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NFG Forums => SIG X68000 => Topic started by: gypsie on September 17, 2017, 03:39:39 AM

Title: X68000 XVI shutdown PSU repair SOLVED!!!
Post by: gypsie on September 17, 2017, 03:39:39 AM
Hello everybody!!!

Once again, i ve got problem with my  X68000 XVI version.

The computer power up well, but the 16 mhz led is blinking and it shutdown 10 secondes after startup. I never opened it, capacitors are originals.

Do you think that is a PSU issue ?  I ve already my X68000 compact ( no adpcm sound) to repair.... I'm very unlucky .... :'(

Is it a known problem on the XVI ?

Thanks so much!
Title: Re: X68000 XVI shutdown
Post by: SuperDeadite on September 17, 2017, 11:05:32 AM
ALL X68000s MUST BE RECAPPED.
END OF STORY.
Title: Re: X68000 XVI shutdown
Post by: kamiboy on September 17, 2017, 06:54:50 PM
You are not unlucky, the failure rate of an X68000 that has not been recapped is 100%
Title: Re: X68000 XVI shutdown
Post by: gypsie on September 17, 2017, 07:17:33 PM
ok ok.

First i will try to finish my Compact with his adpcm issue.

Next, i will recap the XVI.

I spend more time repairing than playing..... >:(
Title: Re: X68000 XVI shutdown
Post by: gypsie on September 17, 2017, 07:22:40 PM
For info, is there a list of capacitors for the XVI ?
Title: Re: X68000 XVI shutdown
Post by: gypsie on September 25, 2017, 02:42:15 AM
NEWS 24/09/17

- Removed psu from my XVI and  tested it. Fan spin 5 seconds and the psu shutdown . So The culprit seems to be the psu.
- Opened the psu to check inside. Brown fluid on certain parts!!!!!
- 1 capacitor is curved on top.

(https://img11.hostingpics.net/thumbs/mini_68490320170925093735.jpg) (https://www.hostingpics.net/viewer.php?id=68490320170925093735.jpg)

(https://img11.hostingpics.net/thumbs/mini_99411020170925093847.jpg) (https://www.hostingpics.net/viewer.php?id=99411020170925093847.jpg)


Title: Re: X68000 XVI shutdown PSU repair
Post by: gypsie on September 25, 2017, 06:18:33 PM
Ho my god!!! Never saw such so bad capacitor!!!!! :o

(https://img11.hostingpics.net/thumbs/mini_39536920170925101054.jpg) (https://www.hostingpics.net/viewer.php?id=39536920170925101054.jpg)
Title: Re: X68000 XVI shutdown PSU repair
Post by: RobIvy64 on September 29, 2017, 01:44:11 AM
Time to change all the caps and clean up that leaked cap juice!
Title: Re: X68000 XVI shutdown PSU repair
Post by: gypsie on October 09, 2017, 06:50:23 PM
Hello,

I ve changed all capacitors but now Psu won't power up!!!!! >:( >:(

I ve checked all capacitors, fan, switches ( psu and computer) everything is ok.

I ve tried to shunt "gnd" + "power on" to start the psu without result.

Psu power up well after capacitor replacement... I don't understand the problem... :o
Title: Re: X68000 XVI shutdown PSU repair
Post by: JulBS0 on October 09, 2017, 09:44:29 PM
Hi,

The X68000 power supplies are powered up by applying a positive voltage to the Power Control line, unlike modern ATX PSUs.

To test it, connect the Power On line of the PSU to its +5Vsb/Vcc2 line through a resistor (approx. 4.7kOhms is OK). It should power up instantly.
I strongly advise against connecting directly the Power Control line to a +5V source, as it may fry the transistor used to control power.
Title: Re: X68000 XVI shutdown PSU repair
Post by: gypsie on October 09, 2017, 10:25:03 PM
Thank for advice.

I ve tested diode zener zd 31. With multimeter i can read 0.06mv in both direction. Diode not desoldered from pcb.
Title: Re: X68000 XVI shutdown PSU repair
Post by: gypsie on October 13, 2017, 04:59:13 AM
Quote from: JulBS0 on October 09, 2017, 09:44:29 PM
Hi,

The X68000 power supplies are powered up by applying a positive voltage to the Power Control line, unlike modern ATX PSUs.

To test it, connect the Power On line of the PSU to its +5Vsb/Vcc2 line through a resistor (approx. 4.7kOhms is OK). It should power up instantly.
I strongly advise against connecting directly the Power Control line to a +5V source, as it may fry the transistor used to control power.

Tested with 4,7kohms resistor but psu won't power up.

I will change ZD31.
Title: Re: X68000 XVI shutdown PSU repair SOLVED!!!
Post by: gypsie on October 15, 2017, 01:32:29 AM
Bingo!! ZD31 ( 6,8v 500mw) was dead .

(https://img15.hostingpics.net/thumbs/mini_281011201710141650051.jpg) (https://www.hostingpics.net/viewer.php?id=281011201710141650051.jpg)