Light sixer - No sound after cap refresh

[cpnbnanamn]

Hey all..  Been lurking here for a minute or two, and finally dug into the light sixer I picked up last year.  Initially, it had a good picture but the sound would drop off after a bit.  Did some reading here, and got the cap refresh kit from Console5, and replaced all of those including the VR, chiclet (C103), and the styrene caps.  Did the new IC chip (A203), after installing a socket there first.  Here's the issue:
No sound.  None.  Nada.  Tried tweaking L201 a little.  Nothing. 
I did notice that the 'ribbon cable' gets a little squirrely if you touch it, causing red or green screen, but if I don't screw with it, everything else is find (except, still no sound).  What have I missed?  I promise I did do some searching before I asked, but I am not getting a clear answer.  I'd really like to get this back up and running.  Wasn't planning on doing any kind of sound/video mod, as this was an original, in-the-original-box sixer.  Was trying to keep it as much stock as possible.  I'd really appreciate some help.

[Voxel]

To begin with I'd check the soldering for continuity with a meter and make sure all the contacts are good (connector lead, switches, ground contacts etc).

 

Then I'd follow through the audio circuit from the chip to the RF.

 

It sounds like a nice console, so persevere and take your time and be methodical.

[christo930]

On 12/18/2020 at 9:23 PM, cpnbnanamn said:

Hey all..  Been lurking here for a minute or two, and finally dug into the light sixer I picked up last year.  Initially, it had a good picture but the sound would drop off after a bit.  Did some reading here, and got the cap refresh kit from Console5, and replaced all of those including the VR, chiclet (C103), and the styrene caps.  Did the new IC chip (A203), after installing a socket there first.  Here's the issue:
No sound.  None.  Nada.  Tried tweaking L201 a little.  Nothing. 
I did notice that the 'ribbon cable' gets a little squirrely if you touch it, causing red or green screen, but if I don't screw with it, everything else is find (except, still no sound).  What have I missed?  I promise I did do some searching before I asked, but I am not getting a clear answer.  I'd really like to get this back up and running.  Wasn't planning on doing any kind of sound/video mod, as this was an original, in-the-original-box sixer.  Was trying to keep it as much stock as possible.  I'd really appreciate some help.

The first thing I would do is download a test cartridge that will generate a tone and run it if you have that ability.  If not, I suppose you will have to find a game that you know is going to be generating sound.

Check on the (sound) source side side of the cap in the audio circuit. See if you have the sound there. Then check the other side of the cap. It could be an open cap.  If the sound worked before you replaced the cap, you probably either have a dead cap or you made some sort of mistake.  I would also double check the socket you installed (not having any idea what it is having not looked at schematics).  Find the source of the sound and start probing.  See where you lose the sound assuming you have it in the first place. 

 

Go back and double check your work. Use a magnifying glass in a well lit area and take your time.  Carefully examine everything you did.   The ribbon cable getting "squirrely" is not a good sign that all is well.  Keep a lookout for frayed wired at the ends where you have them going into through-holes on the board or otherwise connected to something.  Also, you should probably do this part first. You don't want to burn anything out.  It's also not a bad idea to just go over the whole board in this way and make sure you didn't accidentally drop solder blobs anywhere or otherwise accidentally cause problems in areas where you weren't working but which were necessarily exposed while you were doing the work.

 

 

[+-^CrossBow^-]

For a game that immediately plays sounds, you want a copy of Frogger.

 

[cpnbnanamn]

On 12/27/2020 at 10:31 PM, christo930 said:

The first thing I would do is download a test cartridge that will generate a tone and run it if you have that ability.  If not, I suppose you will have to find a game that you know is going to be generating sound.

Check on the (sound) source side side of the cap in the audio circuit. See if you have the sound there. Then check the other side of the cap. It could be an open cap.  If the sound worked before you replaced the cap, you probably either have a dead cap or you made some sort of mistake.  I would also double check the socket you installed (not having any idea what it is having not looked at schematics).  Find the source of the sound and start probing.  See where you lose the sound assuming you have it in the first place. 

 

Go back and double check your work. Use a magnifying glass in a well lit area and take your time.  Carefully examine everything you did.   The ribbon cable getting "squirrely" is not a good sign that all is well.  Keep a lookout for frayed wired at the ends where you have them going into through-holes on the board or otherwise connected to something.  Also, you should probably do this part first. You don't want to burn anything out.  It's also not a bad idea to just go over the whole board in this way and make sure you didn't accidentally drop solder blobs anywhere or otherwise accidentally cause problems in areas where you weren't working but which were necessarily exposed while you were doing the work.

