Im rebuilding this amp pretty much all of it since more then half the parts are missing off the board.
My question is There are 1 ohm resistors in the power supply section there are 2 of them.
In the reference 700sx they are using sandstone resistors but in the 700s whats there now is just regular resistors 5 watt but they are to long and big to make it look like a professional job. Wondering do i use smaller resistors like 2 watt or do i get the sandstone resistors (the lenght i need)
My question is There are 1 ohm resistors in the power supply section there are 2 of them.
In the reference 700sx they are using sandstone resistors but in the 700s whats there now is just regular resistors 5 watt but they are to long and big to make it look like a professional job. Wondering do i use smaller resistors like 2 watt or do i get the sandstone resistors (the lenght i need)
From the factory, lots of these snubber resistors looked less than professional. If it has a 5w, it may need a 5w. They run very hot and a lower wattage resistor may fail.
Ok i put new emitter reisitors in the amp and rebuilt all of the power supply. i also put new driver boards in it. Right channel is dead left channel distorts like crazy wondering where i go from here?
Run all switches and pots through their entire range (repeatedly for the switches) while the amp is playing to see if either channel produces clean audio.
yeah a couple switches are dirty i messed with them and the channel that was playing now that doesnt work either and i get static like crazy through the speaker. so guess ill have to get some cleaner or some new switches
Without exception, every soundstream of this era has problems with the switches. They should be checked even if all channels are playing because there's a good chance that they will cause problems when the amp is installed.
ok the left channel distorts like crazy i tracked that down to the preamp board broken solder connection or something cause if i hold it the left channel plays fine
right channel is dead no output no static nothing wondering what i should check
right channel is dead no output no static nothing wondering what i should check
Did the right channel begin to play when you moved the switches?
You may have a broken trace on the driver board or on the main board where they connect. The first thing you would do is to re-solder all of the connections. If that doesn't work and you feel that the problem is definitely in that area, desolder and remove the driver board and examine all pads on both boards (where they connect) with a lighted magnifying glass. You may have to use desoldering braid to remove as much solder as possible to see breaks.
I always recommend using ChipQuik solder alloy and reduced soldering iron temperatures when desoldering these (and other) driver boards. It makes it almost impossible to do damage to the boards.
You may have a broken trace on the driver board or on the main board where they connect. The first thing you would do is to re-solder all of the connections. If that doesn't work and you feel that the problem is definitely in that area, desolder and remove the driver board and examine all pads on both boards (where they connect) with a lighted magnifying glass. You may have to use desoldering braid to remove as much solder as possible to see breaks.
I always recommend using ChipQuik solder alloy and reduced soldering iron temperatures when desoldering these (and other) driver boards. It makes it almost impossible to do damage to the boards.
ok i tracked the right channel down to one of the driver boards gonna resolder the thing and the left channel is somewhere on the preamp board gonna resolder that as well.
The other thing is when u turn the gains up on both channels there is no difference on sound doesnt see that either gain is working wondering what this might be
The other thing is when u turn the gains up on both channels there is no difference on sound doesnt see that either gain is working wondering what this might be
How about a thread resurrection ?
I have a 700s that was in a car I bought but non functioning. I took the back off and found leaking esr caps and blown power supply fet's. So I replaced them and upon testing it blew the Q47,48,50 fets again on the lead tied to the + side of the esr bank. Obviously there is a short somewhere. I did manage to get a schematic from SS but is it worth fixing and where is the likely trouble area. Any help is appreciated
Thanks
I have a 700s that was in a car I bought but non functioning. I took the back off and found leaking esr caps and blown power supply fet's. So I replaced them and upon testing it blew the Q47,48,50 fets again on the lead tied to the + side of the esr bank. Obviously there is a short somewhere. I did manage to get a schematic from SS but is it worth fixing and where is the likely trouble area. Any help is appreciated
Thanks
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Check the drivers for shorts/leakage.. Arrows pointing to them in the pics..
Also check the following..
All TIP102's and TIP107's fo shorts /leakage.. You should get nothng near 0
Check all gate resistors for the power supply fets as well..
