VCR Power Supply Hybrid Regulators

Version 1.29

Copyright © 1994-2007
Samuel M. Goldwasser
--- All Rights Reserved ---

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Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied:
  1. This notice is included in its entirety at the beginning.
  2. There is no charge except to cover the costs of copying.

Table of Contents


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    Preface

    Author and Copyright

    Author: Samuel M. Goldwasser

    For contact info, please see the Sci.Electronics.Repair FAQ Email Links Page.

    Copyright © 1994-2007
    All Rights Reserved

    Reproduction of this document in whole or in part is permitted if both of the following conditions are satisfied:

    1.This notice is included in its entirety at the beginning.
    2.There is no charge except to cover the costs of copying.

    Acknowledgements

    Much of this list was compiled from entries in the ECG Semiconductor Master Replacement Guide and from replies to postings on the sci.electronics.repair newsgroup.

    Data for a several of the parts (those marked with *) has been generously provided by: Colin M. (colinmc@mail.zynet.co.uk).

    "Note that a number of chips produce the same output voltage at two pins: These outputs are separate. Separate DC inputs are also required. Our thanks to Sanyo Semiconductor (Europe) GmbH for supplying data on these devices and to Eugene Trundle for technical advice.

    Original data taken from a reference pulished by Television magazine. Scanned in by Colin McCormick. All errors to be blamed on Logitech Direct OCR software."

    Device Pinouts Contributions

    This list was compiled from replies to postings on the USENET newsgroup: sci.electronics.repair and will be updated as new requests come in. Contributions are welcome. Please email in a format similar to those listed below. If you provide additional comments, your name and email address will be listed as well.

    DISCLAIMER

    While every effort has been made to assure that the pinout information in this document is accurate, errors are possible and sometimes the databooks themselves are even in conflict.

    We will not be responsible for damage to equipment, your ego, blown parts, county wide power outages, spontaneously generated mini (or larger) black holes, planetary disruptions, or personal injury that may result from the use of this material.


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    Introduction

    Scope and Purpose of this Document

    This document provides pinouts for some of the common hybrid multiple output voltage regulators used in a large number of VCRs. A good source for this information is the ECG Semiconductor Master Replacement Guide (or the SK/NTE or other similar databooks).

    Does My VCR Use a Hybrid Voltage Regulator?

    VCRs typically use one of these types of power supplies:
    1. Power transformer with linear regulator using 78/79XX parts or discrete components. The power transformer will be large and right near the AC line cord.

    2. Power transformer with hybrid regulator like STK5481 or any of its cousins - multioutput with some outputs switched by power on. Again, the power transformer will be large and right near the AC line cord. The regulator will be a black box with multiple pins soldered to a circuit board and will be mounted on a heatsink usually in the vicinity of the power transformer.

    3. Small switching power supply. Most common problems: shorted semiconductors, bad capacitors, open fusable resistors. In this case there is usually no large power transformer near the line input but a smaller transformer amidships. See the document: Notes on the Troubleshooting and Repair of Small Switchmode Power Supplies for info on these types of supplies.

    4. Combo of the previous (for example, a power transformer feeding a switching supply) - these are less common.

    When to Suspect the Regulator

    Failure of one or more outputs of the power supply can result in symptoms anywhere from a totally dead VCR to problems in one subsystem such as the tuner or display. Multiple systems failures are a likely indication of a power supply problem as well.

    Safe Troubleshooting of Hybrid Regulators

    WARNING: Read, understand, and follow the recommendations in the document: Safety Guidelines for High Voltage and/or Line Powered Equipment before attempting any power supply repairs. While most of the devices listed here operate at low voltages, there may be exceptions. And, you may be in the vicinity of exposed line voltage terminals when probing the hybrid's pins.

    Testing

    First identify a suitable ground for your multimeter. With the VCR unplugged, test for continuity between the ground pin of the regulator and the chassis or a metal shield. Don't use the hybrid's ground pin as clipping anything to it increases the chance of an unfortunate short circuit.

    Check the outputs with the VCR both on and off if possible. The on/off should change with the power unless the unswitched output is dead and thus everything is dead.

    If any are low or 0, the regulator is most likely bad. Failure of these regulator blocks is a very likely cause where a VCR exhibits multiple system failures. While it is possible for an excessive load to be dragging down the power supply output, failure of the hybrid regulator is a lot more likely.

