Thread
Macintosh TV in need of repair - need advice
Our Macintosh TV worked great last week but this week we have a similar issue like Krye. Tried everything mentioned here and still no led green light but has the same subtle chirp when switching on...our difference is when leaving it alone for a while it makes a louder sound like a regular tv sound turning on but still no screen...trying it immediately afterwards it goes back to the subtle chirping sound like that described by Krye...thanks ahead for any further thoughts/ideas.
I am no longer convinced that the green light is supposed to turn on when you remove the logic board. I know that it does on 5500s, but we need to verify this for 5xx series Macs like the Mac TV. (The Mac TV is most equivalent to an LC 520)
@alex
I'm stuck on this for now. I've had my eye on eBay for some replacemnt parts. The only thing I've found so far is an LC520 analog board and an LC520. I was hoping to swap out the analog board, but none of them work. 3 dead board sounds too hard to believe. I've tried everything else. The Mac TV and the LC520 both do the same thing. They chirp when power is applied, but that's it. They just don't turn on.
Let me know how you make out.
I'm stuck on this for now. I've had my eye on eBay for some replacemnt parts. The only thing I've found so far is an LC520 analog board and an LC520. I was hoping to swap out the analog board, but none of them work. 3 dead board sounds too hard to believe. I've tried everything else. The Mac TV and the LC520 both do the same thing. They chirp when power is applied, but that's it. They just don't turn on.
Let me know how you make out.
because..... the logicboard is at fault.
You need 3 things for an LC5XX machine to startup:
1. a good analog board, because without power, it wont do jack shit. If you hear a slight chirp when switched on/plugged in, Thats a pretty damn good indication that the power supply is starting up.
2. a good logic board, Why? because if the power management circuit isnt working, the analog board wont latch out of standby.
3. a good keyboard/cable. How else is the logic board going to get a power signal? hehe.
You need 3 things for an LC5XX machine to startup:
1. a good analog board, because without power, it wont do jack shit. If you hear a slight chirp when switched on/plugged in, Thats a pretty damn good indication that the power supply is starting up.
2. a good logic board, Why? because if the power management circuit isnt working, the analog board wont latch out of standby.
3. a good keyboard/cable. How else is the logic board going to get a power signal? hehe.
It troubles me that the power light does not turn on when the logic board is removed, because I was under the strong impression that the power light turns on in this condition if the analog board is good. That would point to an analog board issue.
Can anyone verify what happens when you plug in and switch on a 5xx Mac without a logic board installed? On a known-good 5xx Mac, does the power light turn on? I'll be quite embarrassed if it doesn't.
Can anyone verify what happens when you plug in and switch on a 5xx Mac without a logic board installed? On a known-good 5xx Mac, does the power light turn on? I'll be quite embarrassed if it doesn't.
Well my color classic does nothing with the logic board removed. Ill go plug in my LC575 and find out.
Nope, NO power light without logic board. LC575. Put the logic board back in, press power key on keyboard, bong it fires up.
Oh my god, I am really sorry I have mislead some people in this thread.
Not a problem. I'll try anything at this point.
its not a problem, theres no way to know unless you try, and i did. hehe.
Agree with techknight and krye...never any worries.
Sweet! Just scored a working 575 on eBay for $60 bucks w/keyboard and mouse, 36 MB RAM 160MB HD.
See, patience is the key. It's been 5 months since I picked up the Macintosh TV. I knew if I kept my eyes on eBay long enough, I'd find a suitable donor.
Can't wait to get it so I can swap the guts! Woo haa haa haa!
See, patience is the key. It's been 5 months since I picked up the Macintosh TV. I knew if I kept my eyes on eBay long enough, I'd find a suitable donor.
Can't wait to get it so I can swap the guts! Woo haa haa haa!
hey post your ad,,, I've been scouring ebay for a LC575.
If I got a working machine like that, I'd keep it. So rare are Macs that already work...
My LC575 has shipped. I'm going to swap the guts when it arrives. Hopefully with that working machine, I can pin point if it's the other analog board or logicboard that's bad.
Shame no! Save that poor LC!
was the ebay ad titled LC 575 or was it called something else,
no harm in posting the ad now since its already shipped, its not like i'll offer the guy 10-20 bucks more or anything
no harm in posting the ad now since its already shipped, its not like i'll offer the guy 10-20 bucks more or anything
I'd much rather have a working Macintosh TV than a working 575 even if the guts are the same. It's all about the black enclosure! True, the Macintosh TV used a "modified" 575 board, but I'm not going to actually watch TV on it.
On the bright side, I also have a 520 that doesn't boot that also might benefit from this conquest. I can't figure out if it's the analog board or the logicboard that's dead. Maybe after all is said and done, I have something left over that I can use to resurrect the 520. If I can get two machines working by taking apart the 575, then it's a win-win.
On the bright side, I also have a 520 that doesn't boot that also might benefit from this conquest. I can't figure out if it's the analog board or the logicboard that's dead. Maybe after all is said and done, I have something left over that I can use to resurrect the 520. If I can get two machines working by taking apart the 575, then it's a win-win.
by the way i have a 575 logic board that needs to be re-capped, with a Full 040 already in it, if you are interested.