I would start there if you havent already and if everything checks fine then we can go from there..
Also check the following..
All TIP102's and TIP107's fo shorts /leakage.. You should get nothng near 0
Check all gate resistors for the power supply fets as well..
I would start there if you havent already and if everything checks fine then we can go from there..
mike49504 thanks for the reply. This is interesting knowing where to start at least.
Drivers checked .58v on forward bias, .49v , .50v on reverse bias Q46, 1.0v, open on Q53
So it seems the drivers are bad. Trying to reposition Q53 for a better look at the p/n the metal back peeled off, obviously a goner
Gate resistors are gone, value should be 3.3 i'm reading 1.6-1.8 on r181-r183 and 16,open, 202 on r178-r179. Took a magnifying glass to notice the burn marks on them (getting old sucks lol) They might have been there the whole time.
A few of the power supply fets were smoked when testing it so they will all need to be redone.
TIP102/107 I am not sure where to find those, none of the part numbers cross.
I do have the schematic and might as well upload it so we are on the same page if you don't have one.
Drivers checked .58v on forward bias, .49v , .50v on reverse bias Q46, 1.0v, open on Q53
So it seems the drivers are bad. Trying to reposition Q53 for a better look at the p/n the metal back peeled off, obviously a goner
Gate resistors are gone, value should be 3.3 i'm reading 1.6-1.8 on r181-r183 and 16,open, 202 on r178-r179. Took a magnifying glass to notice the burn marks on them (getting old sucks lol) They might have been there the whole time.
A few of the power supply fets were smoked when testing it so they will all need to be redone.
TIP102/107 I am not sure where to find those, none of the part numbers cross.
I do have the schematic and might as well upload it so we are on the same page if you don't have one.
I just checked the dual positive and dual negative rectifiers at D16/D18 And D13/D20 respectively. I am getting 0v both directions on the positive rectifiers D16/D18 and .42v/1.5V on the negative rectifiers D13/D18
TIP102 and TIP107 are the outputs they are on the bottom side of the amp..
Take the bad power supply fets out of circuit then re-check the drivers for the power supply fets..
Heres a pic of the drivers (red arrows pointing to them) but make sure you remove the bad fets before you test
Take the bad power supply fets out of circuit then re-check the drivers for the power supply fets..
Heres a pic of the drivers (red arrows pointing to them) but make sure you remove the bad fets before you test
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What part numbers are you trying to cross and what are you trying to cross them to?
It appears that one of the positive rectifiers has failed. Replace both of them.
The part numbers for the drivers are on the schematic.
It appears that one of the positive rectifiers has failed. Replace both of them.
The part numbers for the drivers are on the schematic.
Well that explains why I couldn't find them, wasn't looking at outputs, the schematic has the circuits separated out. I will desolder the bad fets and retest.
I didn't recognize that number as the outputs. And was concentrating only on the power supply stage of the amp and schematic. Thanks for your help and patience.
With the power supply fets removed the drivers still don't test correct so they are done.
Not sure what I should read on the darlington transistors but they are all consistent with each other (bank for bank that is) no open circuits but no shorts either. Around .5v -1.7v depending on lead position.
So the parts list so far is:
6 power supply fets
6 gate resistors
2 positive rectifiers
4 drivers
Anything else for the shopping list ?
Not sure what I should read on the darlington transistors but they are all consistent with each other (bank for bank that is) no open circuits but no shorts either. Around .5v -1.7v depending on lead position.
So the parts list so far is:
6 power supply fets
6 gate resistors
2 positive rectifiers
4 drivers
Anything else for the shopping list ?
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You may want to replace all of the rectifiers. SoundStream amps are known for being tough on rectifiers.
When you get all of the parts installed, clamp ALL transistors tightly to the sink and insert a 10-15 amp fuse in the B+ line. This will help protect the transistors if there is another problem.
When you get all of the parts installed, clamp ALL transistors tightly to the sink and insert a 10-15 amp fuse in the B+ line. This will help protect the transistors if there is another problem.
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