    However, also check the input voltage - typical values are 20 - 30 V DC. Defective rectifier diodes or filter capacitors can result in a low voltage or high ripple input which can result in low, noisy, or unstable outputs.

    For erratic problems or those that only occur under certain operating conditions, monitor the outputs on an oscilloscope (a storage scope would be nice) to see if they dip or have any noise on them.


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    VCR Hybrid Voltage Regulator Pinouts

    STK791

    
VCR Regulator.

(From Ken Koskie (aw345@lafn.org).)

The voltages should be approximately the same in all modes: Off, EE, Play,
and Record.
 
Pin 1: VI1 6.7 V
Pin 2: VI1 6.7 V
Pin 3: 0.0V
Pin 4: 0.0V
Pin 5: VO  6.8 V
Pin 6: NC
Pin 7: GND
Pin 8: VI2 18.5 V

    STK5331

    
* Three output series regulator in an eight-pin package:

Pin 1: +5.1 V output
Pin 2: +6.05 V input
Pin 3: Load resistor
Pin 4: Load resistor
Pin 5: +12.3 V output
Pin 6: on/off
Pin 7: +30 V max input
Pin 8: Chassis

    STK5332

    
VCR Positive Voltage Regulator: 13 V at 1 A, 6.05 V at 1 A, 5.1 V at .5 A.

Pin 1: VO3 +5.1 V
Pin 2: VO2 +6.05 V
Pin 3: VI2
Pin 4: Vb
Pin 5: VO1 +13 V
Pin 6: Gnd/SW
Pin 7: VI1
Pin 8: Gnd

    STK5333 - ECG7036

    
VCR Positive Voltage Regulator. 15 V at 1 A, 5.8 V at 1 A, 5.1 V at 1 A,
8 Pin SIP.

Pin 1: GND
Pin 2: VO3 +5.1 V
Pin 3: VO2 +5.8 V
Pin 4: VI2
Pin 5: Vb
Pin 6: VO1 +15 V
Pin 7: SW
Pin 8: VI1

    STK5338

    
* Three output series regulator in an eight-pin package.

Pin 1: Chassis
Pin 2: 5.1 V output
Pin 3: 5.8V output
Pin 4: 30V max. do. input
Pin 5: Load resistor
Pin 6: 12.3V output
Pin 7: On/off switching
Pin 8: 30V max d.c. input

    STK5339

    
* Three-output series regulator in an eight-pin package.

Pin 1: Chassis
Pin 2: +5.1 V output
Pin 3: +5.8 V output
Pin 4: +30 V max input
Pin 5: Load resistor
Pin 6: +12.3 V output
Pin 7: On/off switching
Pin 8: +30 V max input

    STK5342 - ECG7035

    
VCR Positive Voltage Regulator. 12.3 V @ 1A, 6.0 V @ 1A, 5.3 V @ .6 A.

Pin 1: VO3 +5.25 V
Pin 2: VO2 +6.0 V
Pin 3: Vb
Pin 4: Vb
Pin 5: VO1 +12.3 V
Pin 6: Cutoff
Pin 7: VI1
Pin 8: GND

    STK5372 - ECG1883

    
VCR Positive Voltage Regulator. 12.1 V @ .8 A, 12 V @ .8 A, 5.3 V @ 1 A.
8 pin SIP.

Pin 1: VO3 5.3 V (switched)
Pin 2: Cutoff (control input for 12 V output)
Pin 3: VI2 (input for VO3, 10 V typical)
Pin 4: VO2 12 V (switched)
Pin 5: VO1 12.1 V (and input to VO2)
Pin 6: Vb (control for VO1)
Pin 7: VI1 (input for 12 V outputs, 18 V typical)
Pin 8: Gnd

    STK5421

    
* Four-output series regulator in a fifteen-pin package.

Pin 1: +12.3 V output
Pin 2: Load resistor
Pin 3: +12 V output (unswitched)
Pin 4: Decoupling
Pin 5: +30 V max input
Pin 6: Link to pin 5
Pin 7: +30 V max input.
Pin 8: +16 V output (unswitched)
Pin 9: Link to pin 8
Pin 10: +9.55V output
Pin 11: Load resistor
Pin 12: Chassis
Pin 13: On/off switching
Pin 14: Decoupling
Pin 15: Decoupling

    STK5422

    
* Four output series regulator in a fifteen pin package.

