Re: Socket 7 Motherboard issue - can't seek CD drive, floppy works only for few seconds

Posted on 2019-11-12, 22:44

by

by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have experienced similar behaviors when RAM caching, burst and wait state settings in BIOS weren't appealing to the whole configuration. Resetting to defaults and tweaking the settings step by step helped. Otherwise you really might have some fault on the board.

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Re: PSU - 60W - 386/486 OK - Pentium does it work?

Posted on 2019-08-05, 20:58

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've had a 486 system with a native 82 Watt psu. Aside from the standard AT motherboard connectors it could support 2 FDD and 2 HDD (Two small and two big peripheral molex connectors). It could run Pentium boards no problem too since those aren't too power hungry. It really depends on how many disk …

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Re: 16 bit ISA post card

Posted on 2019-08-02, 07:40

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The 7 seg displays are driven by a pair of 7447 BCD to 7 segment decoders. Values between 0 and 9 will display correctly. Values between A and F will display "hieroglyphics" not hex digits. (The 7447 dataset will allow you to decode these into "proper" hex.) Thanks! Almost started swapping out …

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16 bit ISA post card

Posted on 2019-08-01, 17:46

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hello I found this old post card on the flea market. Made in 1993, standard ISA 16 bit bus. It has a pair of seven segment display, lots of leds, some dip switches and one tactile switch. I could find any info about it. Has a lot of 74 series logic and some bcd to hex converter ICs. It was a bit …

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Re: Old hard disk data recovery - swapped controller board, still nothing (SATA WD GREEN drive)

Posted on 2019-06-13, 12:39

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There is usually an EEPROM which contains calibration data. You will maybe need to swap the eeprom over onto the new PCB? U1 SMOOTH chip is the spindle motor pwm/head preamp-servo controller stage. The external ROM location, U12 is not populated meaning the drive loads the rom adaptives from the …

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Re: Blown resistor in XT PSU?

Posted on 2019-03-26, 11:04

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What do you think might have happened and how would I go about repairing it? Sorry if this sounds dumb - I know very little about electronics and soldering but I want to learn more about it :) In the circuit the blown resistor at R50 position creates a so called "snubber" with capacitor on C24 for …

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Re: A tale of two PSUs

Posted on 2019-03-26, 09:36

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ideally it can be modded in a way that permits the sensor to be attached to the secondary's hottest parts respective the parts that do most damage when failing. I guess this could be the cooler of the secondary rectifier? This psu is 70% efficient at best. Still running after 20+ years and there …

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Re: A tale of two PSUs

Posted on 2019-03-25, 09:55

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi Retardware! This Enermax unit is a group regulated desing, so unless the 5V rail is loaded with at least 2-3 Amps the other voltages will be acting funny. If you plan to adjust the fan speed you can connect a 4.7kohm resistor in parallel with that ttc103 thermistor. This will boost up that …

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Re: Zeck AT Power supply

Posted on 2019-02-28, 14:58

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Would be nice if this is a standard AT PSU, because from the looks of things, the components are top notch. Even a nice Panasonic fan. I would imagine this wasn't the cheapest PSU when it was made. Yeah this Lite-on unit is fairly overbuilt and the components are high quality. That UC3844 drives a …

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Re: Zeck AT Power supply

Posted on 2019-02-28, 10:47

by

by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Would be nice if this is a standard AT PSU, because from the looks of things, the components are top notch. Even a nice Panasonic fan. I would imagine this wasn't the cheapest PSU when it was made. Yeah this Lite-on unit is fairly overbuilt and the components are high quality. That UC3844 drives a …

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Re: Blown Fuse In New AT Power Supply

Posted on 2019-02-23, 19:09

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I tried a couple of stores that I could drive to but they dont have any in this range on the old caps is "85 degrees 330 uf 250 volts" are these caps electrolytic capacitors or some other type as now I would like to give it a go fixing it from what everyone said about it being a good/decent PS. …

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Re: Zeck AT Power supply

Posted on 2019-02-22, 22:25

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Right. Took some pictures of the guts of the thing. I'm unable to identify anything other than the who large Panasonics. Those 470uF primary caps are well enough for 200W total power. There is minimal EMI input filtering. There is a bridge rectifier, probably 4- 6 Amp one. Primary switching seems …

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Re: Blown Fuse In New AT Power Supply

Posted on 2019-02-21, 21:47

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Actually it looks exactly like a HS 200 (High Perfection Technologies) Unit. DSCF0241.jpg DSCF0242.jpg One of their redundant 300W AT units: DSCF0465.jpg DSCF0470.jpg I'm not sure who are the OEM behind these though... If you have the parts and know-how just replace the primary caps and fuse and see …

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Re: Blown Fuse In New AT Power Supply

Posted on 2019-02-19, 15:00

by

by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Your first step should be checking the caps, MOV, and diode pack for any dead shorts. Yeah. Definately a short in the primary. That fuse wire just evaporated inside the glass. In an overcurrent event it would just break open. Visually the Q1 Q2 BJTs seem fine. Probalby the primary C2 C3 caps are …

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Re: Which of these AT PSUs suck least?

Posted on 2018-11-26, 10:04

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The Power Tronic has 1990 date labeled on it. ES-250T Solar Power has 2002, the other SP 1998. ATNG built Pemier can't be too old. As others have suggested you should open them up and insepct for signs of ageing. I've had "new" off-the-shelf FSP bulid AT units with bulging capacitors and regulation …

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Re: A tale of two PSUs

Posted on 2018-05-18, 11:41

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

My question, is this AT PSU worth salvaging by replacing the caps or not? It's '90 generic at best. Has some EMI input filtering, though not all components are the safety approved type. Has a bridge rectifier, small input capacitors and the primary transistors are plastic to-220 types. Main …

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Re: FIC-486-VIP-IO VRM components

Posted on 2015-12-11, 11:15

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thanks for the hint! It's going to be sorted out after all. Brostenen will take some pictures of his board.

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Re: FIC-486-VIP-IO VRM components

Posted on 2015-12-10, 21:08

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I sort of managed to figure out the values, but it would hurt to make sure 😊 I'm still selecting the right coil also.

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FIC-486-VIP-IO VRM components

Posted on 2015-12-09, 09:30

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by DAVE86

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi! My FIC-486-VIP-IO is missing the VRM module. Placing the parts should not be a problem. I already prepared the vias for the through hole compnents. All I need is the resitor values on positions R86, R87, R89, R92, R93, R113. Luckily the active components part numbers are silkscreened on the …

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