A600 Capacitor Replacement

[kipper2k]

Orders been shipped so hopefully i get them by next Friday (doubt it though ) Ordered the 44, 52, 68, and 84 pin sockets and the hot air nozzles that i need. The general idea now is to remove all the PLCC chips as well as the caps and put the PLCC chips in the sockets. I have about 6 x A600 boards so i hope to use this as a testing board for chips.

In order to remove the PLCC chips you gotta have a hot air rework station and the nozzles. They are not expensive. I will post all the info and where to get all this equipment later today, after the game .

For removing the capacitors themselves you can either use a fine tipped soldering iron and pop one side at a time being careful not to tug at it or use a small nozzle. ( i prefer the soldering iron.. too much heat and a nozzle can puncture the cap and boy oh boy they stink.. its a stink that lingers lol).

later...

[prowler]

Hi kipper2k,

Great work!

Can we expect to see the introduction of a "kipper2k/EAB Amiga motherboard capacitor and PLCC chip socket overhaul service" any time soon?

prowler

[kipper2k]

I like doing this kind of stuff... i find it more fun sometimes than actually playing games. There are not a lot of these custom chips left kicking around so the main reason for me doing this is trying to salvage the chips from broken boards, testing them on a test board and then make them available for people.

So if you have an old a600/A1200 board that you are going to chuck in the bin give me a yell and i will rescue it (if shipping costs are not that bad). Shipping charges from UK to Canada are not that bad for a 2 week delivery so its worth it.

I will post some tips on soldering with this little project too, provided i can get the missus to hold it for me lol. (haha, the camera!)

[kipper2k]

k, heres more info...


if you want to tackle something like removing PLCC's etc then you will need the right tools. Having the right tools make it easy to do with just a little practice. I'm sure most of you have old cards kicking around that you can practice on without the fear of breaking anything.

First thing you need is a Hot Air Rework Station. This one below is perfect. its cheap, has all the bells and whistles that we need and has a pretty good temp control system on it. (same as mine)


http://cgi.ebay.co.uk/SMD-Rework-Sol...1%7C240%3A1318

_______________________________

Now you need a few nozzles that will allow you to remove the PLCC chips quickly without overheating them and not breaking any legs or traces. Heres a place i found that sell them at a pretty good price and for those of you in England/Europe cheap postage. The A600 uses all of the following sized PLCC's

http://stores.ebay.co.uk/The-Allenda...QfsubZ18840470

Aoyue 1135 (44 pin PLCC)
Aoyue 1136 (52 pin PLCC)
Aoyue 1137 (68 pin PLCC)
Aoyue 1138 (84 pin PLCC)
__________________________-

Heres a suction pen you GOTTA! have, makes life so easy lifting the chip off the board once the solder has melted. Dont forget, look around for the best prices.

http://www.alibaba.com/product-gs/20...ction_Pen.html


more later...

[prowler]

Hi kipper2k,

Now it's beginning to sound more like the "kipper2k/EAB Amiga motherboard capacitor and PLCC chip socket overhaul provisions and training service".

Great work!

prowler

[kipper2k]

Thanks Prowler

Heres the URLs to find the PLCC sockets that would be mounted on the board once the chip has been removed. I will provide the links to digikey to save people stumbling around the digikey component search pages.

I was able to find all but the 52 pin socket on fleabay. The prices are definately cheaper on fleabay so look around before you commit.

44 pin
http://search.digikey.com/scripts/Dk...ame=AE10071-ND

52 pin
http://search.digikey.com/scripts/Dk...ame=AE10072-ND

68 pin
http://search.digikey.com/scripts/Dk...ame=AE10073-ND

84 pin
http://search.digikey.com/scripts/Dk...ame=ED90018-ND


I think that covers all the parts that would probably be the mail ordered stuff, the rest should all be local purchase..

Thats all for now

[Loedown]

Greetings,
I would only add one thing, before playing with valuable Miggy in attempts to take of PLCC, practise first on not expensive broken PC parts.

Paul

[AlfaRomeo]

@kepper2k

Many thanks by your guide buddy,
this was the information that I needed about soldering tools to begin playing around with PLCC´s

[Secret Vampire]

@kipper2k

Do you have an ESR (Equivalent series resistance) meter? Measuring the ESR and leakage (Electrical, though leaky capacitors tend to get hot, leading to physical leakage, and in the case of larger high voltage ones explosive leakage :P ) will tell you much more about the state of a capacitor than measuring the capacitance will. Capacitance can be within tolerance, yet the cap can still be leaky or have high ESR, which will impair its performance in the circuit significantly.
Plus, you can test ESR in circuit, useful if you have a board with dozens of caps that you don't really want to replace to find out if they're bad.

