Soldered Bios for GA-7ZX-H v5.1

Only for programmers and BIOS gurus with technical questions.
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darkman
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I have de-soldered the Plcc chip for this board:- a HY29F002T and re-programmed it, unfortunately a track on pin 20 came off the board and is stuck under one of the pins.

It does have another area for a backup bios chip does anyone know - if i put it on that placement would the machine be able to boot or does it need to be in its original location.

If it does is there anyway i could bridge the small gap between the two connections that the track came off of??

Im thinking of ordering two sockets and another HY29f002T or compatible to act as a backup Bios, but i need this answer sorted out first..unless i just go ahead and have a go.

regards
Mark
NickS
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darkman wrote:I have de-soldered the Plcc chip for this board:- a HY29F002T and re-programmed it, unfortunately a track on pin 20 came off the board and is stuck under one of the pins.

It does have another area for a backup bios chip does anyone know - if i put it on that placement would the machine be able to boot or does it need to be in its original location.
Do you have a jumper to select it ? I don't know whether this model does.
If it does is there anyway i could bridge the small gap between the two connections that the track came off of??
You could bridge it with a piece of wire (I use wire-wrapping wire) or even a solder bridge if it's a small gap, but conductive paint (e.g. windscreen heater repair paint) may be safer if the track is likely to peel. I assume you don't have a temperature-controlled soldering iron.
darkman
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This Board has a Bios write protect jumper but no CMOS jumper, and as for the soldering iron, your correct its a bog standard 30watt iron.

I used the chipquik kit to help me out, i'll admit it is good. As for the gap ,its about 1-2mm wide.

It does not have a jumper but take a look at the info below:

c. Dual BIOS Item explanation:

BIOS will auto detect:
Boot From : Main BIOS
Main ROM Type : SST 39SF020
Backup ROM Type : SST 39SF020
Wide Range Protection: Disable(Default), Enable

Status 1:
If any failure (ex. Update ESCD failure, checksum error or reset…) occurs in the Main BIOS , just before the Operating System is loaded and after the power is on, and that the Wide Range Protection is set to “Enable”, the PC will boot from Backup BIOS automatically.

Status 2:
If the ROM BIOS on peripherals cards(ex. SCSI Cards, LAN Cards,..) emits signals to request restart of the system after the user make any alteration on it, the boot up BIOS will not be changed to the Backup BIOS.c. Dual BIOS Item explanation:

BIOS will auto detect:
Boot From : Main BIOS
Main ROM Type : SST 39SF020
Backup ROM Type : SST 39SF020
Wide Range Protection: Disable(Default), Enable

I would imagine that from this explanation, i need to get it in its normal location. What do you think?

regards
Mark
NickS
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Yes, it looks like the main BIOS boot block runs and checks the writability and integrity of the main ROM, switching to the other if there's a problem. If it never starts you're stuffed. My son's got a newer Gigabyte board with a jumper, which is the sensible way to do it.
Maplin's have got a good offer on a soldering station with a temperature controlled iron at present, just a tenner.
darkman
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Nick as i may not be able to connect pin 21 track, how about linking pin21 from the chip to pin20 on the backup bios track,via a thin piece of wire as this is empty. my guess is, as this chip location does not have a chip on it, and it has the same properties as the other one i might be able to get away with it. I just found out its labelled DQ7 Data input/output line (Pin 20 in my last post was incorrect its pin 21, i have the datasheet info on this chip.

regards
mark
KachiWachi
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How much of the trace/pad is destroyed?

If just the pad came off, and you can see the trace, try to remove some of the soldermask over the trace and use a solder bridge to the PLCC pin. If you can see where the trace goes (all on top, no VIA's), then just jumper to whatever it goes too.

If the trace goes under the chip, maybe try putting on a pad from some other old electronic device you have hanging around...just glue it down, then jumper the trace to the replacement pad.

Around here, the girls usually remove/install PLCC chips with a heat gun...
darkman
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How do you apply the solder trace/bridge?

Ive tried connecting the two joints together, but the solder just comes straight off the board, any ideas?

How easy/hard is it to put Plcc sockets onto the board and how thin and what shape do the solder iron aids have to be?

I may just scan part of the board affected and send you the picture, to see if you can help further.

regards

Mark
NickS
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darkman wrote:How do you apply the solder trace/bridge?
You can use a single strand of a multi-strand wire to help bridge the gap, but it's a tricky job.
I may just scan part of the board affected and send you the picture, to see if you can help further
A picture is often useful.
NickS
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darkman wrote:Nick as i may not be able to connect pin 21 track, how about linking pin21 from the chip to pin20 on the backup bios track
I think it would be better to link it from pin 21 to pin 21. That could well work, as it's a data line and should be on a common bus.
sulbert
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OT:
darkman wrote:I used the chipquik kit to help me out, i'll admit it is good.
Where did you purchase it?
darkman
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From www.dannell.net it is based here in the uk
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