT is one of the two heatsinks on the top edge of the Analog Board.
 
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F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
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Roderick Usher said:
Out of curiosity, what cards are in the IIe? Also, pics?
Click to expand...

appears the only card installed is the disk controller card. as for pictures I will do that when I get the time to..

My immediate project will be to attempt to diagnose the ailing Mac SE.
 
F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
34
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MacTech68 said:
Anything shorting the output of the power supply could cause the ticking MacSE, even within the power supply module itself.
Click to expand...

I pulled the power supply and tested it while running a 12v fan, the only thing that looked off was the -12v line measuring only about -9.5v with no load.
 
F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
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probably could without much trouble, just 5v 12v and -12v. But I'm still not sure it's the power supply at fault since it seems to run ok when not in the unit
 
MacTech68

MacTech68

macrumors 68020
Mar 16, 2008
2,393
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Australia, Perth
F. Hopper said:
probably could without much trouble, just 5v 12v and -12v. But I'm still not sure it's the power supply at fault since it seems to run ok when not in the unit
Click to expand...

True, that would be my initial diagnosis, however, you might want to check the PSU with the load of just a hard drive.

Another thing to try would be to re-assemble the machine but leave the floppy drive and hard drive disconnected.

It's possible that the PWM in the PSU has a bad electrolytic cap or bad caps on the output which prevent the PSU from delivering the required power output.
 
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F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
34
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plugged a hard disk into the psu and flipped the power switch, all seems well. Checked out the electrolytic caps in the psu as well, no visible signs of leakage or stress.

I'm checking into the schematic of the analog board now to try and isolate likely failure points
 
O

OSX-SUX

macrumors newbie
Mar 19, 2010
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Roderick Usher said:
Out of curiosity, what cards are in the IIe? Also, pics?
Click to expand...

One of my IIe's is full of cards. It has the 5x processor accelerator (takes it from 1 Mhz to 5Mhz I believe). Playing Wings of Fury at 5x is almost impossible, lol. I apologize if my numbers or terminology is off, I'll have to pull my boxes out again and see. I think it has a clock card too and modem, or maybe just a modem.

I think I have several 80 column cards. Basically a huge cache of old Apple goodies, II, IIe, II+, books, games, joysticks, disks, systems, unopened games, etc. A couple Mac cases that had hopes of becoming something else (aquarium, speakers, etc)

Problem is that it seems too big to sell on Ebay and a friend has the same sized collection and we talked about pooling them together for the mother lode auction. I just don't have time to break it up into smaller working systems and am ready for one person to take it all, lol
 
F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
34
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just pulled a working iMac and an old apple dot matrix printer out of the same shop.
 
F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
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Indeed..

Now I just wish the point of failure was more clear on this Mac SE. I think it could be in the flyback driver or transformer as I hear the transformer make some noise before the suppy safety shuts it off.
 
M

max¥¥

macrumors 6502a
Aug 7, 2008
640
29
Over there....
F. Hopper said:
Indeed..

Now I just wish the point of failure was more clear on this Mac SE. I think it could be in the flyback driver or transformer as I hear the transformer make some noise before the suppy safety shuts it off.
Click to expand...

i have heard that people often think that a failed flyback is problems with other parts of the machine (psu ect)
 
MacTech68

MacTech68

macrumors 68020
Mar 16, 2008
2,393
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Australia, Perth
max?? said:
i have heard that people often think that a failed flyback is problems with other parts of the machine (psu ect)
Click to expand...

Indeed, way back when.... the flyback was the most common problem.

Seems Donberg no longer stock the 157-0042C. A quick google search shows a lot of vendors appearing to sell them.

Although it may be cheaper to pick up an old 128K, 512K or Mac Plus and use it's transformer, so long as it's at least a 157-0042B or 157-0042C.
 
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F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
34
0
i thought of maybe having some fun and building a 'GhettoMac SE' by building a new case around parts from another screen and eliminating the old analog board all together, but it seems the video signal from the SE logic board is some kind of TTL high clocked signal that would probably be very difficult to convert to a format that a screen today could use..
 
K

kbfr08

macrumors 6502
Mar 16, 2007
462
29
F. Hopper said:
i thought of maybe having some fun and building a 'GhettoMac SE' by building a new case around parts from another screen and eliminating the old analog board all together, but it seems the video signal from the SE logic board is some kind of TTL high clocked signal that would probably be very difficult to convert to a format that a screen today could use..
Click to expand...