[kipper2k]

Hi Secret Vampire,

I only have a multi function meter so its a case of actually measuring the capacitance once the cap has been removed from the board (i have my eye on a PC scope). If i had the meters to measure them properly without removing then that would be ideal. Once they get old they can cause compound errors so i think its best as everyone does to physically remove them. Its not a big job to remove them so i think thats the safest route. Especially as they are gettting close to 15+ years old.

[kipper2k]

I received my order from Digikey (very surprised).. i am still waiting for the 44 pin sockets but here is an update of where I'm at now. All the caps are back on, the 52 pin PLCC sockets are back on and the empty sockets ae prepped.

Heres a pic, if you want to see see the hires pic then click on the link below. (ignore the whitish colour by Gayle, the board is clean, its just a trick of light with the camera).


http://www.kipper2k.com/images/capsonhires.jpg




I'll post some info when i am putting the 44 pin sockets back on, hopefully Monday i'll receive the missing parts.

[e5frog]

I decided to do a complete re-cap of my A600 as well, I'm having startup-problems but it starts eventually and then work flawlessly. I have detected some leakage on the motherboard as you can see in this thread:

http://eab.abime.net/showthread.php?t=54306

Pictures:
http://eab.abime.net/showpost.php?p=691777&postcount=24

Not being too keen on paying some $25 shipping I decided to find the parts at Elfa instead. It's located in Scandinavian countries and a few other European countries, I think they also have some sort of world service.
https://elfa.se/elfa3/index.jsp

If ordering from Digikey this is the minimum amount I had to order for one set:


From Elfa I was able to order the exact amount and as there's a store in the nearest town I can pick it up tomorrow.
These are the order numbers and amounts, you can simply copy this, save as a text file and upload it using the "Own list" option in the order form:

67-309-98 4
67-323-74 5
67-309-97 2
67-309-94 4
67-044-14 2
67-228-21 2

In Sweden the sum is 77.11 SEK with tax, about 8.2 EUR or US$ 10.6... When I logged in as European Union the price tag was 19.58 EUR with the 10 EUR shipping cost (Letter Export shipping option)



It's an alternative at least, good luck.


BTW: To prolong the life of electrolytic capacitors it is recommended - before soldering them to the board - to connect them to a variable power source + to +, - to - and then start at a low voltage then slowly increase it until you reach the printed voltage value and then slowly decrease it again. I read it on an information page of another electronics company.

[Zetr0]

Hiyas Kipps

Originally Posted by kipper2k

///
A600 parts list.....

4 x PCE3008CT-ND CAP 10UF 25V HA ELECT SMD
5 x PCE3009CT-ND CAP 22UF 25V HA ELECT SMD
2 x PCE3006CT-ND CAP 47UF 16V HA ELECT SMD
4 x PCE3002CT-ND CAP 100UF 6.3V HA ELECT SMD
2 x P5521-ND CAP 1000UF 10V ELECT NHG RADIAL
2 x P5141-ND CAP 470UF 16V ALUM LYTIC RADIAL

A1200 (Please verify, markings on my caps are a little obscure but i believe these are correct)

3 x PCE3008CT-ND CAP 10UF 25V HA ELECT SMD
5 x PCE3009CT-ND CAP 22UF 25V HA ELECT SMD
2 x PCE3006CT-ND CAP 47UF 16V HA ELECT SMD
4 x PCE3002CT-ND CAP 100UF 6.3V HA ELECT SMD
2 x P5521-ND CAP 1000UF 10V ELECT NHG RADIAL
2 x P5141-ND CAP 470UF 16V ALUM LYTIC RADIAL

to add my own to this

A1200 Cap Replacement

Electrolytic 

Ammount          Value      Voltage Rating
4                100uf       6.5
2                47uf        16
4                22uf        25    
3                10uf        15


2                1000uf      10
2                470uf       16

        
A4000    CAPACITORS AND IC REPLACEMENT 

AMT    NAME        GROUP        VOLTAGE RATING

2    470UF        TH-CAP         16V
1    100UF        SMD-CAP        6V
10    47UF        SMD-CAP        16V
5    22UF         SMD-CAP        16V
1    10UF         SMD-CAP        35V
2    4.7UF        SMD-CAP        35V
    
1    74LS174      SOJ-IC        5V - Hex D-type flip-flop with reset; P.E.T.
1    74F245       SOJ-IC        5V - Bi-Directional Octal Transceiver
2    74HCT166D    SOJ-IC        5V - SHIFT REGISTER

The IC's listed in the A4000 are generally those effected by battery leakage.

The LS174 is used for the clock circuit,
The F245 is part of the Fast RAM latching circuit
The 2x HCT166D are for both the mouse and joystick ports.

TH = Through-Hole components

hope the above helps.


interestingly I went through one of my 1B boards here, I have noticed that there is a subtle difference between the power ratings for the "10uf" - on the 1B board(s) here its 15v - where as on the Rev 1D.1 its 25v and on the 2B its 35v

[e5frog]

Isn't higher rated voltage "always" better and lower out of the question?

