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Saturday 23 October 2010

Motherboard faulty bad capacitor repair

We would like to thank the original author of this review at www.punj.co.uk for granting us permission to publish this  particular blog content. The original contents of the review can be found at http://www.punj.co.uk/punjwebfiles/electronics/mbbadcap.html 

Motherboard faulty bad capacitor repair

On this page we are going to show you an example of bad capacitors on a computer motherboard. We will discuss the motherboard specification, the symptoms of this problematic board and the final repair outcome of this motherboard.

BioStar Motherboard

We were recently given a computer which would give occasional BSOD (Blue screen of death) and always provided grainy poor quality video. The computer would also when shutting down not completely switch off. Although the computer was switched off the power LED would remain on and you could then not switch the computer back on. The only way to switch the PC back on was to un-plug the PC from the wall socket and plug the supply back on. The PC would then boot up again until the next shutdown. Any good graphic applications would always cause a BSOD (Blue screen of death) using either the internal graphics GPU or the use of any add on graphics card.

On opening the computer casing we noted that the motherboard was a Biostar GeForce 6100-M9 with an AMD Athlon 3000+ 64 bit socket 939 CPU. The main memory ram installed was 1GB with a Western Digital 80GB IDE hard disk drive. Apart from the above symptoms the computer ran fine.

Straight away we noticed when looking at the main motherboard that quite a few of the electrolytic capacitors looked bad. Actual component testing on today's modern circuit boards can be quite difficult without test instruments. The use of specialist test meters and equipment is the only way to satisfactorily test components.

Not everyone will have access to the specialist test equipment. We can however sometimes assume failure of some components by visually looking at these components.

Visual checking of a capacitor to determine failure is one example where an electrolytic capacitor will look different to a good electrolytic capacitor on a circuit board.

For a basic understanding of what a capacitor is and what it does you can either google for more information or you can visit our web page http://www.punj.co.uk/punjwebfiles/electronics/basicelectronics.html 

Below the image on the left shows what a good capacitor should look like. On the right image we show an example of a bad capacitor. You will notice that the bad capacitor casing on top is bloated where as the good capacitor on the top is completely flat.

Good Capacitor     Bad Capacitor

Image on the left shows a Good Capacitor     ----     Image on the right shows a Bad Capacitor

You may also notice that a bad capacitor has leaked from the top or bottom with its electrolytic content. Capacitors can also go bad and show no visible signs. The only way to test a capacitor which shows no visible signs of failure is to measure the capacitors ESR and capacitance value using an ESR meter. You can read our review on a great budget meter called an ESR Micro which can be used for the correct method for testing capacitors on http://www.punj.co.uk/punjwebfiles/electronics/microesr.html

On our motherboard we had five 3300uf 6.3V capacitors located near to the CPU and two 1000uf 6.3V capacitors elsewhere on the board showing the bulging effect of a bad capacitor.

bad caps near cpu

As you can see on the image above the five capacitors which are next to the CPU heat sink are bulging with some signs of electrolytic leakage.

It is advisable prior to removing the capacitors to make a sketch or take photographs of where the capacitors are located on the motherboard. The last thing you would want is to forget which capacitor came from which location on the motherboard. You certainly don't want to be putting in the wrong capacitors in the wrong location of the motherboard. You must also take your time and double check each task when carrying these procedures.

Removing capacitors on modern motherboards can be quite tricky. Most modern motherboards are made of multiple layers interconnecting each layer. Care must taken that the layers not visible on a motherboard are not damaged when soldering or de-soldering. When removing these components the soldering iron must be clean and hot enough to melt the solder but not to hot that it will cause heat damage to the circuit board tracks which may be visible or located within the un-visible layers of the board. A good tip is to heat the lead of the capacitor and wiggle and pull on one side then heat the other lead and do the same to that. Eventually the capacitor will come out. The other problem you may encounter is once the capacitor has been removed the component hole is completely blocked with solder. Our tip to unblock these holes is to apply some more solder on the blocked hole and then use a solder sucker tool to suck the solder out of the hole. If you find that the solder sucker is not totally unblocking the component hole then pushing a stainless steel needle into the hole while holding the hot soldering iron on to the blocked hole sometimes helps. The hot solder should not stick to the stainless steel needle and therefore this tip should work.

Below we provide an image of the motherboard with the capacitors removed.

Caps removed

Once the capacitors have been removed you should inspect the motherboard with a magnifying glass to ensure that no solder that should have been removed is shorting the board. If all looks well then you are ready for the next procedure.

