I have a Sorcerer that was playing all of it's sounds fine when I first picked her up. I started a post last month on trying to fix the flippers but thought this issue needed it's own topic. Here's a recap of the end of that thread: While trying to fix the flippers last month over the course of a couple of days the sound started to cut out and I started getting an error code 7 on the cpu. It was suggested that I twist the IC sockets after a couple of games and see if one of them locks up the game. I played a bunch of games and then twisted them all and the game locked up. Realizing I should have tried them 1 at a time I tried them again and found that U5 locked the game up. 1st I replaced U5's 6821 pia and game worked fine for a day then next day had an error code of 7 again. This time when I manipulated the U49 sound rom the game went back to a "0" diagnostic so I ordered a new set of game roms and re socketed and replaced U49. I also re socketed U19 and U20 game roms and added the new chips in them as well. Still the next day after playing fine with all sounds the game wouldn't boot with an error code 7 again.

I tried manipulating the sockets again and found U17 a 6808 brought the game back. I replaced the socket and found another 6808 and that fixed the error 7 code but the game didn't have sounds. I can't remember where I read it pinwiki or another pinside thread but it was suggested to swap the 6808 chips at U17 and U13. When I swapped them the 6808 that was by the sound section in U13 now locks the game up when its in U17's socket. I was out of 6808's but read that a 6802 was a drop in replacement and only needed to be jumpered if you were using the chip's internal ram. I placed the 6802 in U17 and now the game plays for days without locking up and I have clear speech but all other sounds are super low. In a game or in test mode through the door or the SW2 diagnostic on the board, you have to put your ear up to the speaker to barely hear them.

The cabinet pot works fine. I can hear the static change smoothly when I turn the knob. The dmm test with one lead on the middle lug and testing the other lugs while turning the knob reads smooth changing #s. I re crimped the wires running from the pot to IJ15 just in case with no luck. The pot on the speech board works fine as well. I then read to isolate the cpu from the speech board to test just the sounds by removing the ribbon connector between the 2 and place a jumper on W10 under the U12 6810 ram chip. When I test the sounds with this scenario they sound the same, super low.

I've tested the 5 pin 2002 audio amplifier at U47 by finding 13 volts on pin 5 and pin one produces a hum. I have tested the R77 resistor for the -12 volts and pin 3 on U48 has the -12 voltage as well. I have tested the Q51 transistor and have the same reading as all the others on the board 650 ohms on one leg and 900 on the other. I have tested pins 2 through 9 on the U13 6808 chip and they pulse from 0 to 4.85 volts when each sound is produced for that pin. I also read in another thread a pinsider solved his issue by replacing U12's 6810 ram chip. I re socketed and replaced that chip as well with the same results. Both the cpu board and the power supply board don't have any cracked solder joints especially at IJ15 and 17 and the 15 pin connector on the psb.

I removed the board to test the caps. C2 measures 600 ohms one way and the C7 cap is 650ohms with the leads reversed. C5 measures 280 ohms and 340 ohms, C24 under the U47 amplifier measure 1 and 1 but when I measure the positive lead traced to R73 I get a measurement of 278ohms. The last cap C53 measures 1.400ohms and 716 ohms.

The last component that I don't know how to test that I've read in other threads is the oscillator at U21. Any other advice on what I missed or which component I should suspect would be greatly appreciated.

Had 2 graduation parties this weekend and should have bumped this thread. I read that C7 should have been measured in vac and I don't have a 12 volt bench supply to test in circuit so I removed the board and replaced C7 and C24 with new caps. Unfortunately still all sounds are barely audible except for speech which works fine.

After looking at the schematics again I'm trying to rule out the components that are down stream from the W10 jumper. If the 40 pin connector at IJ20 that runs to the sound board is unplugged and the W10 jumper connected then everything in that section past the W10 that runs into IJ16 pin 1 and out of IJ16 pin2 to the speakers should be ok since it plays speech loud and clear through them when hooked up even though the rest of the sounds play but are barely audible.Sorcerer sound schematic (resized).jpg

Sorcerer sound schematic (resized).jpg

Thanks GPE for chiming in and taking the time. So the only way to test caps is with an oscilloscope then? I have a bunch of caps to look through to check if I have a 10uf cap and hopefully get my sounds back to normal.