Got the 575 in the mail last night. I opened it up and cleaned out the dust bunnies. I had a look a the analog and logic boards. Everything looks good. No leaky caps. I plugged it in and fired it up. Works like a charm.
Hopefully this week I'll have time to use it as a test bed for the boards inside the Macintosh TV and 525 that I have. That way I can find out exactly what works and what needs to be fixed. In the end I know I can at least take the guts out of the 575 and put them in the Macintosh TV enclosure.
Hopefully this week I'll have time to use it as a test bed for the boards inside the Macintosh TV and 525 that I have. That way I can find out exactly what works and what needs to be fixed. In the end I know I can at least take the guts out of the 575 and put them in the Macintosh TV enclosure.
Here it is. Pretty filthy, but it works.
It was pretty dusty inside.
I can't wait to take it apart and test my other boards. I plan on taking a bunch of measurements on the good analog board and then compare them to the Mac TV and 525 boards. Maybe I'll be able to identify the point of failure.
It was pretty dusty inside.
I can't wait to take it apart and test my other boards. I plan on taking a bunch of measurements on the good analog board and then compare them to the Mac TV and 525 boards. Maybe I'll be able to identify the point of failure.
Chirping or ticking means the power supply is trying to come up, but detecting a fault condition and shutting down, only to repeat a moment later. This means several things. First, the primary side of the power supply and chopper transistor are ok, otherwise the fuse would be blown and there would be no action at all. Next, either something connected to the power supply has a short, or the short is in the output section of the power supply itself. I'm not familiar with the internals of these particular machines, is the monitor powered by (or part of) the power supply? If so, I would suspect the horizontal output transistor. Otherwise, I would start by checking the rectifiers and electrolytic capacitors in the power supply.
Thanks. I'm definitely going to take some measurements this weekend and see what's what.
I got the Performa 575 parts moved into the Macintosh TV and it's up and running.
I used the Performa 575 as a test bed for the Mac TV analog/logic and the LC 520 analog/logic, as well as the extra analog board that I bought.
As it turns out:
- the Mac TV analog and logic boards are both dead
- the LC 520 analog is dead but the logic is good
- the extra analog board that I picked up is dead too
The Mac TV must have been hit by lightning or something, because everything in it was toast. Analog dead. Logic dead. The CD-ROM wouldn't read disks. It would split them right out. The flopy drive too didn't seem to work. It just complained that disks were unreadable, and then failed to format them. The hard drive was dead too. I even swapped out the CRT becasue the one in the Mac TV was burned in. You could see the menu bar at startup.
Also, the guns were misaligned becasue none of the colors matched up. The display was slightly rotated and jammed up to the top left hand side.
I think the only thing I got out of it was the enclosure.
In the end, it's good to finally see it up and running after 5 months of trying to get parts for it.
I used the Performa 575 as a test bed for the Mac TV analog/logic and the LC 520 analog/logic, as well as the extra analog board that I bought.
As it turns out:
- the Mac TV analog and logic boards are both dead
- the LC 520 analog is dead but the logic is good
- the extra analog board that I picked up is dead too
The Mac TV must have been hit by lightning or something, because everything in it was toast. Analog dead. Logic dead. The CD-ROM wouldn't read disks. It would split them right out. The flopy drive too didn't seem to work. It just complained that disks were unreadable, and then failed to format them. The hard drive was dead too. I even swapped out the CRT becasue the one in the Mac TV was burned in. You could see the menu bar at startup.
Also, the guns were misaligned becasue none of the colors matched up. The display was slightly rotated and jammed up to the top left hand side.
I think the only thing I got out of it was the enclosure.
In the end, it's good to finally see it up and running after 5 months of trying to get parts for it.
I need a clapping emote. Well done!
Thanks.
There's a whole writeup and walkthrough on my hobby site if you want to check it out: http://appletothecore.me/files/mac_tv_restoration.php
There's a whole writeup and walkthrough on my hobby site if you want to check it out: http://appletothecore.me/files/mac_tv_restoration.php
Congrats!
Great write up on your site as well! Thanks for taking the time to do that. You've inspired us to take another shot at ours.
Great write up on your site as well! Thanks for taking the time to do that. You've inspired us to take another shot at ours.
Congrats,
What are your projects for the remaining two units ??
What are your projects for the remaining two units ??
I might just keep all the spare parts as backup. Most of it's dead.
The only thing left from the 575 is the CD-ROM drive. The case is in bad shape. As soon as I touched the front bezel, it just fell off. Most of the clips that hold it in are broken. Same as the back I/O panel, one of the clips is broken off.
As far as the LC 520, it's the floppy drive, logic, and CRT.
The only thing left from the 575 is the CD-ROM drive. The case is in bad shape. As soon as I touched the front bezel, it just fell off. Most of the clips that hold it in are broken. Same as the back I/O panel, one of the clips is broken off.
As far as the LC 520, it's the floppy drive, logic, and CRT.