If you look at the image above, of the motherboard with the removed capacitors you will notice where the capacitors came out there is a symbol of a circle with one side coloured white. This white coloured area shows us the polarity of the capacitor to be negative on this white coloured side. The polarity of the capacitor is very important for the correct function of the capacitor.

On our motherboard we chose our replacement of capacitors manufactured by Panasonic and Nichicon. We wanted to ensure our replacement capacitors were sourced from reputable manufactures. We chose the same value capacitance and voltage for our replacement capacitors. You can use higher voltage capacitors but you should ensure that the capacitor leads are not to thick to put back into the motherboard component hole. 
Once the new capacitors have been put into the motherboard always double check before soldering that the correct values have been used. It is quite easy to confuse and mistakenly use a 100uf capacitor instead of the correct value 1000uf. Also check that you have inserted correctly the polarity of the capacitor.

new caps on mb

Above you will see an image of the motherboard with the new replaced capacitors.
On completion of the soldering task you may want to clean the excess flux deposits left behind by the soldering. We normally use a cotton bud dipped into alcohol which works fine for us. Now is also a good time to re-check the new capacitors to ensure that the correct values have been used and that the motherboard is clean and ready for re-installation.

On re-installation of the motherboard into the PC tower case we ensured that all the add on cards and memory went back into the same slots as originally found prior to stripping out the motherboard. If you do end up using a different slot for your add on card or memory you may find that the PC will not re-boot until you have cleared the CMOS and loaded the default factory settings. Your motherboard manual should help to locate the correct jumper on the motherboard to clear CMOS if you find you have a blank screen.

For us the motherboard switched on straight away and booted straight in to the XP operating system with out any problems. We used Everest to stress test our repaired motherboard for two hours without encountering any problems.

On completion we decided to test the faulty removed capacitors using the ESR Micro V4 for measuring the capacitance and ESR readings.

A good 3300uf capacitor should give us a measured capacitance reading of the same value subject to the manufactures tolerance of about 10% either side of the tolerance value. We would also expect the ESR measured reading to be approximately 0.02 ohms. Testing the removed bulging capacitors gave us typical measured readings of 138uf capacitance and an ESR measurement of 36 ohms for the 3300uf capacitor. This clearly showed that these capacitors were faulty and if left in their current state they could have caused more severe problems to other components on the motherboard.

In our final conclusion we can say that replacing the bad capacitors on this motherboard completely resolved our previous problematic issues. Our motherboard seems also quicker in load times and faster over all.

The whole cost of the five 3300uf 16V and two 1000uf 16V capacitors was under £6.00 GBP including shipping. The whole task of replacing the capacitors took approximately forty five minutes.

We hope our readers have enjoyed this article on replacement of faulty bad capacitors on computer motherboards and will come back to www.punj.co.uk for our views on more technological products.

punj

Saturday 9 October 2010

Review on the MCUmall USB-PRO-GQ-4X programmer

We would like to thank the original author of this review at www.punj.co.uk for granting us permission to publish this  particular blog content. The original contents of the review can be found at  http://www.punj.co.uk/punjwebfiles/electronics/usbprogq4x.html

Today we are going to review the latest EPROM / EEPROM MCUmall True-USB PRO GQ-4X Willem Programmer. We will provide information on what the manufacturer of this product claims and how we recently successfully used this product to repair a failed bios on a laptop. Our review will be based on our experience on ordering this item direct from the manufacturer and its ease of use.



So what is this EPROM programmer. EPROM chips are found in numerous hardware which store essential data.

An example of this is the bios chip on all modern computers and laptops. On computers and laptops these EPROM chips will be either installed within a socket or soldered directly to the motherboard.

The bios is the first part of software code to run when you switch on a computer. This code gives instructions for the power on self test (post). This self test checks and ensures that the computer has all the required parts eg disks memory etc and that they function.

We originally had a need for a product like this for re-programming bios chips which are found in computer / laptop motherboards. We did our research like most on the Internet on what products are available, their ease of use as stated on the marketing literature and the cost of the item inclusive of shipping to our United Kingdom premises.
Most products we came across seemed very expensive and lacked the support of future software upgrades for the programmer. Also we noted that these products in most of the cases lacked good customer reviews or seemed to technical for ease of use.

One company who not only manufactures this type of product but also sells their products direct world wide is MCUmall Electronics Inc.

