- Joined
- Aug 30, 2001
- Posts
- 349
I offered to take a look at a friend's AES that could not boot up.
This was a very first revision board that did not have any daughterboards at all! Completely untouched save for the Unibios installation near the top, and which looked to be somewhat botched.
I got to removing the socket and starting replacing individual socket pins for each. The rationale was that the board has traces above and below and using such pins allows for clearer tracing and repair.
This image is post cleaning, it had looked like Vcc from pin 40 was going into the trace.
The individual sockets were snipped out of these guys.
All socketed, pre-trace check.
Trace-checked and re-wired.
A piece of thick cardboard to cushion the pcb traces from a flathead screwdriver, for future EPROM updates.
On testing, the AES kept randomly rebooting.
I recalled that a 10V power source was used on this 5V AES and I speculated that some power circuitry might be screwy. Poked around but nothing seemed amiss.
Prior to opening the AES, I had ordered a 5V, 2A PSU with the din plug's center polarity being +ve.
The polarity needed to be switched to center -ve and with no screws to the case, I did not want to crack open the adaptor to swap it there. So I got this in-line power switch a week later, and I swapped it within the switch case.
I did notice that the wire gauge(thickness) used by the in-line power switch was absolutely tiny.
I then thought to just re-wire the adaptor, which had a thicker gauge all through.
Lo and behold, it lives!
Take home:
1. Bios pin 31 was disconnected to the Sony CXK58256M-12L S-RAM. This appears to be the one causing the strange boot screen.
2. Severe flickering likely due to Vcc bleeding into a trace.
3. Insufficient gauge wire can cause resets!
4. Use a proper desoldering station. Or do the piggyback mount method, leaving the pcb well alone.
Putting it out there for future reference.
This was a very first revision board that did not have any daughterboards at all! Completely untouched save for the Unibios installation near the top, and which looked to be somewhat botched.
I got to removing the socket and starting replacing individual socket pins for each. The rationale was that the board has traces above and below and using such pins allows for clearer tracing and repair.
This image is post cleaning, it had looked like Vcc from pin 40 was going into the trace.
The individual sockets were snipped out of these guys.
All socketed, pre-trace check.
Trace-checked and re-wired.
A piece of thick cardboard to cushion the pcb traces from a flathead screwdriver, for future EPROM updates.
On testing, the AES kept randomly rebooting.
I recalled that a 10V power source was used on this 5V AES and I speculated that some power circuitry might be screwy. Poked around but nothing seemed amiss.
Prior to opening the AES, I had ordered a 5V, 2A PSU with the din plug's center polarity being +ve.
The polarity needed to be switched to center -ve and with no screws to the case, I did not want to crack open the adaptor to swap it there. So I got this in-line power switch a week later, and I swapped it within the switch case.
I did notice that the wire gauge(thickness) used by the in-line power switch was absolutely tiny.
I then thought to just re-wire the adaptor, which had a thicker gauge all through.
Lo and behold, it lives!
Take home:
1. Bios pin 31 was disconnected to the Sony CXK58256M-12L S-RAM. This appears to be the one causing the strange boot screen.
2. Severe flickering likely due to Vcc bleeding into a trace.
3. Insufficient gauge wire can cause resets!
4. Use a proper desoldering station. Or do the piggyback mount method, leaving the pcb well alone.
Putting it out there for future reference.
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