Amiga CD32 CXA2075 or CXA1645 mod

[digital123]

Hello everyone.

Got CD32 on bench with bad composite out (out of sync, no colour) Band filters and delay line gone.

Want to upgrade to either CXA2075 or CXA1645 encoder, all what I've found is A600/A1200 mod described but no CD32.

Comparing pinouts CXA1145 to CXA2075 - audio ones are obvious (8 and 9 lifted) , pins 15, 16 , 17, 18 are not connected in A600/A1200 as there is no S-Video (pin 15 and 16) and pin 17 and 18 are different to CXA1145. CXA2075 pin 17 is connected to pin 12 with 2.61K resistor, but with CD32 there is S-Video present

My question is: does pins 15 and 16 are still soldered to the board to get S-Video out? or there is any other mods to do. Also what else need to be removed apart from band filters/ dealy line.

Maybe someone did this mod?

Thanks!

[terriblefire]

Hello everyone.

Got CD32 on bench with bad composite out (out of sync, no colour) Band filters and delay line gone.

Want to upgrade to either CXA2075 or CXA1645 encoder, all what I've found is A600/A1200 mod described but no CD32.

Comparing pinouts CXA1145 to CXA2075 - audio ones are obvious (8 and 9 lifted) , pins 15, 16 , 17, 18 are not connected in A600/A1200 as there is no S-Video (pin 15 and 16) and pin 17 and 18 are different to CXA1145. CXA2075 pin 17 is connected to pin 12 with 2.61K resistor, but with CD32 there is S-Video present

My question is: does pins 15 and 16 are still soldered to the board to get S-Video out? or there is any other mods to do. Also what else need to be removed apart from band filters/ dealy line.

Maybe someone did this mod?

Thanks!

I think either @go0se or @supaduper did a mod like this for me. They've both done me so many favours i forget which.

[supaduper]

Use the CXA2075 thats the best one, also you do not have to remove anything off the board as it will not use them anyway the two pins you lift off are the audio then just solder a link to the to pads under them

I have a few CXA2075 so email me your address again and I will post one with a resistor

details on how to do the mod below, just the same for the CD32

https://www.ikod.se/cxa2075m/

[digital123]

I think either @go0se or @supaduper did a mod like this for me. They've both done me so many favours i forget which.

Thanks Stephen, and it was a pleasure to meet you finally at Kickstart venue (I'm the bloke behind GoDRIvE's )

[digital123]

Use the CXA2075 thats the best one, also you do not have to remove anything off the board as it will not use them anyway the two pins you lift off are the audio then just solder a link to the to pads under them

I have a few CXA2075 so email me your address again and I will post one with a resistor

details on how to do the mod below, just the same for the CD32

https://www.ikod.se/cxa2075m/

Thanks Mark, It's very kind of you as usual...I'll PM you my address.

Looks like only audio pads are lifted, what about all passives underneath?? I've located them in CD32, do I need to removbe these?

Best regards Dominik

[supaduper]

Use the CXA2075 thats the best one, also you do not have to remove anything off the board as it will not use them anyway the two pins you lift off are the audio then just solder a link to the to pads under them

I have a few CXA2075 so email me your address again and I will post one with a resistor

details on how to do the mod below, just the same for the CD32

https://www.ikod.se/cxa2075m/

Thanks Mark, It's very kind of you as usual...I'll PM you my address.

Looks like only audio pads are lifted, what about all passives underneath?? I've located them in CD32, do I need to removbe these?

Best regards Dominik

Hi Dom, I did not remove them but you can if you want

[digital123]

Thanks Mark.

Once done, will report back.

Best regards Dominik

[digital123]

Bit of an update:

Received couple of CXA2075M from Supaduper today (Thanks Mark!)

Found bit of the time to install it in CD32 and, If installed like link suggested ( with resistor R2.61k between 17 and VCC, measured 2.59k), I did get colour now on composite but screen still was out of sinc.
I've isolated pin 17 and 18(put a bit of the kapton tape) and also removed all passives around to make sure it won't interfere with composite or S-Video.
Once that done, finally got stable composite.

Like Supaduper said, it worked for him without isolating anything or removing any passives, but this is my experience...don't know how much it differs but tried both IC's and same results.

Also what I've noticed, CXA2075M running pretty warm . Left if running idle on boot screen for about 30min, and it get up to about 53"C

I've read peaple getting mixture results, some of them running cold where some oothers reporting it gets hot, another one which con't really know why.

Anyone having similar experience?

Best regards Dominik

[supaduper]

Glad you got it sorted Dom, regarding the removing the components I am just lazy lol and found it worked ok for me so left them, but probably best to remove them like you did, I never checked if mine got hot as it is on a spare CD32 mobo, I will try it see if it does, also you could put a small heat sink on the chip to cool it ,well on some of it anyway because the resistor is in the way

ALL the best

[digital123]

Thanks.

It was about 53"C for some time. Found some heatsink and modified it to fit . temp drops to 45"C which is reasonable....been running it for 2h no problem.
Wondering what sort of temp you getting on yours

Dominik