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MIF-IPC-B/MPU-401 woes

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Reply 20 of 24, by charlatan

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AppleSauce wrote on 2022-03-24, 13:44:
Oh wow that doesn't seem right at all can you send a picture of the card so we can see the ic chips? […]
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charlatan wrote on 2022-03-24, 12:17:
Boohyaka wrote on 2022-03-24, 12:07:

I don't see why it wouldn't. From what I can tell these cards are extremely basic anyway. When they run fine you completely forget they exist. No need for specific drivers. They just work from DOS, and in all Windows versions they are automatically detected and supported. I never tried it to be fair but I can't see how it could be a problem if the DB25 cable is off.

That's what I thought and it seems logical. Since I wrote that, I took a closer look at the card...

The wiki page states that IC3&6 should be 74LS08N and IC5 should be 74HCT04N. On my board, IC3 (Address Decode & Data Buffer) and IC5 (IRQ Select) are switched around.

Oh wow that doesn't seem right at all can you send a picture of the card so we can see the ic chips?

I guess whoever assembled the card had a bit of a la la land moment and missed the fact they installed the chips in reverse order.

Shame its not socketed it would be much easier to fix vs desoldering parts.

It certainly appears that way! It’s a bit hard to see but pic attached.

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Reply 21 of 24, by AppleSauce

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charlatan wrote on 2022-03-24, 13:56:
AppleSauce wrote on 2022-03-24, 13:44:
Oh wow that doesn't seem right at all can you send a picture of the card so we can see the ic chips? […]
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charlatan wrote on 2022-03-24, 12:17:

That's what I thought and it seems logical. Since I wrote that, I took a closer look at the card...

The wiki page states that IC3&6 should be 74LS08N and IC5 should be 74HCT04N. On my board, IC3 (Address Decode & Data Buffer) and IC5 (IRQ Select) are switched around.

Oh wow that doesn't seem right at all can you send a picture of the card so we can see the ic chips?

I guess whoever assembled the card had a bit of a la la land moment and missed the fact they installed the chips in reverse order.

Shame its not socketed it would be much easier to fix vs desoldering parts.

It certainly appears that way! It’s a bit hard to see but pic attached.

Well son of a gun that actually might be the problem.
My card has it the other way around.

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You mentioned getting a replacement card from them right?

I guess the silver lining is you'll have a backup one now at least if you chose to repair the botched older one at some point.

Reply 22 of 24, by charlatan

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AppleSauce wrote on 2022-03-24, 15:02:
Well son of a gun that actually might be the problem. My card has it the other way around. […]
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charlatan wrote on 2022-03-24, 13:56:
AppleSauce wrote on 2022-03-24, 13:44:

Oh wow that doesn't seem right at all can you send a picture of the card so we can see the ic chips?

I guess whoever assembled the card had a bit of a la la land moment and missed the fact they installed the chips in reverse order.

Shame its not socketed it would be much easier to fix vs desoldering parts.

It certainly appears that way! It’s a bit hard to see but pic attached.

Well son of a gun that actually might be the problem.
My card has it the other way around.

20220212_155653.jpg

You mentioned getting a replacement card from them right?

I guess the silver lining is you'll have a backup one now at least if you chose to repair the botched older one at some point.

Dropped off for a bit due to work...

It was a pain, but I de-soldered and switched those ICs. It solved the problem!

All my hardware is up and running now and setup was a non-issue once the card was fixed. What a relief...

Reply 23 of 24, by AppleSauce

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charlatan wrote on 2022-04-04, 12:04:
Dropped off for a bit due to work... […]
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AppleSauce wrote on 2022-03-24, 15:02:
Well son of a gun that actually might be the problem. My card has it the other way around. […]
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charlatan wrote on 2022-03-24, 13:56:

It certainly appears that way! It’s a bit hard to see but pic attached.

Well son of a gun that actually might be the problem.
My card has it the other way around.

20220212_155653.jpg

You mentioned getting a replacement card from them right?

I guess the silver lining is you'll have a backup one now at least if you chose to repair the botched older one at some point.

Dropped off for a bit due to work...

It was a pain, but I de-soldered and switched those ICs. It solved the problem!

All my hardware is up and running now and setup was a non-issue once the card was fixed. What a relief...

Awesome , glad to know you fixed it.
Enjoy your midi music 😁

Reply 24 of 24, by Boohyaka

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Wow good job figuring out the chips switch and fixing it! Great stuff 😁

All my hardware is up and running now and setup was a non-issue once the card was fixed. What a relief...

You bet! Your issues were so weird...