VOGONS


Partially dead CT2700 (fixed!)

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First post, by trozx

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Same old story - bought a CT2700 from that auction site, and it only partially functions. Midi plays but no digital sound - sometimes a faint beeping can be heard or an occasional, garbled high pitch sound will come through when digital audio is played.

Main rig is a Socket 7, DOS 6.22 only machine.

* Jumpers match SET variable.
* Clean driver install in Dos 6.22.
* SBCHECK reports the card correctly.
* Triple checked for resource conflicts.
* Tried in a Win98 system- Pentium 3 / Slot 1 - same symptoms.

Does anybody have a schematic of this card? I think the DSP is good, but maybe a failed DAC.

No missing components. No shorts across the capacitors. I thought about a recap, but I don't know if it's worth fixing.

The music output is strong and clean, with or without the op amps enabled.

I have a wave blaster type card on the way, maybe I can use it just for music and use a PNP card for everything else.

Other suggestions?

Solved:

Solution here.

Last edited by trozx on 2021-11-25, 02:58. Edited 3 times in total.

Reply 1 of 25, by cyclone3d

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CT2700 is a first gen SB16 card and it comes up with almost no results in a google search.

See here for some possible fixes as it is almost the same as the CT1740 except for the DSP version and the CD controller:
Creative sound blaster 16 CT1740 very low sound

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 3 of 25, by cyclone3d

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georgel wrote on 2021-11-23, 05:22:

First try on another motherboard with Creative's DIAGNOSE utility and then make conclusions that you SB is faulty which I highly doubt.

OP stated they tried in in two different systems.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 4 of 25, by bloodem

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georgel wrote on 2021-11-23, 05:22:

First try on another motherboard with Creative's DIAGNOSE utility and then make conclusions that you SB is faulty which I highly doubt.

Why do you highly doubt? 😀
I've repaired quite a few damaged SB16s (with similar symptoms), which is why I'm asking.

2 x PGA132 / 5 x Socket 3 / 9 x Socket 7 / 12 x SS7 / 1 x Socket 8 / 14 x Slot 1 / 5 x Slot A
5 x Socket 370 / 8 x Socket A / 2 x Socket 478 / 2 x Socket 754 / 3 x Socket 939 / 4 x LGA775 / 1 x LGA1155
Current rig: Ryzen 5 3600X
Backup rig: Core i7 7700k

Reply 5 of 25, by georgel

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bloodem wrote on 2021-11-23, 06:15:

Why do you highly doubt? 😀
I've repaired quite a few damaged SB16s (with similar symptoms), which is why I'm asking.

If you had "repaired quite a few damaged SB16s " why are are more interested in my doubts than in helping the OP with their sound card in the first place?

Reply 6 of 25, by pshipkov

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I have the feeling this is the card you bought from me recently.
If that's the case - it worked fine 2-3 weeks ago, but looks like it's health deteriorated on the way to you.
I reimbursed you already, but still hope you manage to fix it.
Fingers crossed.

retro bits and bytes

Reply 7 of 25, by trozx

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pshipkov wrote on 2021-11-23, 09:40:
I have the feeling this is the card you bought from me recently. If that's the case - it worked fine 2-3 weeks ago, but looks li […]
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I have the feeling this is the card you bought from me recently.
If that's the case - it worked fine 2-3 weeks ago, but looks like it's health deteriorated on the way to you.
I reimbursed you already, but still hope you manage to fix it.
Fingers crossed.

Small world!

Well, old card, old solder, maybe some joints cracked during transit. It was in a static bag, so I doubt it was ESD. A reflow of the larger components wouldn't hurt.

Reply 8 of 25, by trozx

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bloodem wrote on 2021-11-23, 06:15:
georgel wrote on 2021-11-23, 05:22:

First try on another motherboard with Creative's DIAGNOSE utility and then make conclusions that you SB is faulty which I highly doubt.

Why do you highly doubt? 😀
I've repaired quite a few damaged SB16s (with similar symptoms), which is why I'm asking.

Not exactly the reply I was looking for. But, since you're here, can you list a few of the failure modes on your cards and the solutions? I do have a garage full of test equipment, less a logic analyzer.

Reply 9 of 25, by trozx

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georgel wrote on 2021-11-23, 05:22:

First try on another motherboard with Creative's DIAGNOSE utility and then make conclusions that you SB is faulty which I highly doubt.

Yes, I tried DIAGNOSE as well - the digital sounds test results in the same symptoms. It's definitely a bad card, not my first rodeo.

Reply 10 of 25, by georgel

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trozx wrote on 2021-11-23, 13:51:
georgel wrote on 2021-11-23, 05:22:

First try on another motherboard with Creative's DIAGNOSE utility and then make conclusions that you SB is faulty which I highly doubt.

Yes, I tried DIAGNOSE as well - the digital sounds test results in the same symptoms. It's definitely a bad card, not my first rodeo.

