Chaintech 7AJA2

[Alex Atkin UK]

Are the caps likely to be the cause of the problem for this board?

It just suddenly stopped POSTing, it might have been underpowered on the PSU as I hadnt realised the PSU was only rated at about 130W.

[bushytails]

Re: Chaintech 7AJA2

g-luxons often fail with no signs... I have a couple boards with them in the recap pile.

--Randy

[Rainbow]

Re: Chaintech 7AJA2

I've had 7AJA2-E board that had one mosfet shorted and flash ROM chip missing. Replaced mosfet with the exact type, put in a flash ROM flashed with correct BIOS and it works.

[Alex Atkin UK]

Re: Chaintech 7AJA2

I actually had to replace this board with an E model I had but that one doesnt like the Duron much that im using in it. It could very well be that THAT board is failing due to caps too though as I bought the E first, its certainly running games a LOT slower than the above board did before it died.

Incidentally, I also have an ECS K7S5A which runs fine apart from the onboard sound (the bass drops out when you turn the volume up). However a friend is taking it to University with him so I don't really have time to worry about recapping it as I want to practice on the Chaintech first as its the only board thats not actually functioning right now.

Based on your experiences with the K7S5A, if it goes off to Uni with my friend and the caps go - how likely is it to take other components with it? I realise you can't be 100% sure, theres always a risk - but the risk would seem greater that I screwup recapping it due to trying to rush it before I have had time to think about it and practice on some old boards I no longer care about.

Tricky isnt it.....

[Rainbow]

Re: Chaintech 7AJA2

Lowew performance probably means that you have something configured differently.
When caps fail on K7S5A, the mosfets are often damaged too. Then it's not so easy to repair and it could damage the CPU too.

[MD Willington]

Re: Chaintech 7AJA2

Recap the K7S5A now to avoid the headache I've experienced...

MD

[Alex Atkin UK]

Re: Chaintech 7AJA2

I know its a long shot but do you know what caps it has that need replacing without me having to dissasemble the machine? Its currently in use and would be a REAL pain.

Also, sites such as rswww.com have MUCH too many capacitors, I have no clue what im looking for in order for it to be the right tolerance vs cost effective. For example I was looking for 2200uf capacitors for the Chaintech (I want to try that first as its already dead and even better, not currently in a case) but theres TONS, some would work out more expensive than buying a new board, some a lot cheaper.

If anyone has a few minutes to help I would really appreciate it although I feel kinda guilty asking so many questions all at once like this.

It sounds like once this is sorted you guys will have saved me a small fortune, its a shame you arent in the UK so I can just send all the boards to be sorted at once. I do wonder how many of my reliability problems in the past were simply failing caps.

[AK0R]

Re: Chaintech 7AJA2

See my answer at:
https://www.badcaps.net/forum/showthread.php?t=818

There are other posts that indicate the preferred manufacturers and series; use the "Search" function to find them.

RS Components has been a good overseas supplier. Knowing the capacitance, voltage rating, temperature rating, and physical size, and that you want low ESR, you should be able to find suitable replacements that won't break your pocketbook. If you need further help, let us know what's on the board, and your proposed replacements, and we can give you a yea or nay.

[Alex Atkin UK]

Re: Chaintech 7AJA2

How important is the temperature rating, seeing as these caps most DEFINATELY wont be subject to such high temperatures.

[AK0R]

Re: Chaintech 7AJA2

How important is the temperature rating, seeing as these caps most DEFINATELY wont be subject to such high temperatures.

You want to use 105°C parts, for sure. Internal case temperatures can be much higher than ambient, and component temperatures higher yet. The temperature rating is component temperature, not case or ambient. Why don't you post the following: quantity, capacitance, voltage rating, and physical dimensions for all caps on the board, and we can recommend appropriate replacements.

[willawake]

Re: Chaintech 7AJA2

http://rswww.com/cgi-bin/bv/initSess...63994&store=uk

check the link for what you want. Panasonic FC will be perfect for your needs.

[Alex Atkin UK]

Re: Chaintech 7AJA2

Thankyou thats super helpful (guess thats the super in super moderator?).
I also see now how RS list "low impedance" in the title, I didn't notice that before.
I will have a go repairing the Chaintech with these and see how it goes.