Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-03-04, 19:56
Deunan wrote: I'm sorry but I can't view that video, says it's not available. Wrong link maybe? Sorry, always forget to set it public, now you can view it.
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-03-04, 18:47
OK, i did the capacitor replacement, with no changes, even the new capacitor keeps some current on power off. But while i was tesiting the TC4069 voltages discovered this: https://youtu.be/UgNND2ogCgI Does it make any sense to you?
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-03-04, 17:13
Well i've measured the 4069: https://i.imgur.com/tcay3Yz.png Anyways, i've desoldered, 3 suspicious capacitors, especially the red one below R13 (C83), wich was snap open and burnt! that wasnt visible without extacting it: https://i.imgur.com/fRgQLKy.jpg Also desoldered, the suspicious 4,1 volts …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-03-03, 12:13
Hi, today completed the circuit using a cable bypass, sadly nothing changed, still no signal from the inverter to rtc, this scheme shows how it is now conected: May be i need to change the suspicious capacitors now, its only a couple of them.
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-03-01, 19:59
Ok i've tested the circuit as the image, and its not working. Basically R13 Right end is not conected with any of the 4069 pins. Tomorrow / sunday will do some bypasses and try to boot all in video to see if there is any changes.
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-27, 14:43
Will test the circuit this weekend, i'm out of time!
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-25, 19:05
Ok, ill forget about the osciloscope then for now. I did resolder all pins in 4069 and RTC, also R13 then Did the tests: - There was no signal, 0v from 4069 pin 12, to RTC pin 2. - This is the conetection between RTC and KB_ROM https://i.imgur.com/ePx69Bg.jpg - And finally R13 left end IS conected …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-25, 12:21
Posting from work break... I think your problems are caused by the battery leak (corroded traces or vias). Photos you posted yesterday show there's quite some damage. All the traces that have as much as a single point of corrosion must be checked for continuity. Removing the parts from the affected …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-24, 21:11
No, thanks to you (and all others) for helping me, im learning a lot! I did the bleeding test before, but got the same behaviour, thats why i didnt say anything about it. - About the battery, all test was done without battery in the slot. Now i did one test more WITH battery on, a CR2032 3V, got …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-24, 18:29
Ok more info: - Resoldered all suspicious capacitors, now i have a clean signal on both "unreadeables", and C74 & C86 are now dry on power off, so 4 fixed. - 2 capacitors C82 an C83 still holds charge while power is off, also while i was cheking voltages on C83 system continued the boot sequence and …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-24, 14:30
Ok, im gonna answer in order. - About the external battery im gonna skip this until is mandatory. - About the clearing of the CMOS, well i've downloaded several manuals from variants of this board (not this one exactly) and i've not seen any clear_cmos jumper reference, may be is designed as is. - …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-24, 12:18
Thanks for the input Deunan, ill take some time to decypher your message hahaha Ill post some update soon.
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-24, 10:19
Ok here we go... tried to track where the diodes are conected so i did a little schema: - For the first: it is conected to the 4 pin header, but cant find any conection to other components in that pin. I have to say, that this pc was never opened and it came unpopulated, also, another user posted …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-23, 13:06
Some update... Not finished with the capacitor testing and the jumper stuff due to lack of time, i will do all this sunday (tomorrow). Meanhile, got a lucky deal and now i have another pc, its a philips nms 9115, an intel 8088, 768 ram, HDD20b, floppy 5.25" and 3.5"(capacity unknown for both), …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-21, 19:05
Today got no time for much testing. But enought to check some capacitors (not all). Indeed a couple of them presented some charge after power off, and then losing it slowly, like 5V on power, an then 1,xV and dropping, tomorrow will do a complete checking of all capacitors. About the diodes, my …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-20, 19:24
Thanks Deunan! Well the problem is not random at all. As Predator99 told me, the issue only appears when capacitors has energy. What i mean, i can reproduce the state of the beep codes everytime i want (i need 1-2 days to dry the caps). So, as Predator 99 stated i think i have to replace the caps …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-20, 16:56
New update, i finally got the beep code after waiting couple of days for capacitors to dry, is definetly a 1-1-3 code: https://i.imgur.com/0k2Is9U.jpg You can see it on video here -> https://youtu.be/Yo9bmBHsZ8Y So seems is something CMOS related, from other website: 1-1-3 CMOS read/write error …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-17, 19:09
I really respect your persistence, good work so far! I think your problem are the capacitors. But where to start to exchange - I have no idea. The 01 and 02 doesnt mean to much - the board crashes shortly after start. But you can be sure BIOS+CPU are working. Beep-Codes will be interesting. If you …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-17, 15:09
Got some time to work on in so Ill post an update: - Already replaced the keyboard rom socket, it had corrosion, and some broken pin slots, also it had 3 pads broken, so i had to bridge (patch?) them. Now its working. - Installed a new batery https://i.imgur.com/Uk7b9Zo.jpg - Done first test in 48h …
Re: Old KEnitec 286 Plus (suntac) Rescue, will need help.
Posted on 2019-02-14, 14:58
New video: https://www.youtube.com/watch?v=l9Ab0Y0JXPw&feature=youtu.be Well i tried again with the graphic card and the postcard in th slots 1 & 2 respectively. I got no beep codes, but now i am not getting any error code, the post card reads "-- --" :S. Also irdy led is permanently off, all others …
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