Re: Full recap of Chieftec CFT-650-14C PSU - I need some info about its electrolytic capacitors

Posted on 2024-03-11, 07:42

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Thank you for these details. In this case I will not do any experiments with polymer caps. The new Samxon low ESR caps I can get are also from not so good GF series, what about Samwha instead? I'll replace Junk-Fu with some descent brand all purpose/regular caps (those are with smaller capacity 1 …

---

Re: Full recap of Chieftec CFT-650-14C PSU - I need some info about its electrolytic capacitors

Posted on 2024-03-11, 06:14

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Teapo SC and Samxon GF are low ESR, you can replace those with Nichicon UPW series or equivalent. Samxon RL and Jun Fu HS are general purpose (note the max. ripple being specified at 120Hz instead of 100KHz in the datasheets), so anything 105C rated should work there. Do try and get some decent …

---

Re: Asus P/I-P55TP4 Rev. 1.21 boot error - no screen, beep code only

Posted on 2024-03-08, 04:28

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In my experience ASUS boards of this era that use Dallas RTC exhibit a really strange behavior when the battery is almost depleted, sometimes not POSTing at all. As soon as I desolder it and do the CR2032 mod they usually start working properly. Also, not long ago I got a P55TP4XE which had a couple …

---

Re: 80386 BIOS image collection

Posted on 2024-03-02, 21:17

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

#: 124 Manufacturer/Identifier: DFI 386-33EC Chipset: ETEQ ET82C491/2A "COUGAR" BIOS/Version: AMI 386 BIOS PLUS 05/05/91 BIOS ID: 30-0400-ZZ1211-00101111-050591-ET/386H Filename 386-33EC.jpg File size 939 KiB Views 62 views File comment 386-33EC

---

Re: 12V rail shorted on ISA card - damaged motherboard. Fixable...?

Posted on 2024-03-01, 19:30

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Moreover, it should go out as a warning to anyone using modern ATX PSUs with a single 12V rail capable of more than 18 Amps that such motherboard trace damage becomes much more likely to occur when a short-circuit happens. For this reason, I prefer to use older PSUs with more reasonable output …

---

Re: Bought these (retro) hardware today

Posted on 2024-03-01, 07:00

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

ubiq wrote on 2024-03-01, 04:23: ASUS ISA-486SV2 (rev 3.10) OMG is that MR BIOS the one that came with the board? If so, please dump the contents! As far as I know no one has been able to find MR BIOS for 486 SiS chipsets!! EDIT: look like someone else has the same board and dumped the BIOS already …

---

Re: ASUS VL/I-486SV2G(X4) REV. 1.8 conversion and jumpers guide

Posted on 2024-02-27, 06:28

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

But i have question… i would like to build an authentic dx4 rig from 1994. Previously i had an early svg0gx4, the bios does not support the lba and the dx4 marked as “p24t” on the bios screen, which is correct, but not nice 😀 I have more sv2gx4, but with 2.x. These boards sold (and mostly …

---

Re: ASUS ISA-486SV2 restoration: L2 cache not working

Posted on 2024-02-27, 03:50

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Success!! CacheDetected.jpg Fixing the KWEX* trace did the trick, and now the board is fully working! Unfortunately I had to remove the VESA slot in order to patch the trace, but seeing the result I think it was worth it: TraceRepair.jpg Those traces are really thin and made soldering the jumper …

---

Re: ASUS ISA-486SV2 restoration: L2 cache not working

Posted on 2024-02-25, 22:59

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

OK, I think I found the problem. As I was examining the board, I noticed what looked like an extremely small gouge near one of the VLB slots. When I applied some IPA with a q-tip a tiny piece of trace that was lifted came off. Looking at pictures I took from when I first got the board, it seems this …

---

Re: ASUS ISA-486SV2 restoration: L2 cache not working

Posted on 2024-02-25, 18:27

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It might be some bad cache chip holders. Either way I would not spend to much effort trying to fix it. Even if you have 256kb of cache you are only going to gain 2% CPU performance at best. If you really want to gain CPU performance upgrade the CPU to a faster one. Motherboard Cache is going to get …

