R90=472
R91=472
R94=472
C111=2u2
C151=2u2

Postman5 wrote on 2025-05-07, 15:41:

R90=472 R91=472 R94=472 C111=2u2 C151=2u2 […]
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R90=472
R91=472
R94=472
C111=2u2
C151=2u2

Hi Postman5,

Thanks for sharing those values. I was looking for one of those 2u2 caps as my Helios AT-2475 suffered the same fate..
Do you also happen to know the value of C157. It's a smaller one to the right of the right most RAM chip..
Much appreciated!

pipmastah wrote on 2025-06-01, 22:26:

Hi Postman5, […]
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Postman5 wrote on 2025-05-07, 15:41:

R90=472 R91=472 R94=472 C111=2u2 C151=2u2 […]
Show full quote

R90=472
R91=472
R94=472
C111=2u2
C151=2u2

Hi Postman5,

Thanks for sharing those values. I was looking for one of those 2u2 caps as my Helios AT-2475 suffered the same fate..
Do you also happen to know the value of C157. It's a smaller one to the right of the right most RAM chip..
Much appreciated!

Unfortunately, I don't have this board at hand and I won't be able to remove it and measure it. However, C157 is a blocking capacitor in the power supply circuit. You can safely install any capacitor of the same size with a capacity of 10n...200n in this place. Or don't install anything - the board will still work.

Postman5 wrote on 2025-06-02, 07:41:

pipmastah wrote on 2025-06-01, 22:26:

Hi Postman5, […]
Show full quote

Postman5 wrote on 2025-05-07, 15:41:

R90=472 R91=472 R94=472 C111=2u2 C151=2u2 […]
Show full quote

R90=472
R91=472
R94=472
C111=2u2
C151=2u2

Hi Postman5,

Thanks for sharing those values. I was looking for one of those 2u2 caps as my Helios AT-2475 suffered the same fate..
Do you also happen to know the value of C157. It's a smaller one to the right of the right most RAM chip..
Much appreciated!

Unfortunately, I don't have this board at hand and I won't be able to remove it and measure it. However, C157 is a blocking capacitor in the power supply circuit. You can safely install any capacitor of the same size with a capacity of 10n...200n in this place. Or don't install anything - the board will still work.

Thanks for your reply. I guess I'll solder on a random decoupling cap from one of my donor Matrox cards at the C157 position.
One of the 2u2 caps, C151 has also been knocked off. Do you reckon I can replace that with a 4u7 unit? Those 2u2's are very hard to find. Could order a few of course but lazy as I am: If a 4u7 would suffice and the card'd be happy i'd be too 😉

pipmastah wrote on 2025-06-02, 09:12:

Postman5 wrote on 2025-06-02, 07:41:

pipmastah wrote on 2025-06-01, 22:26:

Hi Postman5, […]
Show full quote

Hi Postman5,

Thanks for sharing those values. I was looking for one of those 2u2 caps as my Helios AT-2475 suffered the same fate..
Do you also happen to know the value of C157. It's a smaller one to the right of the right most RAM chip..
Much appreciated!

Unfortunately, I don't have this board at hand and I won't be able to remove it and measure it. However, C157 is a blocking capacitor in the power supply circuit. You can safely install any capacitor of the same size with a capacity of 10n...200n in this place. Or don't install anything - the board will still work.

Thanks for your reply. I guess I'll solder on a random decoupling cap from one of my donor Matrox cards at the C157 position.
One of the 2u2 caps, C151 has also been knocked off. Do you reckon I can replace that with a 4u7 unit? Those 2u2's are very hard to find. Could order a few of course but lazy as I am: If a 4u7 would suffice and the card'd be happy i'd be too 😉

Of course, it is not necessary to have exactly 2u2. 2u2...10u will work well.