Re: IBM PS/1 repair

Posted on 2022-05-24, 09:24

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, start by checking the connector itself, if not heavy corrosion. then maybe check solder joint on the video chip itself and video ram. thoses machines are a bit complicated when problem come from motherboard, as mostly all part of the chipset use custom gate arrays.

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Re: IBM PS/1 2011 - Original keyboard problem [Help]

Posted on 2022-05-24, 08:54

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Retromania wrote on 2022-05-23, 22:18: Does anybody know why sometimes it works and sometimes not? i gived you the answer, maybe not very clealry, i admit. your problem is capacitors inside the keyboard, on the controller board.

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Re: IBM PS/1 2011 - Original keyboard problem [Help]

Posted on 2022-05-22, 16:32

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

capacitors, capacitors... and capacitors :D good luck if you've never opened thoses keyboards, i strongly suggest you to follow a tutorial. back some years ago, when some informations were less available, i opened one out of curiosity... and never reassemble it. i don't remember exactly how i did, …

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Re: I'm silly and I bought something new. But it has a problem...

Posted on 2022-05-21, 06:39

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

short answer : yes, you can safely swap them 😀

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Re: Short on ISA slots? Try this.

Posted on 2022-05-04, 22:48

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hamby wrote on 2022-05-04, 21:38: to create a "null" bridgeboard for my Amiga that would give me access to the ISA slots just to be sure i understand what you mean, you already have a pc bridgeboard ? or you want to use isa cards on the amiga itself ?

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Re: Upgrading a 386SX - some advice!

Posted on 2022-05-02, 20:00

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by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

ohhh i realize i didn't put my contribution here. i successfully upgraded 2 PS/2's with SXLC2 50 and 40 Mhz chip. first is a model 35 (isa) originally with a SX20, successfully upgraded with the SXLC2 50 G50 (without 3,3v mod) , overclocked to 33 MHz. and for bonus, cache is enabled by bios. and …

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Re: How can I safely transplant a 160-pin QFP chip?

Posted on 2022-05-02, 12:17

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

not more than others said :) BUT... a safely thing you can do, is put the donor card in oven for 1 or 2 hours at 50/60°C before desoldering. why ? because of moisture. strongly heating old chip that have been in storage for long can have absorb moisture. and when you strongly heat them, mositure …

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Re: Anyone know the polarity on the 3 leg tantalums in an IBM PS/2 type 8525 (Model 25). Color monitor/8086

Posted on 2022-02-13, 01:09

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

yes, a bit off topic, but still useful i guess 😀 they're also not custom made for ibm. you can still buy 3 legged tantalum from digikey for exemple. they're only not widely used, it's different. but to confirm what i said : https://i.stack.imgur.com/oqEyK.png

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Re: Anyone know the polarity on the 3 leg tantalums in an IBM PS/2 type 8525 (Model 25). Color monitor/8086

Posted on 2022-02-12, 20:56

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

no, they're not "pass" or anything else special. 3 leads just give the ability to not care about the way you mount them. in any way, you can't be wrong. that's all. i replaced thoses in a model 30 8086 by regular aluminium without any issues. You seem to think there were some new guys on the …

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Re: Anyone know the polarity on the 3 leg tantalums in an IBM PS/2 type 8525 (Model 25). Color monitor/8086

Posted on 2022-02-11, 22:25

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I disagree with the "Replacing 3-legged with 2-legged" on that page. You have 3 leads because it's a pass capacitor after all. no, they're not "pass" or anything else special. 3 leads just give the ability to not care about the way you mount them. in any way, you can't be wrong. that's all. i …

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Re: Dead Voodoo 1 with visibly degraded components.

Posted on 2022-01-23, 14:44

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

you can also check continuity of corroded vias, some of them are probably cut. very strange corrosive attack...

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Re: IBM PS/2 80 Series motherboard

Posted on 2021-11-29, 00:12

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Different PS/2 models used different floppy drives interfaces even the bezel to match is different too! eg: 55SX, 70, 80, 85, 95, 77 used different floppy interfaces pinout. just to precise, there's only 2 type of drives. (or maybe 3, with the strange "asterisque" story, but nothing to concern here …

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Re: IBM PS/2 80 Series motherboard

Posted on 2021-11-28, 23:05

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

oh no... you're in MCA madness, welcome :) your best luck actually is to go with scsi. then a sd2scsi, or an acard adaptor. actually, there's no CF/IDE solution. ide controller exist (there's one model for sure) but it's not a standard ide, dos and windows can't use it natively. and is not bootable. …

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Re: IBM PS/2 80 Series motherboard

Posted on 2021-11-28, 20:43

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Short answer, NO. Long answer, yes. - There exists upgrade boards for most PS/2 machines. They exist in the same way that a virgin exists at a whorehouse. If you're lucky enough to find one, its going to cost you an arm and leg. And I'm not being funny. The last 286 > 486 upgrade board I saw for …

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Re: New processors for old sockets.

Posted on 2021-11-13, 17:36

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by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just imagine your old IBM 5150 running doom with the original board (and a futuristic computer shoved in the CPU socket) there's a big difference between pc and amiga, the amiga had the ability to have his local bus extended. this can easily make use of the accelerator local fast ram, local drive …

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Re: 486 Motherboard blown capacitor

Posted on 2021-11-02, 12:52

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

it might just be the manufacturer "signature". but nothing you have to worry about. just replace it with what you found, and you'll be fine. 😀

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Re: 486 Motherboard blown capacitor

Posted on 2021-10-31, 13:47

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

remove it, and measure voltage to see what margin you'll need. but as 12V is the max voltage on motherboard, you can always put 16/25V anywhere on the mothertboard and be totally safe. you can replace it with regular aluminium capacitor, or pick antoher tantalum. for the value, it's not very …

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Re: Amiga 500 workbench help kickstart roms

Posted on 2021-10-29, 10:16

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I mean, a little RAM upgrade and a simple CPU swap (68000 out, 68010 in) is one thing. Installing an huge, expensive behemoth of a CPU card something completely different. It's like installing a parasite on a host. it's a really weird point of view. in fact, you don't like the native ability of the …

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Re: Suggestions for build on a PS/2 77s?

Posted on 2021-10-17, 17:50

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The ram ***SHOULD*** be standard 72 pin simms. they are. BUT... as any desktop PS/2, it'll require parity. not ecc as you said, but parity. then, memory need the presence bit to be set according to their capacity/speed, that's a point where you can easily be trapped, as a lot of fpm/edo sticks …

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Re: Recapping Capacitor List

Posted on 2021-10-13, 15:28

by

by whaka

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So basically anything near the output where the atx connector is should be low esr then? if you want to know where you go : check the original capacitor brand serie datasheet, and see what they say... on psu output, if they did their design with "normal" ones, you can go in regulation troubles with …

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