You could try this TTL-to-LVDS circuitry
http://en.esskabel.de/adapter/datasheet/ada-lvds-tx-twin/15

Also, building a new case around a screen looks incredibly ghetto. I put a 15" HP laptop into a dell 17" lcd monitor, the motherboard fit fine, but the LCD's lamps couldn't be powered by the laptop, so I had to fit the 15" lcd into the 17" case. It looks sort of like an imac, but not professional at all. With that said, a few of my friends have offered to purchase it because "it's cool".
 
M

max¥¥

macrumors 6502a
Aug 7, 2008
640
29
Over there....
kbfr08 said:
You could try this TTL-to-LVDS circuitry
http://en.esskabel.de/adapter/datasheet/ada-lvds-tx-twin/15

Also, building a new case around a screen looks incredibly ghetto. I put a 15" HP laptop into a dell 17" lcd monitor, the motherboard fit fine, but the LCD's lamps couldn't be powered by the laptop, so I had to fit the 15" lcd into the 17" case. It looks sort of like an imac, but not professional at all. With that said, a few of my friends have offered to purchase it because "it's cool".
Click to expand...

that could work on my plus? right, now where did i put the plus...:rolleyes:
 
R

Roderick Usher

macrumors regular
Dec 9, 2006
182
1
OSX-SUX said:
One of my IIe's is full of cards. It has the 5x processor accelerator (takes it from 1 Mhz to 5Mhz I believe). Playing Wings of Fury at 5x is almost impossible, lol. I apologize if my numbers or terminology is off, I'll have to pull my boxes out again and see. I think it has a clock card too and modem, or maybe just a modem.

I think I have several 80 column cards. Basically a huge cache of old Apple goodies, II, IIe, II+, books, games, joysticks, disks, systems, unopened games, etc.
Click to expand...
That's a tantalizing description. I'd say it's worthwhile to at least go through and pick out the good stuff. Aside from the obviously valuable items like unopened software and working systems, you might have some relatively uncommon cards (like the ThunderClock Plus or Novation Apple-CAT). And an original Apple ][... serious potential moneyhats!
 
F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
34
0
Thanks to the Dayton Hamvention, I have once again added a trunk load of new machines to my collection. Since i'm still not home from the trip I don't know the exact details of the machines yet, but two are g4 quicksilvers, one is a g4 graphite, two beige powermac g3's, some kind of powerpc workstation server, and a macintosh IIcx.
 
F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
34
0
post is a bit stale I see, but I just got a 'broken' mac se/30 off ebay for 50 bucks or so to discover the pcb that runs the filament and ion guns on the back of the tube somehow came off, and someone managed to shove a floppy disk into the disk drive with a shutter off a disk still stuck in it, which compounded the problems with a jammed in disk..

However, it's now back in excellent working health after some minor surgery to repair the disk drive and a powerup with 32mb of memory, and soon to replace the hdd with a 200mb. Looks like my plans to use this unit to fix the ailing Mac SE and its blown up analog board have changed.

I have, however, determined that there is a short in the SE's analog board on pin 10 and ground, and that diode CR3 is getting very hot quickly.. not sure if CR3 is bad yet but might replace it anyway being where it is in the circuit.
 
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F. Hopper

F. Hopper

macrumors member
Original poster
Oct 16, 2008
34
0
indeed, this is the conclusion I came to as well (cr2, cr3, or q2), but its nice to see another source that reinforces my diagnosis. I checked cr2 out of circuit with a multimeter and it seems to be functional, however i wouldn't think a test in circuit at that point would read 0.00 ohms, unless q2 is blown and the circuit is closed..
 
A

Archon Gold

macrumors 6502
Jun 7, 2009
331
0
Canada, Ontario
Good luck on your collection, seems like your local pawnshop is pretty nice, mine has no electronics.

I am also currently having a problem with one of the macs that I received, It's a 1Ghz eMac (PC100) but wont receive any power at all, I suspect that the PAV board is dead as I swapped out the down converter power supply with one that worked but it still refuses to receive any power.

The worst part is that I even have the original box, keyboard, and mouse for the computer. Oh well, might make a nice display piece.
 
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