---

Re: ASUS ISA-486SV2 restoration: L2 cache not working

Posted on 2024-02-25, 18:19

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Just to be sure - have you tried to use a contact cleaner on the cache sockets? I had several cases of bad memory/cache because of socket contacts oxidization. It's a good strategy to start with simple things before doing it the hard way. It's a nice board. Hopefully you'll manage to fix it. Yes, I …

---

Re: ASUS ISA-486SV2 restoration: L2 cache not working

Posted on 2024-02-25, 17:45

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

0KB cache means bios tried detecting cache size but determined there is none or malfunctioning - in that case it will not enable Cache at all. Disabled cache will deactivate cache controller TAG inputs. I cant come up with a scenario where behavior you describe would make sense 🙁 How would TAGs …

---

Re: Panasonic/Creative CR-563 CD-ROM Drivers

Posted on 2024-02-25, 02:48

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a CR-562-B here, do they need different drivers? I tried SBCD, as well as SBCDMKE but they don't find the drive. Soundcard is a SB 16 CT 2770 If you insert a CD in the drive, does it try to spin up and detect the disc? I am asking this because at least the CR-563-B model usually suffers a …

---

Re: ASUS ISA-486SV2 restoration: L2 cache not working

Posted on 2024-02-25, 02:29

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

OK, so I ran a few more tests, and what I found is that if the TAG chip is inserted, regardless of whether any of the other 8 cache sockets are populated or not, I get the slightly long POST beep and it hangs on "Starting MS-DOS...". Also I noticed that the table that displays the AMIBIOS settings …

---

Re: ASUS ISA-486SV2 restoration: L2 cache not working

Posted on 2024-02-25, 01:07

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Tried another cpu? Board might always display amount of cache detected, even when its disabled. It not detecting any might mean there is something wrong between cache and main CPU bus. You can look into my signature to see typical ASYNC 486 cache diagram. TAG chip outputs always go back to the …

---

[SOLVED] ASUS ISA-486SV2 restoration: L2 cache not working

Posted on 2024-02-24, 20:12

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

EDIT: read the post below , the problem was due to a broken trace. I've been restoring an ASUS ISA-486SV2 rev 2.4 motherboard, I got it very cheap as it was listed in "not working" condition and was also full of grime, most of the SIMM slots were mangled and broken (as if someone had just ripped out …

---

Re: Quantum Fireball 1.2GB SCSI prices

Posted on 2024-02-12, 16:03

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's probably a model that was used in old Macs or something. Everything related to Mac or Amiga (even if it's just a regular item like a SCSI drive) tends to be absurdly priced.

---

Re: What retro activity did you get up to today?

Posted on 2024-02-08, 17:21

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I was surprised that by replacing BIOS chip all my settings remained intact. Where the hell 486 era boards are storing custom settings? CMOS settings are not saved to the BIOS chip. The motherboard provides a small amount of non-volatile RAM to store these settings (the battery keeps it powered …

---

Re: Future planning for my 486DX4 100 (Upgrading my first PC which I acquired in 1994)

Posted on 2024-02-07, 20:19

by

by TheMobRules

in Marvin \ System Specs

in Marvin \ System Specs

CoffeeOne wrote on 2024-02-07, 20:08: I am curious: For what purpose you would add the US Robotics modem? Just look at that user's post history and you will quickly realize that there isn't any "purpose" to those suggestions. It's almost AI/chatbot level stuff.

---

Re: "Bioteq" chipset

Posted on 2024-02-05, 02:42

by

by TheMobRules

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I tried the ATROM bios from that, but it still gives me the same symptoms as all the other BIOSes I've tried: on the two VLB VGA cards this board wants to work with, I get characters that "drop" or are not properly updated when the screen scrolls. Fuddling with the jumpers on the cards has no …

---