Dead Macintosh TV

[bluetree]

Greetings everybody
 

My Macintosh TV hasn't been working for almost two years now. It just doesn't turn on at all, no light, no sounds. It's a shame! I used it all the time for playing NES and other old video games. I found it on eBay in 2012 for around $70 with the black keyboard and mouse included. I proceeded to upgrade the ram to the maximum 8mb and it worked well. The last few months using it the sound was starting to get weaker. The entire time I owned it, the right speaker never produced sound. Then after not being used for a few weeks, it ceased to turn on.

I'm just looking for some advice on what is the likely cause of it not powering up. 

 

[Schmoburger]

Sounds like a cap issue by the fact the sound was gradually deteriorating... I have a half dozen 5xx-series machines and they all have bad caps that cause all sorts of anomolous behaviour.

Can you "hear" the machine get power when you switch the hard power rocker? Either the thud of the CRT degausse or an electrical "squeak"? If so, it is highly likely to be logic board needing a recap.

 

[LazarusNine]

In my admittedly limited experience, I also think it sounds like some capacitors need to be replaced. I've seen deterioration of a similar kind in my Macintosh Classic and haven't gotten around to replacing the caps on it yet - I need to get on that.

 

[Byrd]

If you can source a donor 520/575 for parts, do so - you can then make troubleshooting a much easier experience by switching things like PSUs, motherboards around

 

[snuci]

Try checking the PRAM battery with instructions here: http://tim.id.au/laptops/apple/legacy/macintosh_tv.pdf  There's also a reset button on the motherboard.  try that too.  On the odd occasion, it will act dead without resetting.  Unfortunately, that document doesn't mention the reset button.

 

[uniserver]

the problem is when you run the CC or the MacTV or the 840av till it dies, most of the time its going to need addational Trace/Via + caps to work again.

That cap goo spills out and causes a plethora of issues.

 

[bluetree]

thanks for the replies and info. Tomorrow I'm going to pull the motherboard and see if anything leaked. The last I saw when I upgraded the ram, the board didn't have any gross looking caps. Could a dead pram battery cause it to not start? I think it is one of the square shaped batteries with velcro on it. First I'll see if it makes any noise at all when I plug it in again

 

[eraser]

As an owner of a Mac TV I will guarantee that it is capacitor related.  Even if you get this machine to boot again you SHOULD NOT use it until it is recapped.  You will destroy it by doing so.

 

[matacao]

Thanks for answer I have the same problem with my Mac TV, I will recap the motherboard and maybe the analog board.

 

[MinerAl]

Uni, isn't the sound board for the TV subsystem particularly packed with caps?  I know the sound on mine was the first thing to go...

 

[dougg3]

I'm not uniserver, but yes, the TV sound board is packed with SMT electrolytic caps. Luckily the whole board is a common TV repair part. I got a new one on eBay for pretty cheap. I added sockets on the TV board so that I can replace it again easily if I ever need to.

In my case, bad logic board caps caused the normal Mac sounds to not work (startup chime, beeps, etc.) and bad TV sound board caps caused the TV sound to not work.

 

[eraser]

When my Mac TV sound stopped working a few years ago it was indeed because of bad caps.  I think that with the Mac TVs sound is the first clue that something is wrong.

And yes, the TV board is really packed with caps.

 

[MinerAl]

Doug - the only reason I was addressing Uniserver was because he ended up with my MacTV. Thanks for the info! I knew someone had found replacement ones. I just didn't remeber who.