MCUmall Electronics Inc
is a company based in Canada which seems to have a very good reputation for the manufacture of specialist electronic hardware and software. In our own personal opinion they lead in providing budget affordable good quality hardware, the USB Pro GQ 4X would be a good example of this.

So how did we rate them on getting product information, ordering, shipping and after sales customer service on this product.

We first read their marketing literature on their web site about their EPROM programmers on this site
http://www.mcumall.com/comersus/store/comersus_dynamicIndex.asp
Their web site is simple with precise information on the products they deal with. They also have a dedicated support site which is regularly visited by their staff offering advice on not only their products but other manufacturer devices to.
After much research on this product we placed an order for the True-USB PRO GQ-4X Willem Programmer
The ordering process was straight forward like most online purchases. The order was placed in February 2010 and the cost including shipping was £84.93 GBP on our chosen payment method. We were sent emails confirming our order and shipping details.

The item took 10 working days to arrive and was well packed. The package arrived with the following contents.
1 - One True USB Programmer Series GQ-4X
2 - One USB cable, and one installation CD with the latest software and PDF user manual.
3 - One PLCC32-DIP32 Socket Adapter.
4 - One PLCC32-DIP28 Socket Adapter.
5 - One FWH+LPC Adapter.
6 - One PLCC IC extractor.

We recently acquired an Fujitsu Amilo Laptop which had a corrupt bios. The laptop was completely dead with no activity or lights on. In the past we have recovered bad bios corrupt code by using a method known as crisis disk recovery.


Most modern computer bioses can be recovered by using a crisis disk whether this be via a floppy or usb disk media. On some computers however when the bios boot tables become corrupt this can be problematic as this normally requires the bios chip to be manually reprogrammed or replaced. As the laptop showed no signs of life whats so ever we had to open the laptop casing up to get to the bios chip. For a change this laptop was quite easy to work on. The laptop bios was a plcc32 chip part number A29040AL-70.


bios



The laptop bios chip was also placed in a socket which meant it could easily be taken out. On some motherboards the bios chip can be soldered onto the motherboard which then requires the chip to be un-soldered for reprogramming or replacement. Bios eeprom programmers can be purchased with test clips that can be clipped to the chip but these are quite expensive to buy. For those who don't have an eeprom programmer the bios chips are quite cheap to buy of fleabay. The sellers can also send the chips pre-programmed with the bios code of your choice. This type of repair can be very expensive and some manufacturer support engineers sometimes replace the motherboard rather than the cheaper solution of repair or replacement of the chip. In some cases this repair can cost up to or more than the original computer itself.

Using the MCUmall True-USB PRO GQ-4X Willem Programmer device.

Using the MCUmall True-USB PRO GQUSB lead. MCUmall regularly update their software to support additional chips. If you find that your EPROM chip is not supported you can visit MCUmall support site where they will in most cases help you to add your un-supported chip to the software database.

In our review our corrupt bios chip was a plcc32 chip part number A29040AL-70. We ran the programmer software on our test computer and followed the simple instructions. The programmer software on our test machine was Revision 5.02b.
Once the software has opened you click on the "Device" tab to search for your device chip. Our bios chip was supported by the programmer software. The programmer software will then ask you to place your EPROM chip into the programmer. Clear instructions are given on placement of the chip to the programmer with regards to orientation or use of any adapter that maybe required. In our case the software asked us to place our chip in the PLCC32-DIP28 Socket Adapter and then lock the device in to the programmer ZIF socket.
You can then carry out various tasks such as read, erase, blank check, write and verify.
We already knew that the data code on our bios chip was corrupt so our first step was to delete the original code within the bios chip. We then got a copy of some good bios code from the faulty laptop manufactures web site and used this good bios data code to "write" to our bios chip. The programmer software will also verify that the new bios code has been correctly written and read from the chip.

And thats it. The process of updating our corrupt bios code was as simple as mentioned above.

To confirm that our bios chip code had been written correctly we put our bios chip back into our faulty laptop and bingo the laptop had come back to life.

In our final conclusion to our review we can honestly say that our dealings with MCUmall and the purchase of their latest MCUmall True-USB PRO GQ-4X Willem Programmer has overall been a good experience.

The company dealt with our sales order with out any prior knowledge that such a review would be made by ourselves. We have based our review solely on our experience with this great budget product with out any external influence whats so ever.

We hope our readers have enjoyed our review and will come back to www.punj.co.uk for our views on more technological products. 
 
punj