Pin 1: +12V output
Pin 2: Load resistor
Pin 3: +12V output
Pin 4: Decoupling
Pin 5: +30 V max input
Pin 6: Link to pin 5
Pin 7: +30 V max input
Pin 8: +13 V output
Pin 9: Link to pin 8
Pin 10: +9.5 V output
Pin 11: Load resistor
Pin 12: Chassis
Pin 13: On/off switching
Pin 14: Decoupling
Pin 15: Decoupling

    STK5431

    
Pin 1:  Out 5.1 V
Pin 2:  NC
Pin 3:  Out 12 V
Pin 4:  Ctrk 12 V
Pin 5:  In 12 V
Pin 6:  In 5 V
Pin 7:  In 15 V
Pin 8:  In 9.5 V
Pin 9:  Out 15 V
Pin 10:  Out 9.5 V
Pin 11:  Ctrl 9.5 V
Pin 12:  Gnd
Pin 13:  Ctrl 4 V
Pin 14:  Ctrl .6 V
Pin 15:  Ctrl 15 V

    STK5436 - ECG1876

    
Pin 1:	VO4 +6V
Pin 2:	NC
Pin 3:	VO3 +12V
Pin 4:	Bypass
Pin 5:	VI2
Pin 6:	VO3 +12V
Pin 7:	VI1
Pin 8:	VO1 +13V
Pin 9:	VO1 +13V
Pin 10:	VO2 +9.5V
Pin 11:	IB2
Pin 12:	GND
Pin 13:	On/Off
Pin 14:	Bypass
Pin 15	Bypass

    STK5441 - ECG1734

    
VCR Positive Voltage Regulator.  12V @ 2A, 9V @ 1A, 5.5V @ .5A.  15 Pin SIP.

Pin 1:	VO3 +5.5 V
Pin 2:	NC
Pin 3:  NC
Pin 4:	NC
Pin 5:	NC
Pin 6:	VI2
Pin 7:	VI1
Pin 8:	VO1 +12V
Pin 9:	VO1 +12V
Pin 10:	VO2 +9V
Pin 11:	Bias
Pin 12:	GND
Pin 13:	Cutoff
Pin 14:	Bypass
Pin 15:	Ripple Filter

    STK5451 - ECG1735

    
VCR Positive Voltage Regulator.   16V @ 1A, 12V @ 1A, 12V @ 1.5 A,
11.9 V @ 1.5A.

Pin 1:  11.9 V Output 4
Pin 2:  Control Volt
Pin 3:  DC Input 2
Pin 4:  Reference input
Pin 5:  12V Output 3
Pin 6:  Reference input
Pin 7:  16V/12V Output 1/2
Pin 8:  Reference input
Pin 9:  DC input 2
Pin 10: DC input 1
Pin 11: Hi/Lo volt switch
Pin 12: GND
Pin 13: on/off control
Pin 14: Heater switch (??)
Pin 15: Reference input

    STK5461 - ECG7027

    
VCR Positive Voltage Regulator.  12V @ 1A, 12V @ 1A, 5.1V @ .5A.  15 Pin SIP.

Pin 1:	VO3 +5.1 V
Pin 2:	NC
Pin 3:  NC
Pin 4:	NC
Pin 5:	NC
Pin 6:	VI2
Pin 7:	VI1
Pin 8:	VI1
Pin 9:	VO1 +12V
Pin 10:	VO2 +12V
Pin 11:	IB2
Pin 12:	GND
Pin 13:	Cutoff VO1
Pin 14:	Cutoff VO2
Pin 15:	IB1

    STK5464 - ECG7023

    
VCR Positive Voltage Regulator.  12V @ 1A, 12V @ 1A, 5.3V @ 1A.  12 Pin SIP.

Measured input voltages (your mileage may vary): VI1 = 18 V, VI2 = 8.5 V

Pin 1:	VO3 +5.3 V
Pin 2:	NC
Pin 3:  NC
Pin 4:	NC
Pin 5:	VI2
Pin 6:	VI1
Pin 7:	VI1
Pin 8:	VO2 +12V
Pin 9:	VO1 +12V
Pin 10:	VO1/VO2 Cutoff
Pin 11:	GND
Pin 12:	Vb

    STK5466 - ECG1821

    
VCR Positive Voltage Regulator.

