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

Gusandy

New Member
Hi all - I'll apologize ahead for being a newcomer. I have this "goodwill special" system that looks to be in good shape with the dvd player missing. Apparently this piece of the component system controls the on/off signal to the main amplifier built into the sub (I'll included a few pics). Of course it has a proprietary "system cable" that alot of manuf incorporate into their systems now. This plugs into the dvd player into the sub. I need to know if I can bypass the need for having the dvd player and remote allowing use of this sub and speakers as a standalone system connected to a receiver. The sub has an input L and R rca but this does not activate / turn on the sub. The sub is an active sub. I've taken it apart thinking I could get the datasheet on the IC amp chip but do not know how to read / understand the pinout. I'm good with solder and know basics for a mulimeter. I just need someone to locate the circuits / pins to bypass if any "standby" mode exists (see pics). I've performed a similiar fix on a sub for a bose 3-2-1 system (big dissapointment there:( ). It's rediculous what bose charges for their sub-par systems but thats just my opinion. That's another topic. I appreciate anyone giving me any advice on this. It has some pretty large drivers and the system has good reviews. Could this be as simple as a jumper at the system cable connector?? Thanks again.

Amp chip:
IC TA2022 (The amp board has 2 of these)

See pics belowBackplane board&amp.jpgBackplane&amp-B.jpgBackplane board system cbl connector.jpgAmp connector board-A.jpgAmp connector board-B.jpgBackplane board flipside-A.jpgBackplane board flipside-B.jpgBackplane board-A.jpgBackplane board-B.jpgAmp IC.jpgTransformer.jpg
 
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rjenkinsgb

Well-Known Member
Most Helpful Member
By some miracle the D connector for the interlink has the pins labelled!

See what voltages you get on the VCC, SW and 4066_SW pins, relative to the GND pins?

If SW is high (anything from 2 to 5 V), try connecting it to GND with a 470 Ohm resistor.
If it's near 0V and the VCC pins have 5V, try connecting it to 5V via a 470 ohm resistor.

One or the other will hopefully switch power on?
 

Gusandy

New Member
Hi thanks for the quick response :) Wasn't exactly sure but I believe the D connector referred to is the 3rd pic from the top?
I'll include a pic but wasn't exactly sure what pins you were referring to? I apologize.

" See what voltages you get on the VCC, SW and 4066_SW pins, relative to the GND pins?"

See pic for my shotgun approach. I hope that answered the questions?20200922_110015.jpg
 
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rjenkinsgb

Well-Known Member
Most Helpful Member
OK. I missed the "5V" and "P_CON" pins - do you get anything on those to ground?

(I was thinking aloud there; the two rows of staggered pins is very similar to a typical D connector, though that is not actually one.)

If there is no power on any pin, presumably the original head unit has a separate power supply & the unit you have probably needs 5V applying to an input pin to enable it.
 

Gusandy

New Member
Thanks again...your awesome for helping:cool: I deleted and re-uploaded the latest values in that last pic. Still have to get me that resitor but wanted to clarify everything first. I also included a GND pin i used to get those values at the bottom of that pic. This unit does have a transformer providing about 25vac,11vac, and 15vac on three legs. I apologize again for being a lamen with this stuff. I know enough to shock myself;(
EDIT:
Retested dc voltage at the transformer to connector ground and getting 1.5 at each of the trans 5pin connection. Getting 3.1vdc at the smaller 3pin trans connector.
 
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Gusandy

New Member
Thats what i thought at first but wasnt getting any readings. I dont know which grounds i should be referencing? This is what im working with (wife frowns...)20200922_100013.jpg
Checked and changed values on that paper again.Thanks for taking a look.
 
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rjenkinsgb

Well-Known Member
Most Helpful Member
Hopefully all the grounds are electrically connected at some point, even if via some resistance.

I'd try connecting a 5V supply (or 4.5V from some AA cells) via a 470 Ohm or 1K resistor to the P_CON terminal?
(With negative to ground).

I cannot see a relay on the power board so I'm guessing it uses electronic switching. That may switch the main power on.
 

Gusandy

New Member
Hi thx. Okay i found 3 200 ohm resistors and wired them end to end getting 600 ohms. I tested the pins and keep getting varied readings.
P_con to vgnd ranges from 1.5v to 5v without resistors. Reads 0v after connecting resistors.
+5pin to vgnd ranges from 5v to 9.5v. This declines to .482 after connecting this pin to p_con pin with 5v pin. Also the 5v pin to vgnd reads 10.1v with resistor still connected to pcon and +5 pin. I've connected my phone to the input with a 3.5mm to rca cbl and played music-no success. There is no noise or reaction from sub.
However, the fan comes on when connecting pcon to vcc_gnd but no sound still.
Im lost...
Thx for any more help20200924_102031.jpg
 

Gusandy

New Member
Not sure if signicant or not but the Dconnector (for system cbl) has 4 pin holes the are larger diameter than the rest...
Both Vcc_gnd holes, vcc, and +5 at the other end.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
OK, progress!

If P_CON shows 0V when connected to vcc_gnd via the resistor, it will be OK to just use a wire link for that connection (or an on/off switch).

With that connected, what's the voltage on the 4066_switch pin? You could try connecting that to either ground or a pin that has 5V on it, again via the resistors.

(The resistors reduce the chance of damaging anything while testing connections, by avoiding a direct short that could blow something).

It sounds like there may be two totally separate, floating, 5V supplies, each with its own ground - or I'm misinterpreting some figures...
 

Gusandy

New Member
If P_CON shows 0V when connected to vcc_gnd via the resistor, it will be OK to just use a wire link for that connection (or an on/off switch).
Did you mean when connected to vgnd? This was the 0v reading i was referring to above. The vcc_gnd pins do not alarm when performing continuity test to the connector body. The vgnd pin does. I dont know what these vcc_gnd pins ground to but not a typical ground.
 

Gusandy

New Member
4066_sw reads 0 when probes touched to connector case/vgnd. Tested the +5v pin to vgnd looking for a 5v source but now reads 15 at first, dropped eventually to about 13.4v. Vcc pin to vgnd is now at 28 to 29v.
Connecting 4066_sw pin via resistors to +5v pin results in about 13.4v when testing 4066_sw to vgnd.
Connecting the -vcc (having 5.7v) pin to 4066_sw via resistors results in 7.5v when probed to vgnd.
 
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rjenkinsgb

Well-Known Member
Most Helpful Member
P_CON to whichever ground causes the fan to switch on.

I'd try linking two ground pins that are not already showing continuity, to see if you can get the various 5V lines to read the same voltage.
At the moment it appears there are two totally separate power systems, which is confusing things.
 

Gusandy

New Member
P_CON to whichever ground causes the fan to switch on.
Yes, grounded to vgnd via a jumper wire. Fan runs but seems to be faulty and required a "spin" to get going this time, but stays running afterward. I will address that after I get sound :)
I will attempt to get a better pic and edit some connections using the pic. Would you know a better solution so I we can follow one another easier?

Also, to clarify, when "testing" voltages, is it testing these pins to ground you require (which I have been doing) or testing across the jumpers/resistors at the connector? Or both? Sorry...
 

rjenkinsgb

Well-Known Member
Most Helpful Member
Testing to ground; the confusing thing is that there appear to be two "grounds" that hove no connection with each other, hence the suggestion to link them & simplify it a bit.
 

Gusandy

New Member
Here is the latest. The jumper in red is connected via resistors. Something interesting happened when testing the sp_ry pin - clicking was heard. It was done when using my probes.Ground jumpers connected.png
 

Gusandy

New Member
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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