Sound board recapped and headers reflowed, still a loud hum. The volume, when cranked up all the way, is still pretty low too.
Maybe it's the volume pot? Can that cause both the hum and low volume?
(Topic ID: 252688)
Linked Games
Blackout
Williams, 1980
Topic Gallery
1 week later
I unplugged 10J4 and jumpered pins 1 & 2. Still have the hum. The volume was slightly higher for the in-game sounds, but not as loud as I would expect max volume to be.
All the sound board screws are in place. Would it be worthwhile to remove the board and sand the contact points between the back of the board and the backbox frame, just to ensure good contact? I reflowed all the headers when I did the cap kit. Is there something else I'm missing? I would love to get rid of this hum, it's my final issue.
Quoted from MaxAsh:I unplugged 10J4 and jumpered pins 1 & 2. Still have the hum. The volume was slightly higher for the in-game sounds, but not as loud as I would expect max volume to be.
All the sound board screws are in place. Would it be worthwhile to remove the board and sand the contact points between the back of the board and the backbox frame, just to ensure good contact? I reflowed all the headers when I did the cap kit. Is there something else I'm missing? I would love to get rid of this hum, it's my final issue.
Did you replace all the electrolytic caps on the sound board including the 1uf caps on the main sound board and the speech board?
Try adjusting the balance pot on the speech board. With the game off, move it across its entire range 5-10 times then leave it in the middle and test again. Sometimes if this pot gets dirty, you can experience low or scratchy volume. You use this pot to adjust the relative volume between sounds and speech callouts.
Quoted from Schwaggs:Did you replace all the electrolytic caps on the sound board including the 1uf caps on the main sound board and the speech board?
Try adjusting the balance pot on the speech board. With the game off, move it across its entire range 5-10 times then leave it in the middle and test again. Sometimes if this pot gets dirty, you can experience low or scratchy volume. You use this pot to adjust the relative volume between sounds and speech callouts.
I did all the caps on the main sound board, including the 1uf ones (that's what the kit had). I didn't have any caps for the speech board I don't think. Would that be it maybe? What if I disconnected the ribbon cable from the speech board, could I boot up that way and see if the hum is gone, to try and isolate the problem?
I've adjusted the balance pot before and it didn't change the problem, but I haven't tried the 5-10 times thing. I'll do that. Let me know if I can try isolating the speech board. I don't want to try it if that would be a bad idea.
Quoted from MaxAsh:I did all the caps on the main sound board, including the 1uf ones (that's what the kit had). I didn't have any caps for the speech board I don't think. Would that be it maybe? What if I disconnected the ribbon cable from the speech board, could I boot up that way and see if the hum is gone, to try and isolate the problem?
I've adjusted the balance pot before and it didn't change the problem, but I haven't tried the 5-10 times thing. I'll do that. Let me know if I can try isolating the speech board. I don't want to try it if that would be a bad idea.
You can definitely unplug the speech board interconnect cable. There is a jumper setting that may need to be changed also or you may experience no sound at all, maybe not I am unsure.
Quoted from swillie:You can definitely unplug the speech board interconnect cable. There is a jumper setting that may need to be changed also or you may experience no sound at all, maybe not I am unsure.
Disconnecting the speech cable from the main sound board eliminates the hum (and other sounds drop to a whisper, probably because of the dip switch setting you mentioned). I tried moving the balance pot back and forth several times, didn't affect the hum.
Is it safe to assume that means the hum issue is on the speech board? I didn't know I would have to recap that (kit didn't include anything for it).
Quoted from MaxAsh:Disconnecting the speech cable from the main sound board eliminates the hum (and other sounds drop to a whisper, probably because of the dip switch setting you mentioned). I tried moving the balance pot back and forth several times, didn't affect the hum.
Is it safe to assume that means the hum issue is on the speech board? I didn't know I would have to recap that (kit didn't include anything for it).
C12 10uf 20v is in the sound path on the speech board and should be replaced.
Does moving the balance pot with the game on result in scratchy audio? Does it change the balance?
If you jumper J1 on the main sound board you will eliminate the speech board from the circuit. You will only get sounds, not speech in this config. If you want to try it, I would replace C12 before spending time on this.
Some info on this link might be of use in setting the jumpers/switches properly...for with speech board and without.
Quoted from Schwaggs:C12 10uf 20v is in the sound path on the speech board and should be replaced.
Does moving the balance pot with the game on result in scratchy audio? Does it change the balance?
