Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
jango2
 
Posts: n/a
Default Alpine CVA-1005

Hi,
I got this Alpine CVA-1005 for repair which has been to a couple of
technicians before me , all who've given up on it. Symptom , no signs
of life though it seems to draw 0.35 amps from my ps ) I open the hide
away unit and while tracing supply and acc lines ( i don't have a
service manual) i reach the first power switching transistor , a
2SB1417 ( Q 8027 on the pcb ). I notice that someone has messed around
in this region. Strange thing is, the base lead of the transistor ,
doesn't seem to be going anywhere , apart from to the 1.5 K ohm
resistor tied to supply and the emitter of the transistor. Obviously
the base would have to be connected to some device that would pull it
low , when on, for the transistor to be forward biased. I pulled out
the transistor and examined the copper trace and, zilch , no connection
whatsoever. So my guess is there's a wire missing and i need to know
between where and what.
If someone has the service manual or a working piece, i'd be greatly
obliged if they could look this up and inform me.
Emitter 12v (+B)
Collector 0v (output switched dc)
Base 12v (control)
I don't think buying a service manual would be a good idea as i rarely
get these units.
Thanx in advance,
Jango.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Alpine car amp model:3548 [email protected] Electronics Repair 1 July 6th 05 03:47 PM
Alpine DVD touchscreen BOB URZ Electronics Repair 0 May 25th 05 09:55 PM
Alpine Bearing-JC-Graziano lathe bearings Gunner Metalworking 5 May 21st 05 05:20 PM
Alpine CDM-7861 Car CD Player Problems BeefJerky Electronics Repair 0 August 19th 04 12:48 AM
hopeless question about lamp in Alpine CDA-7861 its you Electronics Repair 1 July 25th 03 01:24 AM


All times are GMT +1. The time now is 03:45 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"