--------------------------------------------------------------------------

 

So I did go over everything, and after tweaking a bit, I got my sound back!!  BUT.........  It's odd. At first, the sound was really noisy, and unusable.  Then, after sleeping on it a bit, I kinda figured it out.  I had to adjust L201 a LOT the other way to get the correct sound back.  It's working - mostly.  I'll play with it for a bit, and it'll work, but then if I turn it off and come back to it later, the sound will work, and then slowly fade, although not completely out.  Weird! 
Regarding the cartridge I used - I had a copy of Raiders of the Lost Ark, and that plays continuous sound.  I didn't know you could download a test cartridge??

And my solder work, is exemplary, if I do say so myself.  LOL  No dropped blobs here!  LMAO

I AM kinda wondering if either the TIA chip is failing/fading or of doing a UAV mod would level this out.  Picture is good, but a get a good bit of ghosting, too.  Not as sharp as I've seen from other users.

 

[christo930]

On 1/8/2021 at 2:31 PM, cpnbnanamn said:

 

 

As the sound fades, go around to components in the audio circuit and use some canned air upside down to cool down the component.  Also, if you have the ability, just point a thermal camera at it while it's running the game and look for hotter components and try the freeze spray on them.

 

As to the screen quality, the very first thing I would do is spray down the switches with deoxit or other contact cleaner, especially the channel select switch.  I had all kinds of screen quality problems with most of my Ataris and that solved it. Colecovisions are rather infamous for the power switch doing similar and more awful things. The switches in the Atari are the same design as the on/off switch in the Colecovision.

 

If you have some powered speakers that you don't care about, you can use them to trace the sound.  Take one channel input of the powered speaker and put it to ground on the atari and attach a capacitor to the other lead to that side (negative towards the amp if you are using a polarized cap) and then use the other lead of the capacitor as a probe.  The capacitor is not absolutely necessary, but it will keep you from putting DC into your speaker input.  You need to trace the sound from the source and then see where you lose it. Having never examined the schematic, I assume it goes through a transistor and that is the most likely place it is going to have this problem (sound getting lower after being on a little while) or possibly an op amp.  Again, make sure all your work is correct.

[chewy]

oh god. are you guys gonna rip me for having a working survivor non-recapped light sixer instead of immediately going in a ripping all the caps out and watching a youtube video to learn to solder new ones in.  Cause thats what the vintage TV forum is like, lol.  

[cpnbnanamn]

On 1/10/2021 at 12:41 PM, chewy said:

oh god. are you guys gonna rip me for having a working survivor non-recapped light sixer instead of immediately going in a ripping all the caps out and watching a youtube video to learn to solder new ones in.  Cause thats what the vintage TV forum is like, lol.  

Nothing like that, man.  My light-sixer is old, and needs help.  I'm doing what I can.  Just frustrated.  I love this damn thing.

[cpnbnanamn]

On 1/10/2021 at 12:27 AM, christo930 said:

 

As the sound fades, go around to components in the audio circuit and use some canned air upside down to cool down the component.  Also, if you have the ability, just point a thermal camera at it while it's running the game and look for hotter components and try the freeze spray on them.

 

As to the screen quality, the very first thing I would do is spray down the switches with deoxit or other contact cleaner, especially the channel select switch.  I had all kinds of screen quality problems with most of my Ataris and that solved it. Colecovisions are rather infamous for the power switch doing similar and more awful things. The switches in the Atari are the same design as the on/off switch in the Colecovision.

 

If you have some powered speakers that you don't care about, you can use them to trace the sound.  Take one channel input of the powered speaker and put it to ground on the atari and attach a capacitor to the other lead to that side (negative towards the amp if you are using a polarized cap) and then use the other lead of the capacitor as a probe.  The capacitor is not absolutely necessary, but it will keep you from putting DC into your speaker input.  You need to trace the sound from the source and then see where you lose it. Having never examined the schematic, I assume it goes through a transistor and that is the most likely place it is going to have this problem (sound getting lower after being on a little while) or possibly an op amp.  Again, make sure all your work is correct.

 

[cpnbnanamn]

Good thoughts, and I've done about all of that, including cleaning all of the switches.  I've got a brewery kit en route. 

Right now, my frustration is with the sound.  While is SOOO much better than it was, I can figure out why it keeps fading out.

