English Amiga Board - View Single Post - Amiga CD32 will not boot. Green screen power light blinks, later a black screen

retrofriends · 20 July 2020, 01:12

Hello there. Looking for some help with a CD32. What I have discovered and what I have done:
It came to me with a green screen that would show itself for 10 blinks of the power LED, then the unit resets and repeats the green screen / power blink.
It supposedly came from a person who replaced the processor. After thorough examination, I found the processor was not the part changed, it was AKIKO. I decided to test chip ram with my oscilloscope, and found that the first RAM chip (U16) had no CAS signal, yet the others were fine (U17-U19). So I traced it to a broken trace under the AKIKO chip. I installed a bodge wire to repair this. (Hopefully this portion of the repair will be helpful if someone else gets a green screen / light blink on their CD32).

Now the unit boots to a black screen. I am assuming that it is booting past the chipmem check. The power LED is dim for a second then goes bright, which I assume to be correct operation. I have examined the large capacitors. They are the correct orientation, and seem to be taller than the factory ones, so I am assuming someone did a recap already (likely done before trying the AKIKO replacement).

Any suggestions would be appreciated. I have tested continuity on AKIKO's pins to the pads and all is good. I will try continuity from AKIKO to other points/chips in case there are more broken traces to AKIKO.

I have a DiagROM for CD32 on the way. Anyone had experience with this application? I usually use the serial output, but the CD32 doesn't have a port. I know it has serial in the keyboard/aux port, and another in the expansion connector, but they are TTL. Has anyone tried a TTL-to-USB converter to connect it to a PC? Which port does the DiagROM output to, the keyboard/aux or the rear expansion?

20 July 2020, 01:12	#1
retrofriends Registered User Join Date: Dec 2019 Location: California / USA Posts: 25	Amiga CD32 will not boot. Green screen power light blinks, later a black screen Hello there. Looking for some help with a CD32. What I have discovered and what I have done: It came to me with a green screen that would show itself for 10 blinks of the power LED, then the unit resets and repeats the green screen / power blink. It supposedly came from a person who replaced the processor. After thorough examination, I found the processor was not the part changed, it was AKIKO. I decided to test chip ram with my oscilloscope, and found that the first RAM chip (U16) had no CAS signal, yet the others were fine (U17-U19). So I traced it to a broken trace under the AKIKO chip. I installed a bodge wire to repair this. (Hopefully this portion of the repair will be helpful if someone else gets a green screen / light blink on their CD32). Now the unit boots to a black screen. I am assuming that it is booting past the chipmem check. The power LED is dim for a second then goes bright, which I assume to be correct operation. I have examined the large capacitors. They are the correct orientation, and seem to be taller than the factory ones, so I am assuming someone did a recap already (likely done before trying the AKIKO replacement). Any suggestions would be appreciated. I have tested continuity on AKIKO's pins to the pads and all is good. I will try continuity from AKIKO to other points/chips in case there are more broken traces to AKIKO. I have a DiagROM for CD32 on the way. Anyone had experience with this application? I usually use the serial output, but the CD32 doesn't have a port. I know it has serial in the keyboard/aux port, and another in the expansion connector, but they are TTL. Has anyone tried a TTL-to-USB converter to connect it to a PC? Which port does the DiagROM output to, the keyboard/aux or the rear expansion?