Recovery off an RadioShack Answering Machine 43-3825

[Giroot]

Hello,
I was wondering if it was possible to recover deleted voice messages off this kind of answering machine.

From the pictures attached, I cannot see any memory chips inside that would store the messages, although I have not looked underneath the pcbs yet.

Bottom of the answering machine.

I can see one microcontroller (marked in red)
Markings:
EM78P153SP
0347N DP3BC4
Datasheet:http://www.emc.com.tw/chs/database/Data_Sheet/8BIT/EM78P153S.pdf

The other chip (marked in blue)
Markings:
PC-17T1
0347
DD
Datasheet:https://www.digchip.com/datasheets/download_datasheet.php?id=745872&part-number=PC-17T1

If anyone can help identify the other parts on the PCB that would be much appreciated!

Attachments

top part of the answering machine. most likely for the buttons on the machine, and the lcd screen

[fzabkar]

If there is an FCC ID on the label (eg AAO43-3825), then there may be a circuit diagram at the FCC's database. This would be unlikely, though.

Otherwise, RadioShack used to provide parts lists at its support site. You might like to try the Wayback Machine.

http://support.radioshack.com

BTW, PC-17T1 is an optocoupler. It would isolate the AC ringer (90VAC) from the electronics.

Last edited by fzabkar on March 27th, 2018, 23:00, edited 1 time in total.

[Giroot]

Alright. I've looked underneath the bottom pcb, and it's looks a lot more promising.

Chip to the side markings are
CW417403-6
CJ 0323

Also, does anyone have a datasheet for the DSP chip?
DSP
DL16328PAC11AQC
2001 DSPG
TME693B0002A 0344
SIC0708Y

Thanks,

EDIT: @fzabkar, Thanks for the info!

Attachments

[fzabkar]

I suspect that the DL16328PAC11AQC chip was made by the DSP Group:

https://www.dspg.com/

That would account for the "2001 DSPG" copyright marking ... and the logo.



I'm wondering whether the CW chip might be a RAM, and whether there is any flash memory at all. The 9V battery may be the backup for more than just the clock.

[fzabkar]

The links are dead, but try the Wayback Machine.

Owner's Manual for Radio Shack Answering machine TAD-3825, cat# 43-3825, TAD-3825:
http://support.radioshack.com/support_p ... /72809.pdf

Parts List:
http://support.radioshack.com/support_p ... /72743.htm

[HaQue]

CW chip: The only chip manufacturer I could find that logo comes close is Calibre Inc. They were bought by Zilog in 2000. They mainly did wireless stuff, IR, Bluetooth etc. Possible as on one of the pics there is a sticker "remote code". But I don't know if it is a red herring, as you used to use a code to operate answering machine from a remote telephone back then.

calibre.png (2.16 KiB) Viewed 9851 times

Possible the chip does DTMF tones or is an ADC. here are 2 manuals for similar (not the same) products. I couldn't see a whole lot extra info able to be gleaned from them

43-3829

43-3829.pdf

(927.06 KiB) Downloaded 430 times

43-3888

43-3888.pdf

(126.3 KiB) Downloaded 457 times

you may be able to get some info by searching for schematics/photos circa the date of your unit. match up similar looking circuits with chip functions.

could you post pic of outside of unit and model sticker

[fzabkar]

If AC power fails or you unplug the system, one 9V alkaline battery (not supplied) is needed to save any recorded messages and the settings for the day and time.

[HaQue]

Yes,
I think the absence of flash memory, unless it is in the DSP chip, and that statement.. not a lot of hope

[fzabkar]

@Giroot, if you disconnect the AC adapter and install the 9V battery, can you measure a supply voltage at the CW chip?

could you post pic of outside of unit and model sticker

https://www.ebay.com.au/itm/Radio-Shack ... _606wt_264

http://i.ebayimg.com/images/g/55IAAOSwo ... -l1600.jpg
http://i.ebayimg.com/images/g/q88AAOSwt ... -l1600.jpg
http://i.ebayimg.com/images/g/Q8wAAOSwa ... -l1600.jpg
http://i.ebayimg.com/images/g/cagAAOSw2 ... -l1600.jpg
http://i.ebayimg.com/images/g/RboAAOSwa ... -l1600.jpg
http://i.ebayimg.com/images/g/toQAAOSwt ... -l1600.jpg
http://i.ebayimg.com/images/g/O-oAAOSw2 ... -l1600.jpg

[Giroot]

Thanks for your help everyone!

could you post pic of outside of unit and model sticker

https://www.ebay.com.au/itm/Radio-Shack ... _606wt_264

http://i.ebayimg.com/images/g/55IAAOSwo ... -l1600.jpg
http://i.ebayimg.com/images/g/q88AAOSwt ... -l1600.jpg
http://i.ebayimg.com/images/g/Q8wAAOSwa ... -l1600.jpg
http://i.ebayimg.com/images/g/cagAAOSw2 ... -l1600.jpg
http://i.ebayimg.com/images/g/RboAAOSwa ... -l1600.jpg
http://i.ebayimg.com/images/g/toQAAOSwt ... -l1600.jpg
http://i.ebayimg.com/images/g/O-oAAOSw2 ... -l1600.jpg

Yes, that's the correct model

[Giroot]

If AC power fails or you unplug the system, one 9V alkaline battery (not supplied) is needed to save any recorded messages and the settings for the day and time.

Yes,
I think the absence of flash memory, unless it is in the DSP chip, and that statement.. not a lot of hope

Final Update: Decided to not continue forward with this one, due to these statements. The lack of a memory chip makes recovery too difficult.

Thanks for the help everyone.