Sanyo-DWM4500 bypass standby circuit - dvd component system - missing dvd player/remote. IC ta2022

Gusandy said:

I had a few questions - where does one get data sheets / service manual on this unit? Would it be worth the cost? Would that help ppl such as yourself to locate which pins to connect to be able to bypass the unit? Also, if the volume is controlled in the dvd part of this speaker system, how would one "turn up" the volume? Would it be by whatever is plugged into the aux rca input?
And thanks again for all the help

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If the volume is controlled by circuitry in the DVD section, then it looks like you're probably missing far too much of what you need?.

This system isn't separate units, it's one single unit split off into a number of different boxes to give the impression of separates.

A quick google doesn't find any free service manuals, but there's no guarantee of how useful it would be anyway - many modern manuals don't provide any schematics or anything.

EDIT:

I've just been checking the instruction book - you're fooling yourself (and others here) by saying you're 'missing the DVD Player' - when all you've got is the speakers, and you're missing pretty well all the electronics.

Sorry Nigel but I do know enough about it to know this system would work without the dvd player. It has a self contained power unit (active) speakers on not just one but 2 of the speaker components (the sub and the rear speakers). An amp is contained within both. Also, the sub unit even has its own aux input for an external source to be plugged in. Just a matter of finding the circuits (which I don't know enough about them to approach myself). I do admit, this part is beyond my skill level. Looking at the manual reveals a system cable used to turn on the sub unit from standby.

Why would they put all the inputs, outputs, amp, power board in the sub unit if "pretty much all of the electronics" were in the dvd player? Looking at the manual reveals the dvd player as a slim device that uses the sub unit to manage all of the speakers. The pics I posted reveal as such.

It's not my intent to waste anyone's time. The other speakers work without any circuit bypass plugged into the correct outputs on a typical receiver. The rear wireless speaker has an input that plays via my phone. Anyone willing to tackle the sub unit has the pics posted here. If more are needed to take a good look, I can do that. If not, there are 2 good drivers in this sub and with a little modification, can be connected to a cheap small amp board and used accordingly which is plan B. I would hate to forgo the use of the built in inputs/outputs in this sub, but if noone here can help thats fine too. It was worth the try Thanks for the attempt anyway.

You need a schematic - otherwise you're just guessing.

However, as all the controls are on the DVD section, it's probably not as simple as you were hoping.

Any suggestions to acquire the schematic? Again, new to this part of it. I used to take electronics years ago to a gentleman that would acquire the schematics via the manufacturer (snail mail). Antiquated yes....but has worked. Any suggestions to this? Thanks again.

Gusandy said:

Any suggestions to acquire the schematic? Again, new to this part of it. I used to take electronics years ago to a gentleman that would acquire the schematics via the manufacturer (snail mail). Antiquated yes....but has worked. Any suggestions to this? Thanks again.

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I'm no longer in the trade, but in later years it became common practice for service manuals to either not be available at all (even to authorised main dealers), or if they were, to not include schematics.

I too used to get service manuals via 'snail mail', but it was pre-internet, so electronic manuals weren't an option - but even with the paper manuals it was a GOOD many years ago when manufacturers stopped supplying other than their authorised agents. For many years I did quite a few Pioneer repairs, and while I worked at an authorised service agent for many makes, Pioneer wasn't one of them - and one day Pioneer turned round, and wouldn't supply either manuals or spares unless you were an authorised agent.

Pioneer was the first I came across doing that, but since then it's become pretty standard practice with most manufacturers.

Where I worked we WERE a Sanyo authorised agent, but Sanyo pretty well died out in the UK a long time ago, and in any case I no longer have any access to any of the manufacturers we used to be agents for

As google doesn't find any schematics, I suspect they have never been available?, as if they were someone would have posted them on-line long ago.

Thanks for the candor and help I'll fool around with it a bit more....If I "fry" anything no harm done, aside from myself that is Maybe the post here will give someone smarter than myself a good start anyway. Of course if they are that inclined, they probably wont need to search the internet for solutions Take care...

Hello again, I was able to acquire a schematic for this sub! With that being said.....will this help anyone aiding me in getting this off my bench and into proper use? I'd very much appreciate There is the full schematic of the sub below. Thanks again.

Have you got the rest of the schematic?, as I explained before the sub-woofer is missing most of the amplifier and control systems, it's essentially just a power amplifier. Even if you can power it up, there's no way to select inputs or control the volume etc.

Wow, that's a rather complex system!
It turns out that the aux sockets on that unit just link to the multiway connector, audio_l and audio_r

The OUTPUT_xx pins are the inputs to the various channel amps;
OUTPUT_FL and OUTPUT_FR are the inputs to the main channel amps in that unit.

A stereo pot should provide a volume control, with the cw ends to AUDIO_L and AUDIO_R then wipers to those OUTPUT_ connections (and CCW end to AUDIO_GND).

You could try feeding audio in to output_fl / ouput_fr, starting at zero volume, while powering P_CON from 5V to switch the amp on?

rjenkinsgb said:

Wow, that's a rather complex system!
It turns out that the aux sockets on that unit just link to the multiway connector, audio_l and audio_r

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Which is what I said all along - it's NOT a DVD Player, it's the main part of the entire system, that just happens to also contain the DVD player. Essentially the rest are just powered speakers.

Thanks again all, and to keep things moving forward, here is the requested service manual. If you have any suggestions on what it would take to wire this to work....I'm all ears. Complications aside. If it takes a few external components I have laying around then so be it....I'm up for the challenge if you are? If outside of my comfort zone, I can let you know. If you are outside of your comfort zone...likewise However, I do appreciate the help

rjenkinsgb said:

A stereo pot should provide a volume control, with the cw ends to AUDIO_L and AUDIO_R then wipers to those OUTPUT_ connections (and CCW end to AUDIO_GND).

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rjenkinsgb - could you keep it "layman" for me? What is "cw ends?" I've located those pins and can do the necessary splicing and jumping of wires but lost on jargon. Also....."wipers?" I can source a potentiometer.

I hope the manual gives you insight. I'm sure it proves you correct Nigel. After I clarify the above, I'll give you guys a progress pic and any failures / successes. Thanks again

Gusandy said:

Thanks again all, and to keep things moving forward, here is the requested service manual. If you have any suggestions on what it would take to wire this to work....I'm all ears. Complications aside. If it takes a few external components I have laying around then so be it....I'm up for the challenge if you are? If outside of my comfort zone, I can let you know. If you are outside of your comfort zone...likewise However, I do appreciate the help

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What are you wanting to do with the unit? - that makes a HUGE difference to how much circuitry you would need to add.

Gusandy said:

could you keep it "layman" for me? What is "cw ends?" I've located those pins and can do the necessary splicing and jumping of wires but lost on jargon. Also....."wipers?" I can source a potentiometer.

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See this link, specifically the second (red & blue) sketch:

The wiper is the moving part of the pot, usually connected to the middle terminal.
Looking from the "user end" of the pot, the CW and CCW terminals are the ones the wiper is closest to when turned fully clockwise or anticlockwise.

Note that you need a dual-gang pot for the stereo volume control. I'd try a 10K "A" (log taper) one, eg.

Gusandy said:

Why would they put all the inputs, outputs, amp, power board in the sub unit if "pretty much all of the electronics" were in the dvd player?

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because the source switching is either on the main PCB in the DVD unit or is controlled from there. it doesn't look like all of your inputs are routed back through the D connector, so the selector is likely controlled by a serial data line from the main PCB. "Dcont1" and "Dcont2" are likely the serial interface. is there a large chip in the speaker section that would be communicating with that port? that's probably where the input selector and volume control circuits are...