Pin 1: VO3 +5.3 V
Pin 2: NC
Pin 3: NC
Pin 4: NC
Pin 5: NC
Pin 6: VI3
Pin 7: VI1 and 2
Pin 8: VI1 and 2
Pin 9: VO2 +12 V
Pin 10: VO1 +12 V
Pin 11: NC
Pin 12: GND
Pin 13: On/off
Pin 14: On/off
Pin 15: Vb (probably around 13-14 V)

    STK5467

    
* Three output series regulator in a twelve pin package.

Pin l: +5.3 V Output
Pin 2: NC
Pin 3: NC
Pin 4: NC
Pin 5: +30 V max input
Pin 6: +30 V max input
Pin 7: Link to pin 6
Pin 8: +12.1 V output
Pin 9: +12.1 V output
Pin 10: Pin 9 output cut off
Pin 11: Chassis
Pin 12: Load resistor

    STK5471 - ECG1822

    
VCR Positive Voltage Regulator.  12 V @ 1.5 A, 12 V @ 1.5 A, 5.3 V @ .5 A.
10 Pin SIPP.

Pin 1: Iout 3 for 5.3 V
Pin 2: Vout 3 control
Pin 3: Iin 3
Pin 4: Iout 2 for 12 V (emitter)
Pin 5: Ib 2 (base)
Pin 6: Iin 2 (collector)
Pin 7: Iout 1 for 12 V (emitter)
Pin 8: Ib 1 (base)
Pin 9: Iin 1 (collector)
Pin 10: GND

It appears as though Pin 1 is the output of an IC regulator for the 5.3 V.
Pin 3 is the Vin - 20 V typ.  Pin 2 is some kind of on off control.

Pins 4-6 and 7-9 are the emitter, base, and collector for the two
12 V outputs.  These are simple Darlington transistors setup to
drive the outputs in an emitter follower configuration.
Vin typ of 30 V.

Deduced from schematic in ECG.

    STK5477 - ECG7034

    
VCR Positive Voltage Regulator.  12v @ 1A, 12V @ 1A, 5.1V @ 1A.

Pin 1:  GND
Pin 2:  VI2
Pin 3:  N/C
Pin 4:  VO3 +5.1V
Pin 5:  VO2 +12V
Pin 6:  VB
Pin 7:  VI1
Pin 8:  VO1 +12V
Pin 9:  VB
Pin 10: VI1
Pin 11: N/C
Pin 12: GND

    STK5481 - ECG1823

       
Pin 1:	Ib3
Pin 2:	VI2
Pin 3:	VO4 +5.3 V
Pin 4:	VO3 +12.1 V
Pin 5:	VO3/VO4 ON/OFF
Pin 6:	VO2 +12.2 V
Pin 7:	Ib2
Pin 8:	VI1
Pin 9:	VO1 +12.0 V
Pin 10:	Ib1
Pin 11:	VI1
Pin 12:	GND

    STK5482

    
* Four output series regulator in a fifteen pin package.

Pin 1: Chassis
Pin 2: +30 V max input
Pin 3: +5.1 V output
Pin 4: +12 V output
Pin 5: Bias/+12V output switching
Pin 6: +30 V max input
Pin 7: +5.8 V output
Pin 8: Bias/pin 7 output switching
Pin 9: Link to pin 2
Pin 10: Load resistor/pin 7 output switching
Pin 11: +13/+15V output
Pin 12: Pin 11 output switching
Pin 13: Link to pin 6
Pin 14: Pin 11 output switching
Pin 15: Chassis

    STK5486 - ECG7038

    
VCR Positive Voltage Regulator.  13V @ 1A, 12.2V @ 1A, 6V @ 1A, 5.1V @ 1A,
5.1V @ 1A, 15 Pin SIP.

Pin 1:	VO5 +5.1 V
Pin 2:	NC
Pin 3:  VO4 +5.1 V
Pin 4:	VI2
Pin 5:	NC
Pin 6:	VO3 +6 V
Pin 7:	VB
Pin 8:	VB
Pin 9:	VO2 +12.2 V
Pin 10: Cutoff
Pin 11:	VI1
Pin 12:	VO1 +13 V
Pin 13:	Cutoff
Pin 14:	VI1
Pin 15:	GND


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