VOGONS


How to fix your dead on-board floppy controller

Topic actions

Reply 62 of 79, by feipoa

User metadata
Rank l33t++
Rank
l33t++

here's a good starting point, http://www.seekic.com/

But you are in luck, there is one on ebay, http://www.ebay.ca/itm/222309916159

Ultimate 486 Benchmark | Ultimate 686 Benchmark | Cyrix 5x86 Enhancements | 486 Overkill Graphics | Worlds Fastest 486

Reply 63 of 79, by Synoptic

User metadata
Rank Member
Rank
Member
feipoa wrote:

here's a good starting point, http://www.seekic.com/

But you are in luck, there is one on ebay, http://www.ebay.ca/itm/222309916159

Thanks !
I ordered the one on ebay,

Reply 64 of 79, by feipoa

User metadata
Rank l33t++
Rank
l33t++

Just one? I would have bought 3 and made him an offer for half price.

Ultimate 486 Benchmark | Ultimate 686 Benchmark | Cyrix 5x86 Enhancements | 486 Overkill Graphics | Worlds Fastest 486

Reply 66 of 79, by Synoptic

User metadata
Rank Member
Rank
Member

News update : Well, I think I fucked up. I misplaced the chip the first time so I had to de-solder it. I may have damaged it.
Floppy still fails, COM PORTS are showing, now, but they're showing even if they are set to disabled in the bios.

I have ordered 3 other chips, lets see how it goes.

Reply 67 of 79, by feipoa

User metadata
Rank l33t++
Rank
l33t++

Did you make the seller a discounted offer?

You only get one try to solder these on. It would be very difficult to desolder the whole chip such that it is reusable. I'm lucky I got mine on right the first time. Also, you might want to try some thin solder, like 0.3 - 0.5 mm. This way, you might be able to flow new solder onto the pins instead of relying entirely on the old solder. Me relying on the old, existing solder, is what made for the contact issues. Unfortunately, I only had 0.8 mm solder at the time, but some thinner stuff is on order.

Here is an example of the good stuff, http://www.ebay.ca/itm/351777770333?_trksid=p … K%3AMEBIDX%3AIT
But if you are a cheap skate risk taper, here's another option, http://www.ebay.ca/itm/181944537723?_trksid=p … K%3AMEBIDX%3AIT

Ultimate 486 Benchmark | Ultimate 686 Benchmark | Cyrix 5x86 Enhancements | 486 Overkill Graphics | Worlds Fastest 486

Reply 68 of 79, by Synoptic

User metadata
Rank Member
Rank
Member
feipoa wrote:
Did you make the seller a discounted offer? […]
Show full quote

Did you make the seller a discounted offer?

You only get one try to solder these on. It would be very difficult to desolder the whole chip such that it is reusable. I'm lucky I got mine on right the first time. Also, you might want to try some thin solder, like 0.3 - 0.5 mm. This way, you might be able to flow new solder onto the pins instead of relying entirely on the old solder. Me relying on the old, existing solder, is what made for the contact issues. Unfortunately, I only had 0.8 mm solder at the time, but some thinner stuff is on order.

Here is an example of the good stuff, http://www.ebay.ca/itm/351777770333?_trksid=p … K%3AMEBIDX%3AIT
But if you are a cheap skate risk taper, here's another option, http://www.ebay.ca/itm/181944537723?_trksid=p … K%3AMEBIDX%3AIT

I did make a discounted offer.
I have small solder, no worries about this.
I ordered 3 spares ;P
Desoldering it with my hot air station really went well though. It's a shame that I didn't align it properly. In fact, it was aligned, but I moved it a bit more on the right to center it without cheking the aligment of the perpendicular pins. It was late at night and I was too excited and tired at the same time.

Oh well, lesson learned.

Reply 69 of 79, by Synoptic

User metadata
Rank Member
Rank
Member

Update :
I received the new chips and replaced the one I had previously replaced. Results are the same : Floppy still fails, com ports are showing eventhough they are not enabled in the bios.
However, I discovered that changing the com ports and LPT settings would sometime change the POST information to something different than the settings.

Let me explain. If I disable everything, on the POST screen, I see LPT disabled, COM1 = 3E8, COM2 = 2E8
If I change some setting (didn't note which one) like disabling LTP, changing COM1 to 3F8 and COM2 to 2F8, the POST screen will report COM1=NONE, COM2=2F8 and LPT still disabled.

Which make me thinks that maybe the chip is working but revision is important for compatibility with my board revision maybe.
I had a

UMC8663BF
9614-BXT
ZM3652

that I replaced with :

UMC8663BF
9647-BXA
VZAE66

Reply 70 of 79, by feipoa

User metadata
Rank l33t++
Rank
l33t++

UMC8663BF - both with BX after the datecode. I would bet these are pretty identical. It sounds to me like something else is going on. Can you remind me, is your issue with the serial ports or floppy controller? If your issue is serial port, then perhaps the serial port chip is bad. It is the UM8667 chip.

I also have a board which has a working floppy controller, but the serial ports do not work. It is something that I will need to fix at some point. Stay tuned.

Ultimate 486 Benchmark | Ultimate 686 Benchmark | Cyrix 5x86 Enhancements | 486 Overkill Graphics | Worlds Fastest 486

Reply 72 of 79, by feipoa

User metadata
Rank l33t++
Rank
l33t++

Is it possible that some of the pins you soldered did not full contact? That was my issue. Another idea might be to try a different BIOS from another motherboard which uses the same chipset and has the same SUper I/O on board. Can you remind me what is the motherboard in question?

Ultimate 486 Benchmark | Ultimate 686 Benchmark | Cyrix 5x86 Enhancements | 486 Overkill Graphics | Worlds Fastest 486

Reply 74 of 79, by feipoa

User metadata
Rank l33t++
Rank
l33t++

I suppose you could try replacing the southbridge...

Ultimate 486 Benchmark | Ultimate 686 Benchmark | Cyrix 5x86 Enhancements | 486 Overkill Graphics | Worlds Fastest 486

Reply 76 of 79, by Synoptic

User metadata
Rank Member
Rank
Member

Ok, 4 years later, I decided to dig the motherboard back and tackle the issue.
From reading carefully this thread, I see that @Feipoa's issue was bad contacts.

I would like to get a list of pins to test for voltage. Where can I find the chip's pinout ? @Feipoa, would you help me tackle this again ?

Reply 77 of 79, by feipoa

User metadata
Rank l33t++
Rank
l33t++

Hard to say for sure if it was bad contacts or a bad floppy controller IC. Use a multi-meter to make sure all the leads on the floppy controller IC make contact with the solder pad. If not, then reflow it. Once all leads are sure to be making contact, if it still doesn't work, then perhaps swap out the floppy IC like I did.

Ultimate 486 Benchmark | Ultimate 686 Benchmark | Cyrix 5x86 Enhancements | 486 Overkill Graphics | Worlds Fastest 486

Reply 78 of 79, by pentiumspeed

User metadata
Rank Oldbie
Rank
Oldbie

Hi Feipoa,

The way the solder joints are like this is too cold soldering iron or soldering station's temp too low, or soldering iron's tip dull. Each pin should be touched and wait bit longer to insure it is completely melted then move on to next.

Second, not having tube of no-clean flux can cause this. I coat the SMD joints in this during soldering, helps to keep solder from corroding during soldering. When done, clean up the mess with 99% alcohol.

Cheers,

Great Northern aka Canada.