Help me identify this LampLinc component

[Traditore]

Hi,

I have two failed LampLincs. Each has two blown capacitors (35V 470uF and 16V 100uF), which I've replaced. But there's a third problematic component I can't identify for sure. A Google search for 221AP96 yields nothing.

 

On the front side, it's soldered to Y1.

Could it be a crystal? If so, how do I determine its value?

I'd like to order a replacement online.

[hart2hart]

Y is a crystal and I’m of no help beyond that on specs.

Have you run continuity checks to confirm that there are no broken traces where capacitors leaked snd failed. Board looks rough next to them.

[Traditore]

No, I haven't yet. I'll get to that later. Not worth doing now unless I can also replace the crystal.

[Brian H]

One thing to be real careful with. The +35V side of the capacitor and the +5 Logic supply are tied directly to the Line input from the wall socket.

I would also check the 30 Volt Zener diode. That is connected across the 470uF/35V capacitor. In the main 30 Volt DC supply. The earlier hardware version. Where noted for failing or getting warm enough to actually fall off the PCB or blacken the PCB. Your photo looks like the later revision board with a different 30V Zener that may have been an improvement over the older revisions.

I replaced the 470uf/35V caps in many of the 2456S3 relay type modules. One started pulsing On and Off at about a 30 cycle rate. One had a shorted 30V Zener that made the module look dead.

If they are completely dead. You may also want to check the fuse in the shrink tube. From the Line input pin to the PC Boards Line input connection.

This is what is in a older PLM. I believe its frequency was used in many of the Insteon modules.

Crystal 22.1184MHz, 18pF Load Y1 Through-hole Recommended:
Citizen model
CMR309T22.1184MABJTR

[Brian H]

How did you determine the crystal was bad?

Crystals are normally a reliable component.

I know a few have thought the component mounting glue was something oozing out of the crystal.

[Traditore]

I must admit that the ooze I see on the crystal and on the board might be glue. But if it is, well, it's not holding anything anymore. lol

I haven't removed the heatshrink tube to look at the fuse, but there's continuity between both ends of the line input wire. So that probably checks out. Also ran continuity checks on traces from underneath the board. All good.

Now, on to the 30V Zener diode... I don't know which one that is. Could you enlighten me? I'll then break out the multimeter and see what readings I get.

Thanks for all the help.

Edit: in the meantime, I took readings on a few of the diodes. About .450V one way and OL the other way.

[Brian H]

If the fuse has continuity. Then it should be OK.

D3 is the 30 volt Zener diode. One side would be on the 470uF + and the other side on the 470uF -. The + side of the 470uf would also have continuity to the AC Line pin.

In your second photo. From the top edge. On the right side of the 470uF cap. MOV1,D1 (black body), D3 (glass body), D9 (glass body).

[Traditore]

Thanks for identifying the right diode. Not too sure why you mentioned uF instead of V. Must be because we were also talking about caps earlier.

Anyway... I'm getting 0.6V forward bias and OL reverse bias. I believe it means this diode is neither opened nor shorted. And I have continuity to the black wire.

I tested other diodes on this PCB. Some produce similar readings. Others (D7, D8, D12) have V both ways, which is probably not a good sign.

Any other thoughts before I throw them in the garbage?

[Brian H]

If you have a Diode test in your meter.

The diodes should have a conductance in one direction and a high reading in the other direction. So the 30V diode should read like any other diode. If you don't have a Diode setting. Depending on the ohmmeters voltage on the probes. You should get a fairly low resistance in one direction and a much higher resistance in the other direction.

I don't understand your using a V reference. As resistance is in ohms. Unless you are reading the voltage across a diode while powered up.

I called out the capacitor by its value. Would have been clearer if I had said 470Uf/35V

[Traditore]

No need to power it up. A diode test on a DMM sends voltage across the leads. It's different than testing for resistance. Hence the V.

3 of the diodes have V readings both ways, where I should have OL on one side. Obviously not blocking the current anymore.

They're older ICON LampLincs. Not worth it. Garbage, it is.

But thanks for everyone's input.

[Brian H]

In may ~60 years of being an Electronic Technician. I have never seen a diode tested using the V reference. I used my meters ohms or Diode Test setting. So I have seen a new way to list a diodes test information. That was why I asked if you where powering things as voltage to me means powered up.

If you are getting close to the same in both directions. Does sound like they are shot.

Garbage or electronic recycle sound like a good way to go.

[larryllix]

On 6/3/2021 at 6:38 AM, Brian H said:

If you have a Diode test in your meter.

The diodes should have a conductance in one direction and a high reading in the other direction. So the 30V diode should read like any other diode. If you don't have a Diode setting. Depending on the ohmmeters voltage on the probes. You should get a fairly low resistance in one direction and a much higher resistance in the other direction.

I don't understand your using a V reference. As resistance is in ohms. Unless you are reading the voltage across a diode while powered up.

I called out the capacitor by its value. Would have been clearer if I had said 470Uf/35V

Many of my later DMM used a 1mA constant current as a resistance test current. Then the resistance (in Kohms) you read on the meter was also the voltage drop across the diode. Germanium diodes would read 0.3v+ and silicone diodes always read 0.6v+. It becomes a signature that I would look for when doing an forward and reverse voltage drop on a diode. I never thought of it as ohms as the reading would vary, based on the meter current supplied.

[Brian H]

Thank you for the clarification on the Diode V reading.

I got out my DMM users manual and looked at the display. For the Diode test. Sure enough the displayed number is the forward voltage drop on the diode being tested.

Thanks again on the proper information.

[ELA]

The constant current technique to measure resistance is limited by the basic R=E/I  equation.  Thus the maximum R that can be measured is therefore limited by both the voltage that the meter is using and also the constant current source value.   For that reason some meters will change the constant current source value depending upon the Resistance value they need to read.   A lower current source allows for higher resistance readings.   When a meter reads "OL"  it is being limited by either its voltage or current source.

Using the diode setting on a meter is measuring the junction voltage of the diode and is not related to resistance.  Unlike a resistor a diode is a non linear device.  You can also use the diode setting to measure some LEDs.   Red and Green LEDS have a lower junction voltage and a meter on the diode setting usually has enough voltage to both light the LED and display its forward voltage.  

       You can make a constant current source very easily using a 3 terminal voltage regulator.  I have one that I use with a 30volt power supply.  That along with a volt meter allows it to measure  Zener diodes and higher voltage LEDS such as White and Blue.

These tools all work great when measuring parts on the bench.  Measuring "in circuit"  is often much more difficult because of what we call "in-circuit effects"

Parallel pathways for current flow that adversely affect the accuracy of measurements.