My instruction stresses on another motherboard and secondly with DIAGNOSE or whatever. Was it on the same motherboard?

Reply 11 of 25, by trozx

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georgel wrote on 2021-11-23, 14:06:
trozx wrote on 2021-11-23, 13:51:
georgel wrote on 2021-11-23, 05:22:

First try on another motherboard with Creative's DIAGNOSE utility and then make conclusions that you SB is faulty which I highly doubt.

Yes, I tried DIAGNOSE as well - the digital sounds test results in the same symptoms. It's definitely a bad card, not my first rodeo.

My instruction stresses on another motherboard and secondly with DIAGNOSE or whatever. Was it on the same motherboard?

Two different motherboards, same problem.

Reply 14 of 25, by bloodem

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trozx wrote on 2021-11-23, 13:48:

Not exactly the reply I was looking for. But, since you're here, can you list a few of the failure modes on your cards and the solutions? I do have a garage full of test equipment, less a logic analyzer.

Sorry, I actually had a very busy day and didn't even completely read the initial question. However georgel's comment stood out to me (being shorter). 😁
The most common issues that I saw with these SB 16 cards are related to faulty voltage regulators, faulty oscillators, or bad capacitors (more rare, but possible). I've never had one with a faulty chip (like a faulty DSP), but that doesn't mean it's not also a possibility.

2 x PGA132 / 5 x Socket 3 / 9 x Socket 7 / 12 x SS7 / 1 x Socket 8 / 14 x Slot 1 / 5 x Slot A
5 x Socket 370 / 8 x Socket A / 2 x Socket 478 / 2 x Socket 754 / 3 x Socket 939 / 4 x LGA775 / 1 x LGA1155
Current rig: Ryzen 5 3600X
Backup rig: Core i7 7700k

Reply 15 of 25, by trozx

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bloodem wrote on 2021-11-23, 18:05:
trozx wrote on 2021-11-23, 13:48:

Not exactly the reply I was looking for. But, since you're here, can you list a few of the failure modes on your cards and the solutions? I do have a garage full of test equipment, less a logic analyzer.

Sorry, I actually had a very busy day and didn't even completely read the initial question. However georgel's comment stood out to me (being shorter). 😁
The most common issues that I saw with these SB 16 cards are related to faulty voltage regulators, faulty oscillators, or bad capacitors (more rare, but possible). I've never had one with a faulty chip (like a faulty DSP), but that doesn't mean it's not also a possibility.

Thanks!

When you say faulty regulators, do you mean n0 voltage output, unstable voltage, or noisy output? -- all of the above? In my case I'm seeing a solid 9 and 5 V output on my DMM, but I have not scoped it yet.

Reply 16 of 25, by bloodem

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You're welcome!
If you do see the 9/5V output then they are most likely fine (although an oscilloscope would definitely help to eliminate all possible doubts).
The most common fault is no output voltage at all.
Make sure to also check capacitors (including all those little SMD caps). Those bastards can sometimes go short and depending on their location they can cause all sorts of weird issues.
For example, if you find a shorted decoupling capacitor, the card will most likely work just fine even if you simply remove it without even replacing it. 😀

2 x PGA132 / 5 x Socket 3 / 9 x Socket 7 / 12 x SS7 / 1 x Socket 8 / 14 x Slot 1 / 5 x Slot A
5 x Socket 370 / 8 x Socket A / 2 x Socket 478 / 2 x Socket 754 / 3 x Socket 939 / 4 x LGA775 / 1 x LGA1155
Current rig: Ryzen 5 3600X
Backup rig: Core i7 7700k

Reply 18 of 25, by trozx

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Cloudschatze wrote on 2021-11-24, 15:59:

Assuming the card-in-question lacks an ASP/CSP chip, are the IFSD and APSD jumpers appropriately closed?

Nice catch! Thanks!

I didn't consider that a possibility since the jumper pins for those settings are missing - but so is the ASP/CSP chip...

I quickly jumpered the vias with solder blobs and digital sound is restored. Sweet!

I'll probably add proper jumper pins at some point.

Reply 19 of 25, by georgel

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trozx wrote on 2021-11-25, 00:00:
Nice catch! Thanks! […]
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Cloudschatze wrote on 2021-11-24, 15:59:

Assuming the card-in-question lacks an ASP/CSP chip, are the IFSD and APSD jumpers appropriately closed?

Nice catch! Thanks!

I didn't consider that a possibility since the jumper pins for those settings are missing - but so is the ASP/CSP chip...

I quickly jumpered the vias with solder blobs and digital sound is restored. Sweet!

I'll probably add proper jumper pins at some point.

The jumper pins are called header. Are you sure that was missing and not only the junmpers themselves? So I was right and your claim "not my first rodeo" was a bit of a self-confident.