Bump
ee to Bump
or . . . Come in pls
WHASSAMATTAH . . .got yer tail rotor in a bind . . . . and yer caught in a fast earthward spin ?
? ? ? . . . . . hint . . . . . hint . . . . . (Sikorsk
y)
MAGNIFICENT pflux clean up on the board . . . . .
Lets initially do some analytical
LOW ohm testing.
Your YELLOW area has too large of solder blobs built up at Yellow B and Yellow C.
If YELLOW C has accidentally connected to the GROUND PLANE surround, it could simulate a continual activation of that switch, even though it has not been pressed down
IF that switch is being a SPDT type.
Also that condition over rides any other switches action . . . . .first come first served . . .until released.
TEST A . . . . .
Since your RED A-B-C areas have more normal solder joints lets see if we can test them first.
Stabbing ohmmeter probes into RED A and RED B should show an open circuit, then if you click that microswitch button, a short circuit should show with the metering . . . thus, all is well . . so far..
TEST B . . . . .
To now confirm the microswitch type . . . . ohmmeter probes are placed across RED B to RED C, see if it shows a short and then click the switch to see if it changes to an open circuit.
RESULTS . . . . .
If the test of RED A to RED B agrees with the above, all is well with that switch.
If the test between RED B to RED C agrees with the above then we have a
Single Pole Single Throw type of switch configuration.
If the tests of RED B to RED C agree with the above, we have a
Single Pole Double Throw type of switch.
In which case, the RED B connection normally rests on RED C connection, but upon button activation, it swings over to make contact with RED A connection, for the time of activation.
If RED B to RED C connection always remains an open circuit, irregardless of switch activation, we have a SPST switch and the RED / YELLOW C connection is of no relevance on either RED or YELLOW switches..
Sooooooooo the aforementioned YELLOW C solder blob shorting to ground plane would not create a fake switch on condition.
FURTHER TESTING . . . . .
Move back to YELLOW A to YELLOW B with the meter probes and that should be readingas an open circuit. Activate the microswith button and a short should develop for the pressed time period.
Repeating that test with RED A to RED B should give the same results.
One question now is being relevantt to the the C11 block ceramic surface mount unit.
I can see the left side being OK with its connection to the massive ground plane at its connection point.
Then am I correct that the original fine foil trace is good from the 45 deg bend at the top ( within marked in fine GREEN circle) down until it connects to the right half of that cap ?
Then I see your fine cu wire add on to reach over to the RED C connection..
From my mere 2D viewing perspective, that right C11 connection seems
AWFULLY close to that ground plane mass, just to the right, beside it.
If there is a connection created it will be equivalent to a closed switch condition.
A surgical scalpel or #11 Exacto blade in its handle would permit cutting and peeling off, some of the adjunct ground plane for greater clearance / proximity of that right C11 connection.
AL FIN . . . . .
Place one meter probe toYELLOW B and look down to your encoder chip and I have that YELLOW foil path maked . . . UP TO . . . the point where it disappears underneath the white silk screen coating / resist. Using the other probe to each of those nearby I.C. pins should show a short to the one that the YELLOW foil is connected to . Keep that probe on that connection and take the prior connection of the other probe to Yellow B and move it up to YELLOW A. Now if that microswitch button is presssed, it should show a short, indicating all is well through the switch to the decoder pin connection, then as the switch is deactivated, an open circuit should be present.
Repeat the same test sequence for your twin RED switch and its path of the RED marked up section.
On that one search, at the decoder IC you might suspect that the required pin will be one pin up higher, just judging by the lay of the YELLOW and RED foil paths..
Hint of the month . . . . .
On correcting your over exuberant solder blob deposits and if you neither have a solder sucker nor So(l)der Wick***
Hold the board up high in the air with the overladen solder joints facing the floor.
Get your iron ready with it freshly tinned so that it looks like it is chrome plated and then tap it once to dislodge any excess solder.
Move its tip upward to meet and heat a fat solder blob and as it heats the excess solder will run down and deposit on your tip.
With experience you can carry off just the right amount of excss solder, or you can drain most all of it off and then depend upon a later reflow soldering with a stopping at just the right amount being added then.
In either case, you need to reflow the solder on those joints after the board is inverted, over to its normal working position.
*** You'se Limeys just might be using " Wycke ", instead.
BOARD REFERENCING . . . . .
https://i.ibb.co/rspV4Ln/Optical-Mouse-Circuit-Trail-II.jpg
Thaaaaaaassssssit . . . . .
73's de Edd . . . . .
I'd give my right arm to be ambidextrous.
.
... I don't know what to do now...
