Odometer Repair

[Epyontronic]

I need help finding equivalent parts to repair my Odometer to one of my cars. So the problem was that the Odometer display wouldnt show, stopped working. Everything else on the gauge cluster worked. When I took it apart, C3 Capacitor was blown. I went ahead and replaced the surrounding Capacitors being 10uf/50v as listed below. Plugged everything back in and still nothing. So I took apart again and checked all connections, all the surface mount chips had good connections. I checked the below described diodes and transistors. Used my desolder gun to remove them and check with meter as they looked corroded and two of them pretty much crumbled when removing (the leads that is). So now I am stuck needing replacements.

So this was taken from another forum. I need to know TR6, DA1 and DA2 (in red lettering below) equivalent replacements. This is for a 1993 Mazda RX7 car. This is the only information I have, so i dont know any more about the diodes and transistors.


Capacitors (Values shown)(Temp on all Caps: 105*C)
C1: 10uF, 50V, DigiKey P/N: 493-1890-ND
C2: 47uF, 25V, DigiKey P/N: P5539-ND
C3: 1000uF, 6.3V, DigiKey P/N: P10199-ND
C4: 1uF, 50V, DigiKey P/N: 565-1332-ND
C5: *Surface mount device on backside of board*
C6: 1uF, 50V, DigiKey P/N: 565-1332-ND
C7: *Surface mount device on backside of board*
C8: *Surface mount device on backside of board*
C9: R33 (line 1) BP (line 2), 50V, *P/N search suggests 33uF*
C10: *Surface mount device on backside of board*
C11: 2.2uF, 50V, DigiKey P/N: P13462-ND
C12: 10uF, 50V, DigiKey P/N: 493-1890-ND
C13: 1uF, 50V, DigiKey P/N: 565-1332-ND
C14: *Surface mount device on backside of board*
C15: 0.015uF, 50V, Mouser P/N: 80-MMK5153J50J01TA18 *CAUTION: Refer to Post #25!*
C16: 2.2, 50V, *Need capacitance value, could be uF or pF*
C17: 1, 50V, *Need capacitance value, could be uF or pF*

Resistors:
R10: 20?, 5% Tolerance (stamped 20?J)
R18: 20k?, 5% Tolerance
R25: 10k?, 5% Tolerance
VR: 200k?, Digikey P/N: 3306K-204-ND, manufacturer P/N: 3306K-1-204

Integrated Circuits:
IC1: 744C14A
IC2: TA78DS
IC3: 93C56EN
IC4: L2903 *not 12903 from the photos*
IC5: D75108GF(A)
IC6: AN8363UBK
IC7: M6544

Power Transistors:
TR1: D1922 (line 1), E (under last 2)
TR2: D1922 (line 1), E (under last 2)
TR3: G8 (device is very small, next to ZD6)
TR4: B1217
TR5: C458 (line 1), D (line 2), 3D1 (line 3), Google " transistor 2SC458"*
TR6: A143 (line 1), X.SZ (line 2)
TR7: C144 (line 1), ESZ (line 2), Google this P/N NTE123AP*
TR8: C144 (line 1), ESZ (line 2), Google this P/N NTE123AP*
TR9: C1214 (line 1), C (under last 4)

* - Search on Google resulted in transistor for purchase on other sites (not DigiKey or Mouser Electronics).

Diode Arrays:
DA1: P209 (line 1), S. X (line 2)
DA2: DA218

Resistor Arrays:
RA1: *Not Installed*
RA2: E10k?39, *Implies 10k? resistance)

Crystal:
XTAL: 4190A (line 1), 3N2 (line 2)

Diodes:
D1: *No markings*
D2: *No markings*
D3: *No markings*
D4: *No markings*
D5: *No markings*

Zener Diodes:
ZD1: *Illegible*
ZD2: *Illegible*
ZD3: *Illegible*
ZD4: 1N4742A, DigiKey P/N: 1N4742AFSCT-ND, Radio Shack P/N: 2760563
ZD5: 5 *Partial*
ZD6: PZ627
ZD7: *Illegible*
ZD8: 3 *Partial*
ZD9: 3 *Partial*
ZD10: 30 *Partial*

Thanks,
Brent

[SMdude]

You need to check that the 5v supply that powers the IC's is working.
If you had blown caps, perhaps higher voltage is getting through.
Are you able to get another odometer the same?
If so, just swap the EEprom and your original milage will be present(assuming the eeprom has not been fried from overvoltage)

You could also try:
http://www.digital-kaos.co.uk/forums/forumdisplay.php/174-DashBoard

You will never look at a low milage second hand car the same after seeing this forum!! 

Cheers

[Epyontronic]

Its actually a common problem with the early years rx7 3rd gens. 

I can get another but wont be usdm, however, I can still convert it to read in miles vs km. Just taking a gamble not knowing if the replacement gauge works or not when buying used. I can buy one new, but I dont want to pay over $700 USD and its not in miles, in km.

I might just have to do that, kind of sucks when I just need to get 3 replacement parts to try it out. yeah Ill have to swap over the mileage chip.

[A@ron]

btw if it comes down to buying a replacement cluster I'd try sending your current one to united radio for repair if the new ones are $700!

TR6 - I bet it's a 2SA143. It's not unusual for part #s to be shortened on small components.

[Epyontronic]

Thanks, ill contact them and see what they say.

I also contacted these guys: http://dnaspeedometers.com/

One rx7 dude sent his in to them, but he had  a used replacement gauge and swapped old gaue stuff to the replacement, so his original one wast actually repaired.

This stuff is straight forward to work on, I just need the parts. I contacted digikey and they werent able to help me...

[A@ron]

I'm still working on finding the parts for you
the transistor is above.

DA2 looks to be one of these possibly http://www.ebay.com/itm/5pcs-10pcs-DA218S-DA218-S-Transistor-TO-92-100-ROHM-New-And-Genuine-/182443057449?var=&hash=item2a7a742129:m:mvnfpCAapEBNYEdBYaP2pvQ

[Epyontronic]

Awesome, that should work I think. Im assuming the letters below the part number printer on the part dont have to match?

Attached is a picture of the ones I removed. those letters dont match with what the list shows in my original post, which was taken from another person.

[Epyontronic]

So it looks like these might work:

TR6 (A143): http://www.ebay.com/itm/10-PCS-DTA143XSA-TO-92S-DTA143-A143-Digital-transistors-built-in-resistors/371682103510?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

DA2 (DA218): http://www.ebay.com/itm/5pcs-10pcs-DA218S-DA218-S-Transistor-TO-92-100-ROHM-New-And-Genuine/182443057449?ssPageName=STRK%3AMEBIDX%3AIT&var=485021559414&_trksid=p2060353.m1438.l2649

DA1 (P209): still looking

Any Rejections so far to these replacements?

[Johncanfield]

The odometer actually runs backwards in our motorhome  (Freightliner chassis), service said they could replace the module but they could not by US law reset the mileage to reflect actual. I know the real mileage from pulling data from the OBDPII port.