[jdholman]

Hello:

I've got a Tivo Series 3 HD with a bad power supply which makes a "ticking" sound when plugged in. I replaced the capacitors listed in this guide:
http://www.tivocommunity.com/tivo-vb/showthread.php?t=505873

After doing this, it still ticks and the Tivo doesn't power up.

Any thoughts on what other components I might be able to replace before I need to just replace the entire power supply?

Thanks,

Jim

 

[unitron]

Hello:

I've got a Tivo Series 3 HD with a bad power supply which makes a "ticking" sound when plugged in. I replaced the capacitors listed in this guide:
http://www.tivocommunity.com/tivo-vb/showthread.php?t=505873

After doing this, it still ticks and the Tivo doesn't power up.

Any thoughts on what other components I might be able to replace before I need to just replace the entire power supply?

Thanks,

Jim

The ticking may indicate the power supply protection circuitry detecting an overload somewhere and shutting down momentarily, lather, rinse, repeat.

Or it may be something on the power supply itself.

Double check your soldering to make sure you didn't "bridge" anything.

Double check that you got the polarity on the capacitors correct.

Then try it with nothing connected but the power cord (no Ethernet, no USB, no HDMI or analog audo or video out, no cable or antenna in), no cable cards installed, and the hard drive disconnected.

 

[jdholman]

Thanks Unitron. Caps look polarized correctly. Soldering isn't the cleanest, but no bridging that I can see.

Since it "ticked" before I replaced the caps and still "ticks" after replacing the caps, I'm thinking that there is a good chance that what I replaced wasn't what was broken.

Any other user-replaceable parts I can swap out or testing I can do with a multimeter?

Jim

 

[unitron]

Thanks Unitron. Caps look polarized correctly. Soldering isn't the cleanest, but no bridging that I can see.

Since it "ticked" before I replaced the caps and still "ticks" after replacing the caps, I'm thinking that there is a good chance that what I replaced wasn't what was broken.

Any other user-replaceable parts I can swap out or testing I can do with a multimeter?

Jim

Did you do the "nothing connected but the power cord" test I recommended, and does it still tick?

 

[jdholman]

Thanks for the reply, Unitron.

I did check this and the power supply ticks whether it is connected tot he Tivo main board and drives or not. I tried this out before I hooked it up after replacing the caps and I just re-confirmed it right now.

Thanks,

Jim

 

[unitron]

Thanks for the reply, Unitron.

I did check this and the power supply ticks whether it is connected tot he Tivo main board and drives or not. I tried this out before I hooked it up after replacing the caps and I just re-confirmed it right now.

Thanks,

Jim

Switching power supplies, which is the type that TiVos use, should never be operated without a load connected.

And if it ticks without any load connected at all, that doesn't necessarily mean anything.

That said, it looks like you're going to need to get hold of another power supply, even one that's failing but hasn't finished failing, to see if your problem is the power supply or the motherboard.

However, first try it for just a few seconds with the hard drive hooked up but not the motherboard.

As soon as you do or do not get ticking, unplug it. Report back.

 

[jdholman]

What's the easiest way to get a power supply for testing? I see some on eBay for $50 with free shipping. I suppose I could buy one and use it for testing to fine out what is broken and sell it later if I don't need it.

I'd be afraid of buying a broken Tivo not knowing if the PS is good or bad.

What do you recommend?

 

[unitron]

What's the easiest way to get a power supply for testing? I see some on eBay for $50 with free shipping. I suppose I could buy one and use it for testing to fine out what is broken and sell it later if I don't need it.

I'd be afraid of buying a broken Tivo not knowing if the PS is good or bad.

What do you recommend?

There aren't any 652s or 658s (power supplies are interchangeable) offered on the Atlanta Craigslist right now, but I might be able to find you a re-sell-able one (i.e., still subscribed) elsewhere that you could borrow the power supply out of for test purposes, and that you could use to test your own power supply.

 

[jdholman]

Thanks. Let me know what you can find.

My thoughts are that if I can buy a used PS for $50 to test out my main board, I can probably resell it for $50 and only net the shipping and eBay fees, probable $12. If the main board is fine and everything works with the used PS, my options are to either keep the $50 PS with old caps, continue to try to fix mine with the replaced caps, or buy a refurb PS with new caps.

Not sure. Where do you think?

 

[unitron]

Thanks. Let me know what you can find.

My thoughts are that if I can buy a used PS for $50 to test out my main board, I can probably resell it for $50 and only net the shipping and eBay fees, probable $12. If the main board is fine and everything works with the used PS, my options are to either keep the $50 PS with old caps, continue to try to fix mine with the replaced caps, or buy a refurb PS with new caps.

Not sure. Where do you think?

This

http://atlanta.craigslist.org/nat/ele/5539614975.html

will get you a working power supply and a 1TB drive (with several years on it) for $15

 

[jdholman]

So I received the PS I had already ordered, connected it to the chassis and power leads to the board and drives, crossed my fingers and... it worked.

So now I have a $60 power supply replacement that works and a broken one that I tried to fix with $16 worth of Digi-Key caps.

I'd still like to get the bad one working but I'm not sure it's worth the time at this point. What do you think Unitron?

 

[neurocutie]

So I received the PS I had already ordered, connected it to the chassis and power leads to the board and drives, crossed my fingers and... it worked.

So now I have a $60 power supply replacement that works and a broken one that I tried to fix with $16 worth of Digi-Key caps.

I'd still like to get the bad one working but I'm not sure it's worth the time at this point. What do you think Unitron?

suggestions to look at:
1) all semiconductors (transistors, thyristors, etc). If there is a crowbar circuit, the SCR could easily cause a ticking sound.
2) transformer windings. Possible short in the winding could be a problem.
3) power supplies are generally fairly easy to suss since there is a well-defined input and output. Start at the input and trace onwards. A good milestone point is any "high voltage" DC intermediate, like the output of the primary rectifiers. Those btw would be good targets for checking -- is the just-rectified DC output look right (in waveform and in voltage level)?
4) since you just replaced the caps, checking the resistance across each cap to make sure you didn't introduce a short by mistake. Pay attention to which way you apply your ohmmeter (remember it is sourcing DC to make the measurement and has a polarity +/- (which often is opposite what you would guess)).

 

[jdholman]

Thanks Neuro. I'll check it out.

Jim

 

[Abextra]

I just had a power supply die on one of my HD boxes. It was a supply that had required a cap change 2 years ago and it worked well until this week. The big transformer T100 was producing a "ticking sound" and based on the fact that it sounded like a consistently timed electrical discharge "snap" in the Hi Pot transformer. I just swapped the supply out with another I had on hand because the transformer would be hard to find and time is money. Regards Rob