If you jumper J1 on the main sound board you will eliminate the speech board from the circuit. You will only get sounds, not speech in this config. If you want to try it, I would replace C12 before spending time on this.
Moving the balance with the game on does not result in any scratchy audio. The pot seems to work great, adjusting the balance of speech/sound as it should.
When you say jumper J1, I'm not sure what you mean. 10J1 on the main sound board is the power connector. I know there's a jumper called "W1" that's there, and I know it's supposed to be removed on games without speech. Not sure if you're referring to that or not?
I'll check to see if I have a cap for C12...
I'll probably need to order it.Found a 10uf 50V one in my container of capacitors, I'll go try replacing it and report back.
Grass Valley, CA
I had a hum once and had to replace the volume knob and wires leading to it that extends to the board. 15 bucks. Also check your speaker and connection wires. Maybe switch positive and negative wires, not sure if that will do anything.
Da-Shaker Unplugging the volume control wire completely (and jumpering pins 1&2 for max volume) doesn't get rid of the hum, so I don't think it's the volume pot or wiring, unfortunately. I checked the speaker and the wires were soldered on (looked original). I reflowed them, no change. Since unplugging the speech board from the setup eliminates the hum, guessing it's somewhere in that area.
Schwaggs Replaced C12 on the Speech board, no change sadly. Please let me know what you wanted me to try next, not sure what you meant on the jumpering idea. Thanks
Have you ever tried isolating the sound board from the brackets it's attached to in case it's a ground loop?
(old trick from car audio days)
Quoted from slochar:Have you ever tried isolating the sound board from the brackets it's attached to in case it's a ground loop?
(old trick from car audio days)
Not sure what you mean... you mean unscrewing it from the bracket entirely? Not sure that's a good idea, normally the lack of good connection is part of the issue. But I'll fully admit to being a novice in the realm of sound hum troubleshooting.
Isolate it from the bracket - people have used plastic washers and screws to do this, or plastic standoffs. The ground is still solid through your connector. The goal is to eliminate a differential in resistance between the connector ground and the metal bracket/backplane - in theory, they should always be the same, but in practice, small differences could contribute to hum.
Quoted from MaxAsh:trk12fire Unplugging the volume control wire completely (and jumpering pins 1&2 for max volume) doesn't get rid of the hum, so I don't think it's the volume pot or wiring, unfortunately. I checked the speaker and the wires were soldered on (looked original). I reflowed them, no change. Since unplugging the speech board from the setup eliminates the hum, guessing it's somewhere in that area.
schwaggs Replaced C12 on the Speech board, no change sadly. Please let me know what you wanted me to try next, not sure what you meant on the jumpering idea. Thanks
Well nuts, thought the cap would have helped.
You are right, the jumper is W1. It should be removed on games WITH speech (it should be out on your board). If you jumper that, disconnect the speech board you should get full volume game sounds if the problem is on the speech board.
Did you measure the power supply levels on the main sound board? You should have a +12V unregulated (12 to 14ish), -12V unregulated (-12 to -15ish) and a +5v regulated (should be right at 5v). Measure these on the sound board as it has it's own power supply different from the rest of the game.
Quoted from Schwaggs:Well nuts, thought the cap would have helped.
You are right, the jumper is W1. It should be removed on games WITH speech (it should be out on your board). If you jumper that, disconnect the speech board you should get full volume game sounds if the problem is on the speech board.
slochar I tried your idea, isolated it from the bracket, no change.
Sidenote: I did notice that when I turn down the cabinet volume low enough, the hum is much quieter. Of course then I can't hear the sounds either, but at least I know the hum seems to decrease with volume control
SchwaggsThis test worked exactly as you described. I disconnected the speech board ribbon cable, and jumpered W1. I turned the game on and there was
NOhum at all, and the sounds came out perfectly clear (and the volume was much louder as it should be). I was able to control the volume with the knob in the cabinet, and everything sounded great.
Clearly my issue is somewhere either on the Speech board (or perhaps the ribbon cable?). What's the next step now that we're isolated the issue?
Quoted from MaxAsh:Clearly my issue is somewhere either on the Speech board (or perhaps the ribbon cable?). What's the next step now that we're isolated the issue?
Get it fixed !!! 
Quoted from Da-Shaker:Ribbon cables are a cheap and easy fix. They're known to go bad from time to time. It's not a bad thing to swap out if your not sure.
