Horizontal green lines

**petestrash** · 19-02-2008, 03:07 PM

Yep, your right.

Lack of sleep here...

Peter.

**Skolink** · 19-02-2008, 08:39 PM

By "video decoder" I'm using the terminology in the SAA7114H datasheet which is confusing. It is not decoding from a digital format but 'decoding' the transmitted analog signal to video + sound (and doing the switching and filtering as you say).
Anyways, since the lines look to me a bit like an intermittent noise or interference fault, I might first try replacing the caps around the SAA7114H, since I don't have a spare IC.
Darren do you mean to keep referring to the CS22, since that is the digital video decoder? That isn't the problem since the .ty files played back on the PC *still have the lines*, so it is in the recording. I assume you mean the CXD1922Q?

**petestrash** · 19-02-2008, 11:09 PM

A Little confused

In post 6 you said the lines were still there on playback on the PC, but the last post you said the lines were gone.

Peter

**Darren King** · 20-02-2008, 07:39 AM

Originally Posted by Skolink

Darren do you mean to keep referring to the CS22, since that is the digital video decoder? That isn't the problem since the .ty files played back on the PC fine. I assume you mean the CXD1922Q?

Yes, sorry. I do mean the Sony CXD1922Q. Like Peter it is lack of sleep (and not actually looking at a TiVo motherboard as it is a bit hard while working away remote from my desk).

Also like Peter asks can you clarify that you are NOT seeing the green lines when playing TY files on the computer?

**Skolink** · 20-02-2008, 07:44 AM

Originally Posted by petestrash

A Little confused

In post 6 you said the lines were still there on playback on the PC, but the last post you said the lines were gone.

Peter

Too tired - was almost midnight. I've fixed the post. Sorry for the confusion.

**Skolink** · 07-04-2009, 09:13 AM

Replacing the SAA7114H IC did not fix this problem unfortunately.

I finally got around to ordering some SAA7114H ICs from Digikey to fix 3 TiVos I have. The intermittent horizontal green lines are still there after replacing the SAA7114H chip. It could actually be something to do with the tuner input, so I will test with the AV inputs (I should have done that first).

The other two TiVo have a "no video input" problem. I replaced the SAA7114H on one of them but it did not resolve the issue. I will try replacing the IC on the third TiVo anyway.

**Darren King** · 07-04-2009, 10:38 AM

Originally Posted by Skolink

The other two TiVo have a "no video input" problem. I replaced the SAA7114H on one of them but it did not resolve the issue. I will try replacing the IC on the third TiVo anyway.

If either of these have a kernel log along the lines of "Could not CXD Boot" then your problem will most likely be the Sony MPEG encoder, or maybe the two VRAM chips hanging off this MPEG chip.

**Skolink** · 14-04-2009, 09:05 PM

Well whats weird is that about a day after I replaced the SAA7114H and discovered the green lines were still there, they dissappeared. A week later and they're still gone. What is stranger though is a new problem appeared. During playback or live TV there is an occassional flicker of an image at the bottom of the screen. I looks like part of the image overlaid, covering about the bottom 10% of the screen, and happens about once every 30 seconds. It doesn't happen in frame-by-frame playback. The flicker is not present when the .ty files are played on the PC. The flicker can be seen on both composite output and UHF output.
This indicates the problem is in the playback / digital-analog section of the TiVo.
Anyone seen this symptom before?

**Skolink** · 25-09-2009, 02:51 PM

Yesterday I tried changing the horizontal resolution on our main TiVo to 720 (yes after owning it for 4 years), and what do know but an intermittent flicker appeared at the bottom of the screen, just like on the 'faulty' TiVo. It even has a heatsink on the MPEG decoder.
I checked on the faulty TiVo and sure enough the horizontal resolution was set to 720 (I don't ever recall changing it). I set it to 544 and now there is no flicker!
All fixed finally
I'm surprised no-one mentioned that the flicker is a symptom of the horizontal resolution being set to 720.

**petestrash** · 25-09-2009, 09:46 PM

The green flicker is caused by the chip working harder than it is currently able to. These chips ability appears to degrade over time.

How were we to know you were running in 720 mode? all you originally said was that you had just set up a TiVo, which usually mean 544.

Anyway with the heatsink on and running in 544 it should give you some time before further degradation.

Peter.