Thought it was my lucky day because I had a 10 uf cap on hand. The original cap was rated for 20V and the one I had is for 50V but the uf# is the same. Soldered it in the proper direction and powered up and still can't hear the sounds just the speech. The IC chips associated with the sound section in the schematics are U11, U12, U13, U48, U49 and U50. The U11 6808 chip, U12 6810 chip, and U49 sound rom chip have all been socketed and replaced. This leaves the U13 6821 pia chip, U48 D/A converter and the U50 74LS138 line decoder chip. The Williams Sys 9 trouble shooting guide says that cap C31, transistor Q51 and U48 coverter rarely fail but I could be that lucky guy. I am getting pulses at U13 on pins 2-9 and the U48 converter's pin 3 has the -12V and some of the pins pulse between 0 and 3V. This leaves the U50 74LS138 line decoder chip. pin 1 is the 5V and pin 8 must be ground. Pins 2-7 measure 2-3V and pins 9-17 measure 4.3V. I don't have either of these chips on hand.Sorcerer IC sound chips (resized).png

bumping this post to see if anyone has an idea of how to get my Sorcerer sounds back to normal volume. I removed the board over the weekend and replaced the rest of the caps, (C2, C5, C7, C9, C24, C32 and C53,) with the same result of normal sounding speech but super low sounds. I have a friend who told me when having sound issues a number of times it was the audio amplifier at U47. When testing the amplifier,(ICTDA2002,) with the dmm I leave the neg lead under the ground strap in the head and receive 13V at pin 5 and get a hum in the speakers when I touch pin 1. At this point if both sound and speech are playing but only 1 of them getting amplified should I just replace the U47 amplifier even though it tests fine or should I suspect U48 D/A converter and the U50 74LS138 line decoder chip?

Thanks for chiming in grbgemen. I thought that checking for sounds on the cpu by disconnecting the 40 pin connector to the speechboard and pressing SW2 eliminated components like the op amps and others on the speech board. I assumed the pot on the speech board was for speech only so you could adjust it against the sounds if you felt the speech was too overpowering. I just checked it again and it will raise and lower the speech perfectly but if it's supposed to mix the sounds I guess I'll replace the 55536 chip I have at U1 on the speech board. I ordered some TDA2002s today so I'll check with my friend to see if he has the 55536 chip.

I received the components for U47 the amplifier, U48 the D/A converter and U50 the line decoder chip. I replaced them all one at a time and still Sorcerer's sounds elude me!! Anyone else have any idea what I should be looking at? Am I moving over to the speech board and checking the 55536 chip?

Thanks PINTEC, just saw this before going to bed but will try W10 again tomorrow. I tried it while isolating the speech board by unplugging the ribbon cable and jumping W10 and the sounds were the same, there but very low. I'll also bust out the dmm again and probe for shorted resistors.

Yes the W10 jumper is there to afford you the ability to hear the sounds separate from the speech board so I believe you're right. I just lost faith and am ready to try anything to make it work. I tried the jumper again today and the sounds are still too low to be heard. I have to check tomorrow morning because the game is in the living room and so is the wife...

I probed all the resistors and 2 of them R71 and R73 under the speech amplifier at U47 read .003 and tone open both ways. If anyone has a Sorcerer could you please check your R71 and R73 on the bottom right hand corner of the cpu and see if you get the same reading? I also measured all of the small "B" resistors in front of each IC chip and they all measure .204 one way and .190 the other, except the one before U18 ram IC 5571-2. That "B" resistor measures 1. and beeps open the other way. Does that mean U18 is compromised?

The R71 resistor from the bottom to top is Brown, Black, Gold and Gold and should be a 1 ohm 5% 1/2 Watt
The R73 resistor from the bottom to top is Gold, Gold, Red and Red and should be a 2.2 ohm 5% 1/4 Watt

Please ignore the R71 and R73 posts. My friend Dennis who has a Sorcerer was kind enough to check his R71 and R73, gave me his readings of 1.6 and 2.8 and pointed out I had my dmm set on continuity. Once probed properly I have the same readings. After reading note 5 in the manual for the cpu all of the bypass B capicitors before the IC chips are .01 mfd. I have 2 of these that have no resistance the one before U18 and one before U51.

Thanks PINTEC, I'm guessing the 6821 at U13 right above the DA chip. I haven't touched that one yet and it's is soldered directly to the board, I have to go find a socket.

Installed a new socket and 6821 at U13 and still the same result.

PINTECH YOU DA MAN! I removed the board and checked the address lines for the U48 D/A converter adn all were ok and not shorted to each other, The R77 has -13V on the top end and 1. on the other. I then moved to Q51 and swapped in a new 2N3904 NPN transistor and that did the trick. I put the board in fired her up and thanked the Lord for the guy in Chicago!! Thanks so much for taking the time to walk me through it!