The only issue with that is this 40-pin ribbon cable is soldered on the speech board side. Sadly not easy, and potential for me to make things worse, ha. That would probably be the last thing I consider, if replacing other components would be possible fixes. Knowing that the hum is only present when the Speech board is connected, and is the same hum whether I have the board screwed down to the frame or not, makes me wonder what else it could be with C12 already replaced?
If I'm not mistaken, the top of the ribbon connector that's soldered to the board can be pried off, allowing you to remove the ribbon cable and place a new one down. The top of the cable housing that had been removed will press the ribbon down into the barbs on the bottom half of the connector when placed back on. At least that's how it was on a BK i was working on a while back.
Quoted from frunch:If I'm not mistaken, the top of the ribbon connector that's soldered to the board can be pried off, allowing you to remove the ribbon cable and place a new one down. The top of the cable housing that had been removed will press the ribbon down into the barbs on the bottom half of the connector when placed back on. At least that's how it was on a BK i was working on a while back.
Hmm interesting, I thought it needed to be soldered. I see Andrew barakandl commented on that after some searching through other threads. Sounds like it can be tricky, but it's doable as you noted.
Do you think that's likely the issue? Wondering if I should try other things first.
Hey Max,
Fyi- There are more experienced people on your forum than myself. I'm just trying to help you out a little. I'm not good at testing boards. I usually reflow the back of the board and look for simple fixes. Sometimes I'll replace a capasitor or resistor and usually get lucky.
Quoted from Da-Shaker:Hey Max,
Fyi- There are more experienced people on your forum than myself. I'm just trying to help you out a little. I'm not good at testing boards. I usually reflow the back of the board and look for simple fixes. Sometimes I'll replace a capasitor or resistor and usually get lucky.
I really appreciate the help and suggestions from everyone, no worries. I'm in a similar boat as you, and do the same things you do. I usually track down as much as I can either on the forums, or in the schematics, and try things out. Eventually I get stumped (like now), and I turn to the folks on here with more experience any knowledge 
Interesting progress!
The sound and speech board uses separate power and ground bus for running analog components and digital components. Both supplies are derived by the same power supply on the main sound board but they are separated at output of the power supply section to avoid the noise of the digital components from making it into the audio stream. One possible cause might be a bad connection between the main and speech boards on the analog power supply.
Remove W1 and reconnect the speech board.
Turn the game on and measure the following voltage levels:
Main sound board:
One probe on the ground braid and the other on negative lead of C27 (the biggest cap) - This should be very close to zero
One probe on the negative lead of C27 and the other on the positive side of C27 - should be 12 to 14V
One probe on the negative lead of C27 and the other on the positive side of C25 - should be 5V
One probe on the negative lead of C27 and the other on the negative side of C26 - should be -12 to 14V
On the voice board:
One probe on the negative lead of C27 on the main sound board and the other on pin 8 of IC1 on the voice board - this should be very close to zero
One probe on the negative lead of C27 on the main sound board and the other on pin 16 of IC1 on the voice board - this should be very close to 5V
One probe on the negative lead of C27 on the main sound board and the other on pin 4 of IC2 or IC3 on the voice board - this should be very close to -12V
One probe on the negative lead of C27 on the main sound board and the other on pin 12 of one of the ROM chips on the voice board - this should be very close to zero
One probe on the negative lead of C27 on the main sound board and the other on pin 24 of one of the ROM chips on the voice board - this should be very close to 5V
Quoted from Schwaggs:Interesting progress!
The sound and speech board uses separate power and ground bus for running analog components and digital components. Both supplies are derived by the same power supply on the main sound board but they are separated at output of the power supply section to avoid the noise of the digital components from making it into the audio stream. One possible cause might be a bad connection between the main and speech boards on the analog power supply.
Remove W1 and reconnect the speech board.
Turn the game on and measure the following voltage levels:
Main sound board:
One probe on the ground braid and the other on negative lead of C27 (the biggest cap) - This should be very close to zero
One probe on the negative lead of C27 and the other on the positive side of C27 - should be 12 to 14V
One probe on the negative lead of C27 and the other on the positive side of C25 - should be 5V
One probe on the negative lead of C27 and the other on the negative side of C26 - should be -12 to 14V
On the voice board:
One probe on the negative lead of C27 on the main sound board and the other on pin 8 of IC1 on the voice board - this should be very close to zero
One probe on the negative lead of C27 on the main sound board and the other on pin 16 of IC1 on the voice board - this should be very close to 5V
One probe on the negative lead of C27 on the main sound board and the other on pin 4 of IC2 or IC3 on the voice board - this should be very close to -12V
One probe on the negative lead of C27 on the main sound board and the other on pin 12 of one of the ROM chips on the voice board - this should be very close to zero
One probe on the negative lead of C27 on the main sound board and the other on pin 24 of one of the ROM chips on the voice board - this should be very close to 5V
Schwaggs So I went through the list, and I ran into a couple of discrepancies. Could you clarify when you have a moment?
