decoder error on Toshiba DVD player?

Don't ignore the possibility of power supply related issues.Look to see if any power supply capacitors - mostly on the secondary side of the SMPS transformer - may have puffed up (vented) tops. This is pretty common the past few years.

Mark Z.

So you say this error manifests in the players own self generated video also?

yes, exactly

J^n

Hi Mark good point - and I've encountered that problem on PC motherboards and routers ... but I can see no evidence of cap. failure here.

I've also checked the composite output and that seems to be exhibiting the same symptom.

J^n

Ouch! I'd go for the SMPS like others might suggest. Don't know about the scale of the Zoran chip set but others since at least 2005 have employed a SoC stratagy or System On a Chip. Usually one large SMD with maybe 200 pins. Hell it may even have been Zoran that I have seen in some cheapy players. I doubt manys ability to dive into a SoC and t-shoot it let alone find and replace.

Or just caps that were minimally specified reducing in capacity.

Sylvia.

Hi again I've managed to get hold of the schematic and from a cursory examination the PSU output seems OK. The same outputs from the Zoran chip are used for RGB and for composite, so it looks like the problem is there, or upstream of there. The Zoran chip is a ZR36732, and there's a 16M ROM and a 64M SDRAM attached.

It wasn't a terribly expensive player and it's done good service - I just don't want to chuck it if there's an 'easy' (heh) fix...

Cheers J^n

Did you look at the PSU supply lines with a 'scope or just a DMM? A high ESR can cause a large high frequency ripple on the DC line(s) which won't be apparent using a voltmeter...

Mark Z.

You are sure it's not crosstalk from an insufficent screened SCART lead connected to the TV with an active return tuner output?

Well I hate to see you give up on it. If I had done that I might have never learned. In order to inspect the PSU properly you are going to have to do more than just eyeball it and some voltages on a DVM. You need to check that the voltages are within the rated tolerance and are producing cleanly withough ripple or spikes under load. Once you're certain your getting clean power from the PSU it might be time to chuck it unless you can get replacement boards and while at it replace the optics sled. Probably end up with enough spent to buy something new though unless you're hell-bent on the repair and learning something.

Yes, I appreciate this - my previous report was just 20mins spent in the shed on a Sunday evening... I have a good 'scope and will have another look later in the week.

Yeah, quite - getting the service manual cost ~$10 (I'm in the UK) and I'm only in the market for a sub-$100 replacement at the moment. Which is another reason for tinkering a bit more.

I might also try to have a look at the SDRAM signals, although my my test equipment I doubt I'll see much unless it's pretty gross. And it's probably worth having a look at the actual video output from the Zoran - that might give men an indication of a fault elsewhere.

Thanks again J^n

Yeah ok nothing wrong with tinkering. The SDRAM is no doubt onboard the Zoran SoC. Read up if you haven't already on MPEG2 compression and you'll better understand what goes on, P,B,I frames. quantized matrixes and codings. It's fascinating stuff.

FWIW the SDRAM is separate to the Zoran. I used to work on UK Digital Set- top boxes so I'm pretty familiar with MPEG ;-)

Cheers J^n

Hi All FYI, I took the main board off and wafted a Heat Gun around the parts which I regarded as suspect - mainly the Zoran chip, RAM and Flash. Put it all back together and ... whaddya know? It's been working fine now, for a week or so. Only had light use, and of course it might go wrong at any time, but I'm pleased for now.

I dunno if I reflowed a dodgy solder joint, or dried off something, or blew a spec of something away ... but I'm happy to mark this one down as a win. Thanks for your previous thoughts on the matter.

Cheers J^n

LOL been there, done that as they say. But I've had more re-runs than not when a "I don't know what I did" repair left the shop with just a basic bench fee.