Dragon 32 clicking the relay like crazy

[3L_S4N70]

Hi everyone,

first of al, thanks to admit me to join this awesome community.

Two months ago I purchased a Dragon 32, and I was able to test two days ago. The unit lacks the PSU, so I bypassed the power board and directly fed 12, 5, -5 and GND to the first four pins of the connection between power and principal PCBs.Weirdly, I got to see the device to succesfully boot like 10% of the times; another 10% I saw the screen correctly, but fully lacking green colour, all was grey and black; another let's say 30% of the times I got a corrupted image similar to that when the ROM is not OK; and have the time, no image... and all the times, in a few seconds, ended up in no image, and a fast clicking presumely coming from the relay.

Do any of you happen to know what the problem could be, or maybe where to start troubleshooting, and even which equipment is the more suitable for the task? I have read all the hardware subforum, and searched along the full forum, but have found nothing similar (I may have missed it though); I have not found anything similar in the internet, nor in a Telegram group either, so any help is much appreciated.

Best,
Guillermo

[sixxie]

What are you using to supply power? PC PSU? Is it possible it's not certain the load is enough and is cutting out? How about that pin you're supposed to keep connected to something on a PC?

[3L_S4N70]

Further info: I am feeding the system with 9 volts at 2.22A, converted to 12 volts and -5 volts, and from 12 volts to 5 volts. I am doing it this way because when I was converting directly from 9 to 5, the power loss was noticeable (the 5 volts path was falling up to 3 volts).

I have to test with a PC power supply, but in the meatime, I appreciate any comment if you feel there are any more things I should try also/instead.

Thanks in advance

-----

Thanks sixxie for your comment, I was still wrting the info above, and answering your question regarding power cut, nope, the volts at the paths seem to still be there after computer failure, so I assume the power is not getting cut...

[dublevay]

Further info: I am feeding the system with 9 volts at 2.22A, converted to 12 volts and -5 volts, and from 12 volts to 5 volts. I am doing it this way because when I was converting directly from 9 to 5, the power loss was noticeable (the 5 volts path was falling up to 3 volts).

I have to test with a PC power supply, but in the meatime, I appreciate any comment if you feel there are any more things I should try also/instead.

Thanks in advance

-----

Thanks sixxie for your comment, I was still wrting the info above, and answering your question regarding power cut, nope, the volts at the paths seem to still be there after computer failure, so I assume the power is not getting cut...

Hi

Regarding the power supply... this may be the most suitable replacement for you.

https://www.dragonplus-electronics.co.u ... -jan-2022/.

Will be available over the next day or so.

Thanks

John

[3L_S4N70]

Hi all, I am just swriting to let you know I solved the issue. I happened to not knpw the most important voltage on the D32 was 5 volts. I solved the issue just using a 5 volt PSU (indeed, a USB PD capable one, providing up to 5 V/2.24 A) and getting both 12 V and -5 V out of it. Everything is working like a charm now.

Thanks all for your prompts.