IC1 on the Speech board is a 14-pin chip. In your test suggestions, you have be testing pin 16 on IC1, which doesn't exist. You also asked me to test Pin 8, which appears to be Ground (GND). Not sure if that's what you wanted, so I thought I'd double-check.
Here are the results from everything I was able to test. I highlighted things outside of the ranges you stated in bold
Main sound board:
Ground braid to NEG lead of C27 = 0 VDC
NEG (-) lead of C27 to POS (+) lead C27 =
11.79 VDC
NEG lead of C27 to POS lead C25 = 4.91 VDC
NEG lead of C27 to NEG lead C26 = -13.33 VDC
On the voice board:
NEG lead of C27 main sound board to pin 8 of IC1 on the voice board = 0 VDC
(pin 8 is Ground)
NEG lead of C27 main sound board to pin 16 of IC1 on the voice board =
Pin 16 does not exist
NEG lead of C27 main sound board to pin 4 of IC2 or IC3 on the voice board = -13.33 VDC
NEG lead of C27 main sound board to pin 12 of one of the ROM chips on the voice board = 0 VDC (on all ROM chips)
NEG lead of C27 main sound board to pin 24 of one of the ROM chips on the voice board =
2.46 VDC(on all ROM chips)
IC1_Speech_Schem (resized).jpg
Quoted from MaxAsh:schwaggs So I went through the list, and I ran into a couple of discrepancies. Could you clarify when you have a moment?
IC1 on the Speech board is a 14-pin chip. In your test suggestions, you have be testing pin 16 on IC1, which doesn't exist. You also asked me to test Pin 8, which appears to be Ground (GND). Not sure if that's what you wanted, so I thought I'd double-check.
Here are the results from everything I was able to test. I highlighted things outside of the ranges you stated in
bold
Main sound board:
Ground braid to NEG lead of C27 = 0 VDC
NEG (-) lead of C27 to POS (+) lead C27 =
11.79 VDC
NEG lead of C27 to POS lead C25 = 4.91 VDC
NEG lead of C27 to NEG lead C26 = -13.33 VDC
On the voice board:
NEG lead of C27 main sound board to pin 8 of IC1 on the voice board = 0 VDC
(pin 8 is Ground)
NEG lead of C27 main sound board to pin 16 of IC1 on the voice board =
Pin 16 does not exist
NEG lead of C27 main sound board to pin 4 of IC2 or IC3 on the voice board = -13.33 VDC
NEG lead of C27 main sound board to pin 12 of one of the ROM chips on the voice board = 0 VDC (on all ROM chips)
NEG lead of C27 main sound board to pin 24 of one of the ROM chips on the voice board =
2.46 VDC(on all ROM chips)
[quoted image]
Interesting - your System 6 schematic is different than mine. IC1 is listed as a 16 pin chip on mine.... In any event... 
Measure from ground to pin 8 of either IC2 or IC3. This should be close to 5V and is the Analog 5V supply.
2.46v on the ROM chips pin 24 is not good. It should be close to 5V. Are you getting all the correct voices out of the board, even if they are very quiet? Are any of the ROM chips getting warm? Can you check for any bent pins that might be shorting?
Can you try removing all the roms from the voice board, starting the game and seeing of the hum is still there? Also, measure pin 24 of the empty socket to see if it is closer to 5V with the ROMs removed? Add one ROM at a time back to the board (with the game off please) and see when the voltage drops?
It seems either one of these ROMS is drawing too much power or the digital power pins in the ribbon cable is not making a good connection.
Quoted from Schwaggs:Interesting - your System 6 schematic is different than mine. IC1 is listed as a 16 pin chip on mine.... In any event...
Measure from ground to pin 8 of either IC2 or IC3. This should be close to 5V and is the Analog 5V supply.
2.46v on the ROM chips pin 24 is not good. It should be close to 5V. Are you getting all the correct voices out of the board, even if they are very quiet? Are any of the ROM chips getting warm? Can you check for any bent pins that might be shorting?
