looking for schematic whites 2/db series 2

[la Taupe]

hi from France

I have this Whites coinmaster 2/DB series 2
as new condition , not the smallest scratch
but it does'nt sound ; no beep .

what to check ?
PC card shows 505 - 0121 number .
please send schematic

[Skippy]

You will need to replace every electrolytic capacitor. If you think it is a power-supply decoupling one, you can use a larger capacitance, and obviously a larger voltage-rating, if you see fit. If it is not power-supply, keep the same capacitance value, though V rating can obviously be higher.
Other problems:
Coil cable issues, like the solder joints on the connector, broken wires.
The PP3 battery connectors are prone to failure with use.

[Carl-NC]

Most likely this is the schematic for your model. Skippy is right, start with battery connector, see if the battery voltage gets to the PCB. Then check the power supply, TX, etc.

2500_2900_1Db_2Db_2000D_3000Ds3.pdf

[la Taupe]

I didnt noticed that before but battery holder - located in cover - shows evidence of corrosion .
certainly detector stored long time with battery inside !
fortunately no corrosion on PC board .
tomorrow I will replace battery connector .

[la Taupe]

many thanks for schematics Mr Carl .

[kt315]

You will need to replace every electrolytic capacitor. If you think it is a power-supply decoupling one, you can use a larger capacitance, and obviously a larger voltage-rating, if you see fit. If it is not power-supply, keep the same capacitance value, though V rating can obviously be higher.
Other problems:
Coil cable issues, like the solder joints on the connector, broken wires.
The PP3 battery connectors are prone to failure with use.

electrolytic capacitors are checked, on ESR, by ESR meter, be not desoldered from the board. checking right in pcb.
no need to replace all electrolytics.

[Carl-NC]

Yes, I would only replace electrolytics once the circuit is running and it's apparent they need replacing. I have a lot of old detectors from the 1960s, 70s, and 80s that all work just fine with original components.

[kt315]

first of all he must to delete a speaker and phone connector. to learn them on corrosion and state. to check the speaker on Ohms and condition.
no need the circuit here. circuit does give nothing.

[la Taupe]

hello

speaker is OK
new battery clip solded
it sounds more less 15 seconds and then cuts .
the same 10 attempts.

two things I noticed

small capacitor not sold " factory " way
and so for that pot !!

obviously it had a life before death !!!

[ivconic]

Curiosity sake, can you take a photo of its coil and what's engraved on the "ears" on it (usually left one)?
Usually it is the type of coil engraved there.

[la Taupe]

6B engraved
is that correct ?

[kt315]

yup

[ivconic]

Yes thank you!
So 6B.
I have 4B and 5B!

[Skippy]

How are you getting on with this?
I see the manufacture date is 1981, based on component markings, so it's 44 years old. (That's why I said replace the electrolytics - don't mess about testing the existing ones, just replace them, there aren't that many, and most are PSU decoupling )
How are the power supply voltages? I calculate the Vcc and Vp regulated supply as 6.2V.

Check the continuity ( at DC ) of the coil windings, and flex the coil cable, to check for any intermittent cable breaks.

[la Taupe]

hi
unfortunately some health issues ...
so no time for electronics and it will be the same next week .

but I dont give up

many thanks for your helpful advices