Here's what I noticed this evening: 
Turned it on after not having it on for a couple of days.  Sound was GREAT....... for about 3-5 minutes.  While playing Donkey Kong, I heard it fading, but it never fades completely.  I put in Raiders, and it's the same thing.  Tweak L201, and it's solid.  So, I turn it off, unplug it, and go back to it after a few.  Same thing.  Good sound for 3-5 minutes, and then slowly fades.
Like I said, never fully dies off anymore, but I can't keep the level up.  I've had to leave the cover off just so I can tweak L201 constantly.

 

[chewy]

19 hours ago, cpnbnanamn said:

Nothing like that, man.  My light-sixer is old, and needs help.  I'm doing what I can.  Just frustrated.  I love this damn thing.

thats cool you are taking it on its also good to know that there are many left in the world in case you ever need another.  When my 1930 radio busted a resistor, i was absoutely freakin', and I mean freakin'.  

[+DrVenkman]

On 1/11/2021 at 6:29 PM, cpnbnanamn said:

I've had to leave the cover off just so I can tweak L201 constantly.

You should realistically NEVER have to change an inductor coil like that once set at the factory, if everything else is okay. It's quite possible at this point you have a damaged inductor. You could try replacing it, or - since you're already doing an unnecessary cap job - just install a UAV and take audio straight from TIA. 

[christo930]

On 1/11/2021 at 7:29 PM, cpnbnanamn said:

Good thoughts, and I've done about all of that, including cleaning all of the switches.  I've got a brewery kit en route. 

Right now, my frustration is with the sound.  While is SOOO much better than it was, I can figure out why it keeps fading out.

Here's what I noticed this evening: 
Turned it on after not having it on for a couple of days.  Sound was GREAT....... for about 3-5 minutes.  While playing Donkey Kong, I heard it fading, but it never fades completely.  I put in Raiders, and it's the same thing.  Tweak L201, and it's solid.  So, I turn it off, unplug it, and go back to it after a few.  Same thing.  Good sound for 3-5 minutes, and then slowly fades.
Like I said, never fully dies off anymore, but I can't keep the level up.  I've had to leave the cover off just so I can tweak L201 constantly.

 

Have you 100% ruled out the TV and connection to the TV? 

 

The only suggestion I have left is when the volume starts dropping is hit components in the audio circuit with upside down canned air.

You should not need to continuously tweak things.

Have you tried tracing the audio?  Did you find out where it is dropping off?

[cpnbnanamn]

10 hours ago, christo930 said:

Have you 100% ruled out the TV and connection to the TV? 

 

The only suggestion I have left is when the volume starts dropping is hit components in the audio circuit with upside down canned air.

You should not need to continuously tweak things.

Have you tried tracing the audio?  Did you find out where it is dropping off?

I have traced back to pins 12&13 in the TIA IC, and I hear audio there.  Doesn't sound like it's dropping off, but it's hard to tell with such weak output.  At this point, aside from the inductors, the IC, and RF Module, I've replaced everything else in the oscillator circuit, and it persists. I've considered the possibility that the slug in the inductor has deteriorated, and I'm using a plastic adjustment tool to tweak.

[cpnbnanamn]

On 1/12/2021 at 9:06 PM, DrVenkman said:

You should realistically NEVER have to change an inductor coil like that once set at the factory, if everything else is okay. It's quite possible at this point you have a damaged inductor. You could try replacing it, or - since you're already doing an unnecessary cap job - just install a UAV and take audio straight from TIA. 

You're right, I shouldn't have had to.  But in going ti MLCC caps vvs the poly's that were in there, some tuning is necessary.  I even consulted with an analog engineer buddy of mine to confirm the same.
  And as far as the UAV kit - I have one en route from Brewery academy as we speak.  I'm PRAYING that solves my issue.

[cpnbnanamn]

So, the UAV will not solve an audio issue, I've learned.  I'm still tinkering, and I'm thinking that TBA's IAB may solve it.  Either that, or attempt to replace L201.  I just find it odd that it needs tweaking when cold.  I've replaced the oscillator caps and transistor.  There's not much else.

[+DrVenkman]

Look, your first post claims you want to keep the machine stock, but you'd already replaced all the caps, so in for a penny, in for a pound. You don't need any kind of add-on board to add sound to an A/V mod. Just trace out the schematics from TIA's two audio pins to the next-nearest components (generally, a resistor). Solder in your audio pickup from those audio lines, tied together unless you're wiring up stereo output. But since hardly any 2600 games have stereo audio, most people just do mono or dual-mono outputs.