Can you try removing all the roms from the voice board, starting the game and seeing of the hum is still there? Also, measure pin 24 of the empty socket to see if it is closer to 5V with the ROMs removed? Add one ROM at a time back to the board (with the game off please) and see when the voltage drops?
It seems either one of these ROMS is drawing too much power or the digital power pins in the ribbon cable is not making a good connection.
Pin 8 on IC2 and IC3 = 4.94 VDC
I re-measured Pin 24 of the ROM chips (including the empty socket) and they're all showing 4.91 VDC now. Maybe I screwed something up before?
Hum is still there. I'll go try pulling each ROM chip (with the game off) and check for the hum as I go.
To answer the voice question - yes as far as I can tell, I'm hearing all the words properly.
OK, those voltages sound better - no need to try pulling ROM chips.
Can you list out all the capacitors (by cap number on the schematic) you have replaced?
Quoted from Schwaggs:OK, those voltages sound better - no need to try pulling ROM chips.
Can you list out all the capacitors (by cap number on the schematic) you have replaced?
Sure, and I'll include pics from the schematics with blue dots on the ones I did, for reference. If you need the values, let me know.
Sound Board capacitors replaced: C14, C15, C25, C26, C27 also C12, C30, C36
Speech Board capacitor replaced: C12
Blackout_Sound_Schem (resized).jpgBlackout_Speech_Schem (resized).jpgTry replacing C29 - 10uf 25V
That is another capacitor in the audio path that should have been in your cap kit.
Quoted from Schwaggs:Try replacing C29 - 10uf 25V
That is another capacitor in the audio path that should have been in your cap kit.
C29 replaced... no luck. I really appreciate you sticking with this and trying to help with the mystery @schwaggs . Hopefully we can track it down!
Quoted from MaxAsh:C29 replaced... no luck. I really appreciate you sticking with this and trying to help with the mystery @schwaggs . Hopefully we can track it down!
Nuts.
So you have good voltage and ground readings on the speech board.
Nothing changes when you remove the boards from the backbox mounts (floating the boards)
All the electrolytic caps have been replaced.
The hum goes away when the speech board is not in the circuit. (problem must be on the speech board)
This covers all the common failure points. Lets dig a little deeper and see if you can find the point where the hum is generated.
Put your meter on AC. One lead on ground. With the game idle (not playing any sounds, just humming), measure the voltage at the following spots:
Negative side of C29 on the main board - this is analog audio out
IC3 pin 1 on the speech board - speech filter stage
IC3 pin 7 on the speech board - speech filter stage
IC2 pin 7 on the speech board - analog and speech mixer output
Also, have a look at C1 on the speech board. Has it been replaced or worked on in the past? It is a tantalum capacitor from the factory. They usually last forever and very rarely fail but it can happen.
Have you checked the bridge rectifier? I don't think bridges just go bad as often as people think but I have had to replace one before on one of these sound boards. If a diode in it opened up then it will only end up being a half wave by bridge and you will probably get more hum.
Quoted from Robotworkshop:Have you checked the bridge rectifier? I don't think bridges just go bad as often as people think but I have had to replace one before on one of these sound boards. If a diode in it opened up then it will only end up being a half wave by bridge and you will probably get more hum.
I thought of that too. However when the speech board isn't connected, the board works perfectly so I skipped that. It still might be the problem but I think it is a remote chance...
Quoted from Schwaggs:Nuts.
Put your meter on AC. One lead on ground. With the game idle (not playing any sounds, just humming), measure the voltage at the following spots:
Negative side of C29 on the main board - this is analog audio out
IC3 pin 1 on the speech board - speech filter stage
IC3 pin 7 on the speech board - speech filter stage
IC2 pin 7 on the speech board - analog and speech mixer output
Also, have a look at C1 on the speech board. Has it been replaced or worked on in the past? It is a tantalum capacitor from the factory. They usually last forever and very rarely fail but it can happen.
Including a pic of C1 on the Speech board, looks original.
Here are the results of testing (game on, attract mode, no sound just the humming):
Negative side of C29 on the main board - this is analog audio out = 0 VAC
IC3 pin 1 on the speech board - speech filter stage = 0 VAC
IC3 pin 7 on the speech board - speech filter stage = 0 VAC
IC2 pin 7 on the speech board - analog and speech mixer output = 0VAC
Blackout_Speech_C1 (resized).jpgQuoted from MaxAsh:Including a pic of C1 on the Speech board, looks original.
