Results 1 to 4 of 4

Thread: Radio Head Unit (EU 1992) Repair and Capacitor Replacement

Threaded View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    Jan 2018
    Location
    Near Stuttgart, Germany
    Posts
    246
    Blog Entries
    25

    Lightbulb Radio Head Unit (EU 1991) Repair and Capacitor Replacement

    A fellow NSX driver approached me after fixing all three of his amplifiers reporting issues with his radio. It worked but when listening to stations they were distorted and he mostly used it together with a CD changer adapter. The unit arrived last week, with an interesting modification to supply power to an extra set of speakers but nothing to worry about. Time to grab the active speakers, a cassette and a CD changer for a test run.


    Click image for larger version. 

Name:	PXL_20211113_102446303s.jpg 
Views:	811 
Size:	119.3 KB 
ID:	14381
    front
    Click image for larger version. 

Name:	PXL_20211113_102528886s.jpg 
Views:	595 
Size:	125.1 KB 
ID:	14382
    back
    Click image for larger version. 

Name:	PXL_20211113_102552058s.jpg 
Views:	630 
Size:	135.3 KB 
ID:	14383
    bottom

    Radio tuning and sensitivity were fine. The sound was indeed distorted - an effect that wasn't audible when playing cassette (which worked fine - including reverse and track skip so no belt replacement required) or CD. The sound got better after warming up but then the CD playback, which was working on one channel only, completely dropped out - suspect here is the OP amp near the CD changer socket as it's often affected by acid creep.
    Since the distortions were only present when the radio was playing it couldn't be the Z-diode from the last radio repair since that affected all sound sources equally.

    Next step was opening the case and investigating the PCBs for damage. It's the typical European RDS NSX radio with the extra large voltage stabilizing capacitors that leak substantially.
    Two capacitors had blown and, three where bulged and the two large ones leaking. The capacitors on the small power where leaking too but no damage had happened to the PCB yet.

    Click image for larger version. 

Name:	PXL_20211113_113353399s.jpg 
Views:	586 
Size:	142.4 KB 
ID:	14384
    bulged and vented capacitors
    Click image for larger version. 

Name:	PXL_20211113_113421742cs.jpg 
Views:	598 
Size:	154.2 KB 
ID:	14385
    soaked connectors and OP amp
    Click image for larger version. 

Name:	PXL_20211114_163146597cs.jpg 
Views:	557 
Size:	134.9 KB 
ID:	14386
    large leaking caps

    Click image for larger version. 

Name:	PXL_20211114_163321582s.jpg 
Views:	512 
Size:	143.3 KB 
ID:	14387
    acid leaks on the PCB ..
    Click image for larger version. 

Name:	PXL_20211114_163327948cs.jpg 
Views:	543 
Size:	116.8 KB 
ID:	14388
    .. underneath the flat cable connector ..
    Click image for larger version. 

Name:	PXL_20211114_162056229s.jpg 
Views:	540 
Size:	106.0 KB 
ID:	14389
    .. and on the power board

    To ensure a proper repair, the CD changer and the left flat cable connector were removed and investigated. Since there was no corrosion beyond the soldering points they were deemed fit for service and later re-installed. The OP amp and all contaminated silk screen was removed, no damaged tracks observed and everything cleaned, including the connectors.

    <to be continued>
    Last edited by Heineken; 20-11-2021 at 12:36 PM. Reason: typo
    1997 JDM Custom Order AT VIN 1400005 - Stock
    Heineken's Garage

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •