[TechAssist] Sony KV27S20 AA2 blows Q601 & Q602
- From: "Peter oliver" <oliver_peter1@xxxxxxxxxxx>
- To: techassist@xxxxxxxxxxxxx
- Date: Tue, 25 Nov 2003 03:14:03 +0000
Sony
KV20S20
AA2
MFD 1996 (main chassis with seprate power supply board, discrete components,
Dampered HOT)
Set was brought in as a Military Shipping Damage Claim. Found Q601 &
Q602 shorted, R607 open, No apparent cracks on board or visble trama to the
set. The HOT seemed to be ok although it read 12 ohm B-E out of circuit
(accross damper network) (tried repacing it just in case no help), VDR601
reads as open, C609, C610, C611, C612 read within tolleance on a BK 830
capacitace meter. Main filter caps test ok, and output voltage off main full
wave recifier is ok. When set is pluged in will instantly blow Q601 & Q602
(2SC4834 M) and opens R607. Does not even get as far as fluxing up the HV.
The VDR601 1-810-974-11 is a mashushita ZNR V10431U according to its
markings (any one know if the Digikey part # P7257-ND is the same thing, it
is only $0.37 where as the Tritronics list on the 1-810-974-21 is $9.09 in
the sony packaging or even NTE 2V275 10mm?) [ I have the PDF's for the AA2
Chassis from sony and the Sams for the 32S20]
I am thinking on the following lines:
1. VDR601 was damaged and is activating at an erronously low volatge causing
power supply failure either from an intrinsic time related fault or from
being inadvertantly connected to 220v while on travel.
2. additonal componet faults causing failure
3. hidden shipping related damage not easily detetable (CRT ? But don't even
hear or feel the osc start)
Peter Oliver
Tucson Radio TV
_________________________________________________________________
Gift-shop online from the comfort of home at MSN Shopping! No crowds, free
parking. http://shopping.msn.com
*****************************************************************************
Lost Password:
http://www.tech-assist.org and select "Login Problems?".
Email Archives:
//www.freelists.org/archives/techassist/
Other related posts:
