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HIC Identifying Component

Discussion in 'Troubleshooting and Repair' started by clockstick, Mar 20, 2019.

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  1. clockstick


    Mar 20, 2019
    Good day,

    This is a Light Switch out of a 1990 Mazda RX-7, some faulty wiring fried the Switch. The following component is the one that need replacement however I can not figure out what it is.

    Here are three pictures of the pictured component.


    Attached Files:

  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    Jan 21, 2010
    It appears to be a microphone. The marking on the board is "mic".

    The images are not good enough for me to be sure. Increased brightness would be good.
  3. clockstick


    Mar 20, 2019
    it says HIC on the Board.
    On the side of the Component it is;
    0 or O35-2
    It has 6 pins in a straight line
    Last edited: Mar 20, 2019
  4. Tha fios agaibh

    Tha fios agaibh

    Aug 11, 2014
    Looks like a solid state relay.
    How do you know it needs to be replaced?
    Have you replaced the light switch and it still doesn't work?
  5. 73's de Edd

    73's de Edd

    Aug 21, 2015
    Sir clockstick . . . . .

    Also I confirm as reading HIC . . . . . . no LEXA . . . turn on / off lights ! , pick up mike, is being incorporated on this board.
    I would guesstimate that is being a product PROPRIETARY potted module with its unidentified flying internal components.
    It seems to use two clip in END connections for both mounting and possibly electrical connections.
    OHM out to see if being shorted from one clip end to the other clip end , if so ohm out from the clip end that you have your pen tip on to see if it is reading .33 or 33 or 330 ohms of resistance from the very bottom ground plane . ( I can't positively read that resistors color rings. )

    Also check out ALL of the solder joints on that board vewy-VEWY- VEWY cawefuwwly . . . . ( a la Elmer Fudd.)

    To wit . . . . . look at your pen tip referencing and go up the very top of the pic to where you have 3 opened soldered connections. Then you drop down to the two soldered connections just below , and a bare aluminum indexing tab being just below them.
    Look at the left of the two solder joints, and on the viewable side, possibly it looks like it is starting to develop a floating ring solder joint .Let one develop FULLY, and you have an open or intermittent floating component lead connection.
    Back to the pen tip . . . . . even the DORMANT terminal just to the left in front of the pen nib, looks like it is starting to develop a circular solder ring fracture.

    Thaaaaaaaassit . . . .

    73's de Edd . . . . .

    Timely factoid . . . . Wifely / GF advice:
    Men have just two emotions: Hungry and Horny.
    So, if you see him without an erection, make him a sandwich.

  6. clockstick


    Mar 20, 2019
    73's de Edd,

    Thank you for the advice, I have six of these switches and of those only 1 works. i would like to repair them all if I could, however I have three with this component that is shot. I know it is bad as the top layer of the epoxy (or potting) is sticky, where as the switches that work this is not the case. The rest of the components on these boards that go bad are usually very consistent and easily replaceable. These however seem to be a bit of a problem. I am hoping to find a replacement or at the very least create something that will function as a replacement. I have done as you suggested here are the results;
    So Numbering 1-6 (6 being the pen tip)

    Bad Component
    1-6 = No Connection (NC)
    1-5 = 15050000 Ohm
    1-4 = NC
    1-3 = NC
    1-2 = NC

    Good Component
    1-6 = 804 ohm
    1-5 = 294 ohm
    1-4 = 14910000 ohm
    1-3 = 620 ohm
    1-2 = 751 ohm

    I also took the time to remove the component in question from this particular board, I have also attached the diagram and functionality check as per the service manual for the car, hoping it will help you gleam some information.

    Here is the following;

    In PCB SW_DIA 1.jpg
    The connector is looking at the component connector pins.
    In PCB SW-DIA 2.jpg
    The connector is looking at it from the component side of the connector (so the mirror of above)

    RD = Retractor Down
    RU = Retractor Up
    HR = Headlight Relay
    HBO = 12v Switched 10 A Fused
    TIG = Defrost Timer
    IL = Illumination
    BTN = 12V Batt 60A Fused
    TNS = Tailights/parking lights
    E = Ground
    BA = 12V Batt 30 A Fused
    HC = Headlight Cleaner
    DEF = Defrost Relay Ground
    TIG = 12v Switched 15 A Fused

    Please see the trace diagram I did with the component, after this I have determined that in some form it dims the instrument lighting to pin IL. Now I am definitely beyond my depth here I am not too proud to admit that.

    Attached Files:

    Last edited: Mar 21, 2019
  7. clockstick


    Mar 20, 2019
    Also see attached the front and rear with the component in question removed.
    I also notice there is damage to the following components on this board and they would of course be replaced;

    Attached Files:

    Last edited: Mar 21, 2019
  8. 73's de Edd

    73's de Edd

    Aug 21, 2015
    Sir clockstick . . . .

