Toshibs DVD Video Suddenly Dark

[bountyhunter]

I have a Toshiba VCR/DVD Player combo. Suddenly for no reason, the DVD player lost all video output but still has audio. Video out is fine playing tape, no video on DVD. Tried disc cleaner and multiple DVDs. Don't have a schematic. Anything obvious on these before I punt it?

 

[Nigel Goodwin]

Perhaps you might try posting the model number?.

A good possibility though is high-ESR electrolytics in the PSU.

 

[bountyhunter]

The model is SD-V392SUA.

I doubt it's the power supply because the VCR side works perfectly both in record and playback mode. I would assume they use a common power supply. I suppose it's possible the DV side has rails used only on that side.

I was thinking something in the digital video path which is probably some ASIC designed for Toshiba that isn't available and would probably cost $40 if it was.

 

[Nigel Goodwin]

PSU is always first thing to check - no sign of a manual for that model number though, presumably you aren't in Europe, but you don't have your location filled in.

 

[bountyhunter]

United States. I have no idea where to get a schematic either.

 

[killivolt]

PSU is always first thing to check - no sign of a manual for that model number though, presumably you aren't in Europe, but you don't have your location filled in.

Nigel, Could a weak laser be responsible for no video

Could it still have audio maybe ? If the DVD is not correctly formatted, if it's been ripped let's say it may not read the video but may read the audio. or...

If he's got video on the VHS side is he using the same Video out ? of NTSC or PAL. If the source is different to separate video's out (Like Nigel Said Power supply issue's are a possibility as it will use different circuits for each)

Not to mention, You could have sound and no video if your using RGB Or Pb,Pr, Loss of sink pulse means you could read but not produce video most likely this loss of video indication is visible from the on screen display as no signal.

But, if it's a sink issue, it may not produce a reliable signal and the on screen display will not show the "no signal" in the on screen display which means something is there but not reproducible.

kv

 

[Nigel Goodwin]

Nigel, Could a weak laser be responsible for no video

I'm presuming he doesn't get the on-screen graphics from the DVD secrtion, so it couldn't be. It couldn't be anyway, because it either reads and works OK, struggles reading and freezes and blocks a lot, or doesn't read the disc at all.

 

[bountyhunter]

It's trying to play factory CDs, not ones I recorded. No screen images at all, just black. Outputs are the three regular outputs (L-R audio and video). I would guess it's the DSP chip or somthing in the video path after it.

 

[killivolt]

It's trying to play factory CDs, not ones I recorded. No screen images at all, just black. Outputs are the three regular outputs (L-R audio and video). I would guess it's the DSP chip or somthing in the video path after it.

Remove the cover and in the power section take a hair dryer or heatgun.

Be very careful and heat around the secondary side of the power supply mostly in and around capacitors. Poor solder joints also will cause video to appear then disappear when heating then cooling. This is due to expansion of the solder on the connection.

Take care using a heat gun around plastics a little goes along way. If it's anywhere near your loading deck don't do it. Little gears and parts will be destroyed easily.

If you have some freeze spray then do the opposite. The capacitors will reflect changes in capacitance either in the heating or the cooling as well.

 

[sheldonstv]

here is the full service manual for that model...........

 

[bountyhunter]

here is the full service manual for that model...........

Thanks, I couldn't find one.

ADD:

WOW! Amazing how complicated that sucker is. hard to beieve they could sell them for $150.

 

[sheldonstv]

well hopefully the manual will help you get it going-i have to repair these things day in day out so im pretty well used to it

 

[bountyhunter]

well hopefully the manual will help you get it going-i have to repair these things day in day out so im pretty well used to it

Can you still get replacement parts like the DSP chip?

 

[sheldonstv]

i believe so yes but i havent had to replace one yet in this model.....if needed one of my parts suppliers may be able to get one special order if it is needed-how far have you got with it?

 

[unclejed613]

did you mistakenly switch to some video mode that's not supported by the monitor? i see it a lot, or maybe (i know Pioneers do this) switch the video to one of the outputs you're not connected to? i.e. if your monitor is connected to the component jacks, did the output get switched to HDMI or composite? some models and brands supply video to all outputs simultaneously, some do not.

 

[bountyhunter]

i believe so yes but i havent had to replace one yet in this model.....if needed one of my parts suppliers may be able to get one special order if it is needed-how far have you got with it?

Honestly, I haven't torn into it much. I took the top off and wiggled all the ribbon connectors in thir sockets and wiggled the wires but no reaction. It's an old unit that does not have a dig tuner on board (have to use a converter box) so I will probably just use it as a backup VCR recording device for garbage programs like Jay Leno... I was using the DVD to dub material onto a DVD recorder but I have another machine to use if I have to do that.

I reviewed the schematics, and didn't see anything obvious or easy. I'm not motivated to put any time or money into it, and I don't have the desoldering equipment to change large SM IC's like the DSP chip anymore..

 

[bountyhunter]

did you mistakenly switch to some video mode that's not supported by the monitor? i see it a lot, or maybe (i know Pioneers do this) switch the video to one of the outputs you're not connected to? i.e. if your monitor is connected to the component jacks, did the output get switched to HDMI or composite? some models and brands supply video to all outputs simultaneously, some do not.

No, it's hooked to the TV and I never switched anything... it just went dark on the video from the DVD side. The video from the VCR side of the unit is still fine,so I can still use it for that.

Really odd that the DVD player pooped out before the VCR, I have never heard of that happening.....

 

[unclejed613]

the video processor for the DVD is on a different board, usually either the DVD driver board, or the DVD signals on newer machines tends to go straight to the HDMI board and is run through some DACs to make the analog outputs. it could be as simple as the analog video amp being bad or the HDMI chip, or other video processor chip. if you're getting audio there's nothing wrong with the DVD mech or optics, since the video and audio reside in the same data stream from the disk surface. if it's a black screen but you have sync, then it's most likely somewhere other than the analog chip that buffers the signals. have you tried checking other video outputs for signal (if any)? in 480p or 480i mode, the green jack will give a visible (in black and white, and a double picture in 480p) on a composite monitor. if you have signal there, chances are it's the combiner for the composite signal, or an analog switch in the composite signal chain (like the switch that switches between VCR and DVD video, which it could be). a lot of these chips are surface mount dips that have very small pin pitches, or worse, little 24 pin BGA chips with the solder blobs UNDER the chip. these aren't simple to replace anymore (even with SMT skills, the BGA chips are pretty much a no-go, since you have to place the chip "blind", and if it works it works, but if it doesn't work you're done...)

 

[bountyhunter]

the video processor for the DVD is on a different board, usually either the DVD driver board, or the DVD signals on newer machines tends to go straight to the HDMI board and is run through some DACs to make the analog outputs. it could be as simple as the analog video amp being bad or the HDMI chip, or other video processor chip. if you're getting audio there's nothing wrong with the DVD mech or optics, since the video and audio reside in the same data stream from the disk surface. if it's a black screen but you have sync, then it's most likely somewhere other than the analog chip that buffers the signals. have you tried checking other video outputs for signal (if any)? in 480p or 480i mode, the green jack will give a visible (in black and white, and a double picture in 480p) on a composite monitor. if you have signal there, chances are it's the combiner for the composite signal, or an analog switch in the composite signal chain (like the switch that switches between VCR and DVD video, which it could be). a lot of these chips are surface mount dips that have very small pin pitches, or worse, little 24 pin BGA chips with the solder blobs UNDER the chip. these aren't simple to replace anymore (even with SMT skills, the BGA chips are pretty much a no-go, since you have to place the chip "blind", and if it works it works, but if it doesn't work you're done...)

Interesting.