Re: identify 486 motherboard

Posted on Today, 05:50

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The lowest grey one essentially disables writeback funciton, making a cache flush every time a write happens as it connects Invalidate pin of an Intel/AMD CPU to read/write strobe. For Cyrix the middle pin is SUSPA which the right connection is toward right, where it is pulled up and suspend is …

---

Re: Does the Yahama YMF 719 (not 718-s) have real OPL3?

Posted on 2021-09-16, 06:44

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

It actually is YMF289 inside there, so OPL3L is more accurate (And it is 44100Hz rather than 48000). There is a very slight pitch difference which you can possibly hear when the two are side by side and there is a small difference in noise type sounds due to sample rate not being same as YMF262.

---

Re: Sound blaster 2.0 CT1350 Troubleshooting - very loud noise

Posted on 2021-09-13, 15:18

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

Without -5V the card should be only producing very very distorted sound as negative half of the signal is clipped off due to lack of the power rail.

---

Re: Bought ViewSonic monitor - image too wide

Posted on 2021-09-12, 18:49

by

by Tiido

in Marvin \ Video

in Marvin \ Video

Congratulations ~ The biggest resource online I know of is this : https://www.repairfaq.org/sam/tvfaq.htm A lot of good info is condensed on these pages.

---

Re: Bought ViewSonic monitor - image too wide

Posted on 2021-09-12, 13:48

by

by Tiido

in Marvin \ Video

in Marvin \ Video

Poking around was worth a shot, especially since previous look inside did restore operation briefly. It certainly seems like a mechanical problem and resoldering various bits in the line and HV stage would probably make a positive difference. The area of interest is mostly confined into the area …

---

Re: Bought ViewSonic monitor - image too wide

Posted on 2021-09-11, 18:29

by

by Tiido

in Marvin \ Video

in Marvin \ Video

That looks like a problem around what is called S correction. One of the fat capacitors seen on the last insides photo is responsible for correcting for it though the way things work is that if there's a problem the sides should be expanded rather than compressed... It is worth trying to exercise …

---

Re: Bought ViewSonic monitor - image too wide

Posted on 2021-09-11, 12:47

by

by Tiido

in Marvin \ Video

in Marvin \ Video

The fault is likely to be in the zoo near the flyback transformer, probably the larger components. The closed up box attached to the neck is only video amps etc., there won't be anything that affects geometry there. Can you take a photo of the image and perhaps some of the main board itself ?

---

Re: Bought ViewSonic monitor - image too wide

Posted on 2021-09-11, 11:37

by

by Tiido

in Marvin \ Video

in Marvin \ Video

That seems like some capacitor in the deflection circuitry is causing it, possibly a cold solder joint since you managed to get good image. If you are willing, run the thing open, and use some non conductive thing (plastic rod equivalent) and tap various bits and see if you can find the culprit.

---

Re: Sound blaster 2.0 CT1350 Troubleshooting - very loud noise

Posted on 2021-09-09, 18:59

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

The "thinking noises" are basically normal on these early SB cards. Creative didn't do a good job on the design on analog side. You can replace some of the power supply capacitors for modern types but it will only soften the problem, to cure it there's a need for substantial modifications to reroute …

---

Re: PCB card-edge connector gold plating

Posted on 2021-09-09, 12:03

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Gold and tin freely amalgamate, upon contact the gold is diffused into the tin. This is the mechanism by which the connector is damaged, losing its gold plating and getting exposed to oxidation effects. This is something I see causing problems time and time again in stuff like MegaDrive + MegaCD, as …

---

Re: Does the Yahama YMF 719 (not 718-s) have real OPL3?

Posted on 2021-09-08, 18:06

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

The ones I made (see signature for more info) /shamelessplug 🤣

---

Re: Does the Yahama YMF 719 (not 718-s) have real OPL3?

Posted on 2021-09-08, 16:03

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

All of the YMF71x chips have OPL3 inside them, regardless of the OPL logo that is seen on some of the chips. (there are OPL3 chips with and without the logo for example, it is purely aesthetic thing)

---

Re: Good soundcard for Windows 2000

Posted on 2021-09-07, 17:12

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

I'm most pleased with my ESI Juli@ sound card, works on 98SE/ME/2K/XP and newer stuff too. Has ASIO and other goodies such as 24/192 support too.

---

Re: The worse placement of capacitors on motherboards

Posted on 2021-09-06, 16:02

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have one PIII board where capacitors block the ATX power connector latch. I ended up putting shorter caps there so that it wouldn't be such a big problem.

---

Re: Talking to ISA / PCI?

Posted on 2021-09-06, 10:28

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Win9x direct hardware access depends on whatever the drivers do. By default all IO is open but drivers can trap the IO accesses and take over things and many drivers do as part of hardware virtualisation. Timer, IRQ and DMA controllers are handled this way aswell as video stuff. Some sound card …

---

Re: PCB card-edge connector gold plating

Posted on 2021-09-03, 21:03

by

by Tiido

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

HASL is going to ruin the slot it is put into (the gold plating in the slot is going to be damaged), if you're gonna use it in that one slot it should not be moved into any of the others.

---

Re: What is the cloudiness that can appear on I/O brackets?

Posted on 2021-09-02, 04:36

by

by Tiido

in Marvin \ Video

in Marvin \ Video

I'm not sure what it is but when I have had similar things I have just used pencil eraser on it and it is gone afterwards.

---

Re: Playback hardware MIDI and sound effects simultaneously

Posted on 2021-08-31, 16:12

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

SC55 should have a master volume control that can be changed by a sysex or some other way (using a special MIDI file you play as part of initialisation), but I don't know any further details...

---

Re: Playback hardware MIDI and sound effects simultaneously

Posted on 2021-08-31, 13:25

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

I guess you have maximized the master volume on the sound card ? (I'm not sure if you meant that by speakers volume, or the actual knob on the speakers)

---

Re: Creative Phone Blaster CT3110 - need capacitor info

Posted on 2021-08-31, 01:52

by

by Tiido

in Marvin \ Sound

in Marvin \ Sound

It is a 47pF capacitor, probably a C0G / NP0 type. Function of such small capacitors in that spot seem to be timing fixes for increased stability (slightly delaying a signal or filtering out some glitches etc.). The card probably works without them but may have random problems.

---