Here are the results of testing (game on, attract mode, no sound just the humming):
Negative side of C29 on the main board - this is analog audio out = 0 VAC
IC3 pin 1 on the speech board - speech filter stage = 0 VAC
IC3 pin 7 on the speech board - speech filter stage = 0 VAC
IC2 pin 7 on the speech board - analog and speech mixer output = 0VAC[quoted image]
It does look original.
None of those readings are pointing to a problem. I only have guesses left on what the problem might be.
1) Tantalum capacitor C1
2) IC2 and IC3 on the speech board
3) Replace BR1 on the main sound board as Robotworkshop suggested
Anyone else watching along have suggestions?
Quoted from MaxAsh:schwaggsThis test worked exactly as you described. I disconnected the speech board ribbon cable, and jumpered W1. I turned the game on and there was NOhum at all, and the sounds came out perfectly clear (and the volume was much louder as it should be). I was able to control the volume with the knob in the cabinet, and everything sounded great.
Remember this Just a reminder from the past. You have done a lot of work. You have to figure this out. Keep it up. 
Quoted from MaxAsh:Clearly my issue is somewhere either on the Speech board (or perhaps the ribbon cable?).
Did we ever replace ribbon cable?
Did you just add solder when you reflowed the header pins for the connectors or did you clean out the old solder first?
Whenever I rebuild those boards I remove those connectors and clean the oxidation off the connectors where they are soldered. They can get heavily oxidized when the solder joints are cracked. If you just try to reflow it it tough to get a proper connection.
You may still have bad connections for the grounds throughout the game as well.
Quoted from bssbllr:Remember this Just a reminder from the past. You have done a lot of work. You have to figure this out. Keep it up.
Did we ever replace ribbon cable?
If the sound card works and speech is ok I don't think the ribbon cable would be bad. Maybe I've just been lucky but I haven't had to replace one yet and I've fixed a bunch of these sound/speech boards.
Quoted from Robotworkshop:If the sound card works and speech is ok I don't think the ribbon cable would be bad. Maybe I've just been lucky but I haven't had to replace one yet and I've fixed a bunch of these sound/speech boards.
I didn't replace the ribbon cable yet. As for the headers, since the hum goes away when I unplug the ribbon cable (removing speech board connectivity but leaving sound fully functional and significantly louder), I'm guessing the headers aren't the issue, correct? There are no headers on the speech board aside from the ribbon cable connection, so I think I'm okay from that perspective.
Does the ribbon cable factor into a possible ground or hum issue normally? Clearly unplugging it removes the hum. Given the somewhat tricky nature of replacing it, I haven't touched it in anyway. I read about prying it up in one of the guides, and I'm a little concerned I'll make things worse.
I could do some videos, if it's helpful, just to demonstrate the issues.
Quoted from MaxAsh:I didn't replace the ribbon cable yet. As for the headers, since the hum goes away when I unplug the ribbon cable (removing speech board connectivity but leaving sound fully functional and significantly louder), I'm guessing the headers aren't the issue, correct? There are no headers on the speech board aside from the ribbon cable connection, so I think I'm okay from that perspective.
Does the ribbon cable factor into a possible ground or hum issue normally? Clearly unplugging it removes the hum. Given the somewhat tricky nature of replacing it, I haven't touched it in anyway. I read about prying it up in one of the guides, and I'm a little concerned I'll make things worse.
I could do some videos, if it's helpful, just to demonstrate the issues.
Sorry, I should have been more clear. Meant the larger .156 connectors where everything attaches to the board at the top.
Is there someone in the area with a Blackout game you can try running your boards in? That would help to confirm the issues are really on your boards or not.
Quoted from Robotworkshop:Sorry, I should have been more clear. Meant the larger .156 connectors where everything attaches to the board at the top.
Is there someone in the area with a Blackout game you can try running your boards in? That would help to confirm the issues are really on your boards or not.
I knew which ones you meant , but those connectors are all on the main sound board, and since the hum vanishes when the Speech board is disconnected, but main board still hooked up to all those connectors, I was saying that I doubt they would be the issue. Do you think that's still possible?
I've learned never to assume anything doing repairs. I'll have to take a look at the schematic again. If you have access to a scope it would be interesting to see if that can help pinpoint the issue.
Quoted from Robotworkshop:I've learned never to assume anything doing repairs. I'll have to take a look at the schematic again. If you have access to a scope it would be interesting to see if that can help pinpoint the issue.
Sadly no scope, just my meter.
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