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  1. #1
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    Mar 2005
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    Pacific Northwest
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    Default DIM failure DIY repair experience

    Been helping a friend with fixing his 02 XC with 145k miles for sale. Fixed a DIM failure so I thought I post a bit of info on it

    The DIM failure was the clock would just periodically start to advance on its own. Google shows people with various DIM problems fixing it by reflowing the solder around a main controller chip (the motorola chip). So we pulled the DIM and had a electronic tech with equipment reflowed that chip and now works perfect. I believe another common failure is garbled text in the message window.

    A couple of notes on this job

    1. You must remove and install DIM with battery disconnected. My friend blew a couple of DIM bulbs without doing this. Of course, dis/reconnect battery on this car requires a bit of caution to avoid damaging electronics. Search around if unfamiliar.

    2. This chip has lots of legs with very tight pitch. Definitely need someone with good skills + equipment. Don't want to touch this with a cheap Radioshack iron. Basically need to remove the bluish coating (some say acetone, my tech said he burned it off) and reflow the solder around the chip. We also reflowed the 2 resister arrays (lower left corner of the motorola chip, one is called RA6 (Resistor Array 6) as some people noted that.

    3. There are several spring legs/towers on the circuit board. These are actually electrical contacts to the gauges that gets sandwiched with the circuit board. My friend accidentally bent one of the legs and speedometer didn't work until it was straightened out for proper contact.

    Left info on this job here.

    http://www.freewebs.com/howardsvolvo....htm#948779827
    Last edited by howardc64; 01-24-2015 at 11:46 AM.
    Past Volvos : 01 V70 T5, 01/02 V70XC, 02 V70 NA, 00 V70XC
    Current EV/Hybrid : 13 Tesla S85, 11 Gen3 Prius
    Friends cars under my care 17 Audi A4 Quattro DSG (B9) 05 Audi A4 Manual 6sp Quattro (B7) 04 e320 V6 Auto, 05 Accord 2.4, 08 Element 2.4, 08 Camry Hybrid
    Past Others : 01/03 VW MK4 Turbo/NA/01M. Gen1 Prius, Gen1 CRV, Gen2 Rav4, 02 Town&Country, 06 Corolla, 12 Audi A4 Quattro (B8), 07 Civic 1.6
    https://sites.google.com/view/howardsvolvos

  2. #2
    Join Date
    Feb 2013
    Location
    Boston, MA
    Posts
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    Default

    No need to remove bluish coating, hot air gun perfectly reflows solder under it. If you remove the coating, you need to coat pins, otherwise fix won't last for long.
    2002 V70 (sold)
    2005 XC70 (Telos Road took it. Did a chassis swap)
    2016 XC60 (sold, P.O.S.)

  3. #3
    Join Date
    Mar 2005
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    Pacific Northwest
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    Default

    Quote Originally Posted by vtl View Post
    No need to remove bluish coating, hot air gun perfectly reflows solder under it. If you remove the coating, you need to coat pins, otherwise fix won't last for long.
    Interesting. What is the reason fix don't last without blue coating?
    Past Volvos : 01 V70 T5, 01/02 V70XC, 02 V70 NA, 00 V70XC
    Current EV/Hybrid : 13 Tesla S85, 11 Gen3 Prius
    Friends cars under my care 17 Audi A4 Quattro DSG (B9) 05 Audi A4 Manual 6sp Quattro (B7) 04 e320 V6 Auto, 05 Accord 2.4, 08 Element 2.4, 08 Camry Hybrid
    Past Others : 01/03 VW MK4 Turbo/NA/01M. Gen1 Prius, Gen1 CRV, Gen2 Rav4, 02 Town&Country, 06 Corolla, 12 Audi A4 Quattro (B8), 07 Civic 1.6
    https://sites.google.com/view/howardsvolvos

  4. #4
    Join Date
    Sep 2002
    Location
    Belgium
    Posts
    2,404

    Default

    The chip probably is an SMD (Surfaced Mounted Device) such as this one:
    http://szcanyi.en.alibaba.com/produc...AU_SMD_IC.html
    Even if this is not the case, soldering in very crowded areas is easily done with
    a gas soldering iron with the soldering tip removed, giving a very small torch
    and allowing to (re)solder without physical contact.
    It is a good method to avoid short circuits between adjacent connections.
    This is the general idea, although I have no idea if this specific soldering iron is any good :
    http://www.shoppingsquare.com.au/p_4...Soldering_Iron
    Willy
    Last edited by Willy; 01-25-2015 at 10:46 AM.
    144 GL (1974)--->244 GL (1982)--->940 GLE 2.3i (1992)--->XC70 2.5T (2004)--->XC90 T5 (2018)

  5. #5
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    Feb 2013
    Location
    Boston, MA
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    Default

    Quote Originally Posted by howardc64 View Post
    Interesting. What is the reason fix don't last without blue coating?
    http://en.wikipedia.org/wiki/Tin_pest (darn headless ecology zealots!)
    2002 V70 (sold)
    2005 XC70 (Telos Road took it. Did a chassis swap)
    2016 XC60 (sold, P.O.S.)

  6. #6
    Join Date
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    Pacific Northwest
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    Default

    Quote Originally Posted by vtl View Post
    http://en.wikipedia.org/wiki/Tin_pest (darn headless ecology zealots!)
    Thanks for the pointer. Read up more on tin pest on tin rich lead free solders.

    The tech that helped with reflowing the DIM also reflowed an 01 Toyota Rav4 ECU a couple of years back. He told me lead free solder joints weaken with vibration (I hope they have that solved by now for auto circuit boards!). I'm guessing the common 99-01 ABS problems might be similar issue? since reflow is the fix there as well.

    However, I don't see any coating on most lead free automotive logic boards. I wonder if the DIM is different or just design preference by the original designer?
    Past Volvos : 01 V70 T5, 01/02 V70XC, 02 V70 NA, 00 V70XC
    Current EV/Hybrid : 13 Tesla S85, 11 Gen3 Prius
    Friends cars under my care 17 Audi A4 Quattro DSG (B9) 05 Audi A4 Manual 6sp Quattro (B7) 04 e320 V6 Auto, 05 Accord 2.4, 08 Element 2.4, 08 Camry Hybrid
    Past Others : 01/03 VW MK4 Turbo/NA/01M. Gen1 Prius, Gen1 CRV, Gen2 Rav4, 02 Town&Country, 06 Corolla, 12 Audi A4 Quattro (B8), 07 Civic 1.6
    https://sites.google.com/view/howardsvolvos

  7. #7
    Join Date
    Feb 2013
    Location
    Boston, MA
    Posts
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    Default

    Tin pest problem was not expected, since commonly used tin-lead solder didn't have it, so mechanical design of most circuits hasn't been changed. Now eco solders are mostly stable thanks to bismuth.
    2002 V70 (sold)
    2005 XC70 (Telos Road took it. Did a chassis swap)
    2016 XC60 (sold, P.O.S.)

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