Request: service manual for Infinity SSW-210 (subwoofer)

[vtech]

Yes I still have it.
Suggest doing some voltage measurements around the output IC.---be carefull not to short pins with meter probe.

[wolfsongaudio]

Can you clue me in to the location of IC3? I can see IC1, IC2 and IC 4. Also what pins to measure between on IC3? I have a nice Fluke meter with precision pins so shorting should not be an issue.

mike

[vtech]

IC3 is the main amplifier part number STK4050. It is an encapsularted, 18 pin module that is usually mounted on a heatsink or covered by one. Here is a picture

Use any ground point as a reference and measure each pin( Pin number one starts at the left looking from top). Again, be careful as the pins are close and it is easy to slip up and create a short, more likely to cause IC damage.

[wolfsongaudio]

vtech,

Awesome. I will get those #s. Thanks again.

Mike

[wolfsongaudio]

Pin # 1=0v
2=-.03
3= 0
4= -60.62
5= -61.96
6= -.005
7= -.01
8= 44.4 drivers thump, hum and hiss while this pin is contacted
9= .01
10= -.01
11= 60.8
12= -61.67
13= 0
14= 61.76
15=61.64 drivers emit a single low vol. TICK
16= 0
17= 0
18= 0

Continued contact with pin 8 trips the relay. It resets after contact is broken.

[vtech]

Go back to pin4 and re-check ; Is it around negative 60 V? Any signs of R29 getting hot?
That reading is way off as it is almost sitting at negative rails.
(hope you have solder/desoldering ability)
Turn off, unplug from power and desolder(isolate) one side of resistor R29 and measure it's value on OHMS scale and post back your result. The idea of desoldering is to avoid false reading while inside the circuit.
Either of two things, you either have an open R29 (More likely) OR there is a bad internal front end transistor inside the STK chip. (Rather odd)

[wolfsongaudio]

vtech,

Thanks a ton for all the help.

pin 4 does in fact measure -61.66 V. I de-soldered one end of R 29 and it is open. No visible cracks or heat marks but it in fact open. R 30 right next to it measures 48 ohms so I know my fluke meter is working.

[vtech]

Bingo

All you need is a 10K 1/2 watt standard resistor.

[prowlervm]

Hey Vtech,
I noticed that you really helped out wolfsongaudio with regard to the Infinity SSW210. I could really use your help as well, if you don't mind. I'm new to this site and am by no means an electronic expert. I bought this sub new many years ago and I'm trying to resurrect my old, and awesome stereo. This thing gave out on me back then and here's what it's doing now:
It powers on and I get a slight hum but no bass. When wired by way of the low level inputs I can hear the source but it is very low and distorted. I took all of the readings from the amplifier pins, just like you asked of the other member, and here are the results:

Pin1 -.3
Pin2 -.3
Pin3 0
Pin4 -63.0
Pin5 -64.5
Pin6 -.9
Pin7 .7
Pin8 64.1
Pin9 -1.4
Pin10 -1.4
Pin11 64.5
Pin12 -66.1
Pin13 .1
Pin14 66
Pin15 65.1
Pin16 -.1
Pin17 -.1
Pin18 -.1

Not sure if you'd be able to spot something from these readings, but any insight would be GREATLY appreciated! Thanks in advance...
Vince

[vtech]

Hey Vince,

You know it looks like you have the same EXACT problem as wolfsongaudio. Desolder one side of R29 and measure it's value. Bet you are going to find it open. You see the key here is the reading on pin4. If it is riding anywhere close to one of the rails, it means two possible things' either the main IC is bad(rather unlikely) or that R29 is open causing it to float instead of being tied to ground. Looks very likely that you need a resistor too!