x68000:soft_power_switch_troubleshooting_and_repair
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x68000:soft_power_switch_troubleshooting_and_repair [2012/11/20 23:55] – eidis | x68000:soft_power_switch_troubleshooting_and_repair [2019/08/27 20:45] (current) – external edit 127.0.0.1 | ||
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- | ===== Soft power switch | + | ===== Soft-power troubleshooting and repair ===== |
- | The following information is kind contribution by our forum members **Lydux** and **Caius** and this fix was applied to X68000 | + | The following information is kind contribution by our forum members **Lydux** and **Caius** and this fix was applied to X68000 SUPER and Expert HD. |
- | The symptoms: X68000 powers on fine, but does not shut down when the soft-power button is pressed. The screen fades, Power LED does not change from Green to Red and the system | + | **The symptoms:** X68000 powers on fine, but does not shut down when the soft-power button is pressed. The screen fades, Power LED does not change from Green to Red and the PSU fan keeps spinning. The same happens with a regular ATX PSU. |
If this is your case then the problem is almost surely located on the IO board. | If this is your case then the problem is almost surely located on the IO board. | ||
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{{: | {{: | ||
- | A condition using 4 signals is used to get the X68K turn on/off correctly : | + | **A condition using 4 signals is used to get the X68K turn on/off correctly :** |
- | | + | |
*Via the RTC (Real Time Clock) alarm signal (/ | *Via the RTC (Real Time Clock) alarm signal (/ | ||
- | *From the expansion bus (signal | + | *From the expansion bus (/EXPWON) |
- | *A signal from the system controller | + | *Via the front power switch |
+ | *Via the soft-sequence signal | ||
- | In normal operation, all these 4 signals must go logic High (+5v) to get a system shutdown. | + | In normal operation, all these 4 signals must go to logic High (+5v) to get a system shutdown. |
The problem might be due to a signal that is always stuck Low. | The problem might be due to a signal that is always stuck Low. | ||
- | If you look to the buffered | + | If you look at the Buffered |
+ | |||
+ | **They can be queried via software and are connected like this :** | ||
|/ | |/ | ||
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**A program for testing these signals can be found here :** | **A program for testing these signals can be found here :** | ||
- | [[http:// | + | [[http:// |
**Execute it more than one time. You should get :** | **Execute it more than one time. You should get :** | ||
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*PSON = 0 | *PSON = 0 | ||
- | **If RTC_ALARM always | + | **If RTC_ALARM always |
*Bad RTC chip (RP5C15) | *Bad RTC chip (RP5C15) | ||
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*Bad IC28 (74LS08) (stuck output). | *Bad IC28 (74LS08) (stuck output). | ||
*Bad Q9 transistor (shorted). | *Bad Q9 transistor (shorted). | ||
- | *Bad C64 (generating noise). | + | *Bad C64 capacitor |
*IC29 (74LS244) might have bad output on pin 5. | *IC29 (74LS244) might have bad output on pin 5. | ||
*The power signal from the main board, which I miss infos actually. A fix to this could be soldering a 10K ohm resistor between IC28 pin 10 and 14. | *The power signal from the main board, which I miss infos actually. A fix to this could be soldering a 10K ohm resistor between IC28 pin 10 and 14. | ||
x68000/soft_power_switch_troubleshooting_and_repair.txt · Last modified: 2019/08/27 20:45 by 127.0.0.1