    ALAS . . .I see that I was working without your last two info supplementals. .I will rework the bottom schema with the now CONFIRMED PNP lamp driver transistor.
    What main board numbers does the pot mount between ?

    With your forthcoming info, It just looks like your mystery unit should fall under the " Panel Lamp Control Switch" ***(PCB / potted Module).

    Looking at the top pic which you supplied . . . . now having its possible power flow marked up.

    Watch the DC 12 battey power come in from the top left corner as the RED arrows and travel to the Light switch, where, if turned on, it supplies power to one connection of the PLCS *** PCB. You then have your variable pot for lamp brightness control, using up 3 more connections and then finally there is the one connection with the BLACK arrows being the ground return connection.
    That only leaves the connection above with the varied DC output power to then travel the ORANGE arrow path and feed 3 mini illumination lamps, at the right , at the left and one at the top.

    Looking at the botttom schematic supplied with the transistors . . .repeated below . . . .that looks exactly like what you would expect to be within the PLCS potted module.

    On one of your other schematics, it does hint of that, with it showing a single PNP transistor being within the PLCS block.

    Question now . . . . are these transistors present and being mounted somewhere on the whole board ?

    On the provided schematic with the transistors. The ZETEX small signal is just as I would expect, and being the driver. But you show the power . . lamp driver transistor, as being a 2SB1155 power transistor and a NPN type . . .which it is not . . .it is being a PNP. Its NPN like match mate would be a 2SD1706.
    Plus you placed no arrow on the emitter for its further confirmation . . . . so I made it into an NPN. And for that to be a complete discrete darlington configuration of two direct coupled transistors, the BLUE , inter collector connection would be needed.

    I am in need of further defining explanation of the
    18-TNS . . . apparently all being the same connection point.

    Lets look at the schematic and see how it would be expected to work with using the dual darlington configuration with two NPN's.
    You would have the pot, which you disassembled and shown us its internals, ( without its addditional single twist in mini lamp socket ) as my entry at the top left corner.
    You see the reduced DC input from the dash panels lamp supply coming in at your marked . . .17-pin 3 . . . and R4, which has been selected so as to produce JUST enough voltage after passing to pin 3 of the pot and having the pot at max such that pot wiper connection 1 is resting right against it and that full voltge then passes down to the 100 ohm series resistor to provide maximum base drive to ZETEX688B. That then fully drives the power output transistor which supplies the full 12VDC coming in to pin 6 of the PLCS . . . . thru the conducting C-E junction of the power output transistor to all of the 3 lamps. ( This is where I need the 18 TNS info as I see the top right connection to R2 as grounded but the two C-E bottom connections and that 77 ????.
    steering diode, would not be .)
    Considering that the first info and pot setting above, had the lamps at max bright . . . as being referenced as to whether the main dash lamps were dimmed.
    If the pot was rotated with the wiper 1 moving towards 2 terminal, the lights would dim by the wiper approaching 2 and 2 then passes thru R2 to ground. with that R2 value selected so that 2 cannot totally reach being grounding out by 200 ohms of separation...
    That then leaves the affected display illumination at a just discernible level, but not being totally blacked out.

    All of the above needs your further observations and feedback info, to properly work out

    The top mark up photo seems to account for all, except the adjusted DC power input from the dash dimmed lighting supply.
    On the bottom schema the assigned wiring connections coming into the pot you wrote in, DO agree with my added on 1-2-3 terminals of the pot. But if you go to the actual markings placed on the pot itself :
    1 is min resistance CCW position
    2 is the wiper
    3 is the max resistance CW position

    Now . . .overall . . . . What say ye . . . ?



    73's de Edd . . . . .

    My auntie gave me a walkie-talkie for my birthday. She says if I'm good, she'll give me the other one next year.

    Last edited: Mar 21, 2019
  9. clockstick


    Mar 20, 2019
    The Pot Mounts on the Main board as follows:
    Dimmer Pot - Main Board Pin
    5(Opposite Side solder joint for the light bulb)-18

    2) See the attached picture for where ZTX688B and 2SD1706 are mounted.

    3) Pin 18 TNS Component 77 is pictured at the end of my pen tip it protrudes to the other side where it connects to pin 18 and TNS pathway.

    I know that this potted mystery component is in-fact something to do with the dimming feature for the dash, and instrument lighting. Another switch I have where the mystery component is also bad all functions except the dimming of the instrument lighting it is on full brightness. So I can confirm that this component is in fact tied to the dimming feature. Is there a way to disolve the potting compound and see the components inside well enough to identify them in order to assist?

    Attached Files:

  10. clockstick


    Mar 20, 2019
    To ensure I did not confuse myself I did a VISIO drawing of the Mystery Component circuit.

    Attached Files:

  11. clockstick


    Mar 20, 2019
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