So using (for example) 35V caps for everything is not a bad thing as long as they fit properly.

The layout of the Rev 2B of the Amiga 600 is different, so it might be a good idea to check the markings on the board you have in case it's different. Changes in other components may have changed the required values.

My REV 1.5 has the same amount and values of it's "e-caps" as kipper2k's REV 1.3 board.

I added a picture here:
http://eab.abime.net/showpost.php?p=690733&postcount=14

[Zetr0]

@e5frog

Generally as a rule slightly high is better, but if you go too high the capcitor wont be able to work as efficiently.

Remeber that the capcitor is rated for xx at a given voltage - to much or too little will effect this rating.

i.e.

a 100uF Capacitor at 35v - should be happy in a circuit demanding half that. However a 100uF Capacitor at 100v in a 15volt circuit would be too much and the capacitance will be effected.

As a rule of thumb (and this is just a personal not a professional opinion) one shouldn't use no more than twice the rated voltage capacitor for the circuit.

There are exceptions to this rule with heavy high-voltage and inverse circuits

[e5frog]

So... if they already used twice the rated voltage to start with and I buy twice that - I'm on thin ice... ?

I got all the correct values for the A600 but I thought I should take care of my <start C64 rant> C64 as well, I was a little careless when desoldering ROM with a heat-gun (I usually cover what is not supposed to come loose with aluminum foil and make a hole for the part that needs to come off) so I damaged some e-caps and thought I'd better re-cap the whole thing anyway since they've been there since 1984... possibly '83. I'm hoping it will solve the problem with my TFC3 not working in that computer...

I noticed a few IC:s had already been swapped, the mobo is dated 1983 but one 6526 is dated '86 and some other circuits as well have later date codes. Not much stuff in sockets, only the SID (MOS 6581 2783, no revision) and two 74LS257 where the memory is. And now also the kernal - it's a factory fitted Swedish version so I tried swapping roms to see if the TFC3 would start with a standard kernal rom but it made no difference - so I installed a socket before putting it back. Perhaps swapping the PLA would have been a better attempt. Or it's just the timing with one or more circuits that's off, perhaps I should install sockets for everything and use it to test stuff - as I have it apart anyway.

<end C64 rant> ;-)

[Loedown]

If the cap was rated at 25V and you use 50V, in most cases that's cool, if you instead use a 100V rated part that's not cool.

I've had to upgrade the caps in HP1702 LCD screens from 16V to 25V, the 16V parts were running too close to the wind.

[e5frog]

So I put the whole motherboard in the dishwasher at 65 degrees centigrades and a plain tablet of washing up powder... I let it dry for a day and a half before I touched it again, this are the old caps at the power connector before the washing:



I had to protect the toroid at the power connector with some aluminum foil so the plastic wouldn't melt from the heat. The two caps between the audio outputs and the keyboard connector was also a bitch. Had to remove the moveable plastic part of the keyboard connector and mask the part left on the board + the audio connectors with aluminum foil as well to be able to get in there and solder without melting it...

I made a quick sketch - with a pencil, on a piece of paper - so I would know which values to put where. I had replaced the others up until then one or two at the time.

Here's the same area with the caps there removed, the leaking caps have made some damage here - no broken traces as far as I could see. I guess you can't be 100% sure unless you desolder all the circuits around there and take a look - I'll do that if it doesn't work after I'm finished.




I thought about how to solder the new ones so they wouldn't get in the way of each other, the hole mounted had to wait until last. Here's the finished result in that area:



I put a dot on each of the new caps so I wouldn't mix them up while working.

Here are the old ones:


Two of the hole mounted was a real pain to desolder, the pin in the ground area was really rough to get loose and then to clear the hole from solder to place the new cap there. The ground plane moves a lot of the needed heat from the solder area but I got it eventually, just need to heat until it loosened up.

This is not a project for a beginner, I have been soldering for 20+ years and apart from installing mod chips in PS2:s this is probably the hardest work I have done so far. I'm otherwise used to building prototypes and so with surface mounted components. Soldering new parts is usually a lot easier than soldering stuff off.

All the old caps was measured to their correct value - even the ones that definitely had leaked, so using the cap measure setting on the multimeter doesn't help trying to find faulty caps.

I also removed solder and resoldered some components that had oxidation because of the leakage, it was mostly just one of the joints of some of the small plain (not electrolytic) surface mounted caps and a few resistors.

Now everything works just fine - the A600 started up right away with no trouble at all - well almost - the disk drive didn't want to work at first, but after removing and reattaching the connector two times it started to work again - don't know if it was oxidation or if the ribbon cable wasn't attached right in the connector - these things should perhaps be soldered as well - to work better in the long run?

[rkauer]

That's why I have a 120W solder pistol: those ground planes are bitches!

[pandy71]

also this one (lower pices than Elfa i think)
http://www.tme.eu/en/