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About to order some caps for first recapping of many (Mac Plus)

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2019-05-27_1642

 

I'm using this list as my reference from jagshouse.com, through the wayback machine at this link (at the bottom of the page): https://web.archive.org/web/20170211044838/http://www.jagshouse.com/68kfaq.html

 

I have 2 Mac Pluses and I'll eventually work on both (plus a few number of other compact macs, such as a Mac SE, Mac SE/30, Classic I, Powerbook 170 and one HyperDrive FX/20). I live in Canada so they are not the International version, but the US voltage.

 

This first Mac Plus boots to a sad mac error 01E000 (a search told me ROM chip error)

 

Steps I've done:

-Opened the case

-Tried reseating both Hi and Low ROM chips, gently sanded the pins, reseated it - to no avail. I still get the same sad Mac. I didn't see any sign of corrosion on these chips

-Discharged the CRT with a 20 MOhm resistor smoothly

-Taken out the analog and logic board to prep for recapping

-Made sure I got access to good soldering equipment and a colleague tech on hand who can make sure I'm not making gross mistakes with desoldering/soldering

 

Steps I'm not sure about:
-I think I can see some corrosion under the analog board, but nothing that runs wild all over the place. It's mostly located nearby specific solder points

-How much of that list at the top of my post must be followed to the letter. Must I replace all of these (including resistors)? The prices on digikey have changed quite a bit and it seems like it's gonna take a while to decide specific parts. Does anyone have a decently recent (ie last 10 years) shopping list from DigiKey for this machine (again, non-International)

 

 

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It might be hard to find radio shack stores any more.  When part numbers are referenced in your post? Are they part numbers supplied by a vendor or a part numbers from a specific manufacture?
 
I  have found that the huge mail order electronics supply house called Mouser had all the capacitors (and other parts) that I needed for my color classic rebuild.  Mouser will let you buy just one part or a thousand.  I find that shipping is reasonable as well.
 
Here is a link to the main web site:
 
 
And here is a link to just the capacitors that they carry:
 
 
Other folks here can tell you which kind of caps you can buy (buy the best that will last a lifetime, or modern axial capacitors that will probably last another 40 or 50 years, etc, you decide).
 
The other two large electronics vendors are:
 
 
and
 
 
I find that Mouser usually has what I need, the price is right, and I do not get ripped off for postage.
 
Also note that some folks on this forum can sell you a packet of parts just for your machine.  It can save you a lot of time (but cost a little more).
 
have fun....
 
mraroid
 
 
 
 
 
 

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I am pretty sure the reason of the sad mac is faulty rom chips. Cleaning and reseating them wont do, after 30 years those chips detoriate even they dont show any sign of corrosion. All you need to do is burn replacement roms on couple of 27c512 eproms. PM me if you need them.

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I can't seem to be able to find a C1 on either mouser or digikey.

 

Assuming:

Electrolytic, Aluminium Can

Bi-Polar (that's their keyword for non-polar)

Here's a search on Digikey:

https://www.digikey.ca/products/en/capacitors/aluminum-electrolytic-capacitors/58?FV=402e23%2Cd0000f%2Cmu2.2µF|2049%2Cmu3.3µF|2049%2Cmu4.7µF|2049%2Cmu6.8µF|2049%2Cffe0003a&quantity=0&ColumnSort=2049&page=1&stock=1&pageSize=500

 

as you can see, there's nothing at 3.9 uF. It skips from 3.3 uF to 4.7 uF

 

Can I use a 4.7 uF instead?

 

Could be, since I'm reading this line from the Mac Classic Repair Notes p.4 ("the value is not terribly critical....")

 

2019-05-28_1620

 

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Thanks for all the suggestions. I'll admit I jumped the gun and ordered some analog parts for the most critical caps first for my 2 mac Plus and went with this (even got spares for a 3rd machine), all on DigiKey. I did look on Mouser first but I wasn't feeling the shipping price to me. I might not have optimized the ratings vs price point everywhere but I have to start somewhere. There are a few more caps for the analog board that could be replaced, and I have to start listing what I need for the logic board (but both Mac Plus logic boards look pristine so far). I will for sure compare prices with your sheet @superjer2000 for my next order

 

2019-05-30_1308

 

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Finally got underway and started on these 4 first ones with a tech help on hand for my questions and small demo.

C9 isn't listed in the Larry Pina texts of old, but it seemed to exhibit the beginnings of bulging on my board.

 

Which leads to the question: do you really relentlessly replace everything with a CXX and CRXX eventually or can you avoid some of them? This will get pricy for multiple machines if I really replace 'em all.

 

Here's a pic of my first 4 newly installed caps.

 

2019-05-30_1431

 

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When I recap a pre-SE board, I always replace EVERYTHING on my list - That list includes all electrolytic capacitors plus all of the upgrades in the repair/upgrade secrets book plus a couple of other identified failure points.  While I can't say for sure, I think the total cost of the parts I bought was probably like $200 which was enough for 10 boards.  After doing this a few times, I haven't had any issues with any of my recapped boards (of course, they all probably have less than 20 hours on each of them so with any luck they'll outlive me).

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I made some progress today. Replaced some more caps. Still got more to do, but I have to order them.

This Mac Plus #2 had bad ROM chips, which I confirmed by swapping in the ones from my working childhood Mac Plus #1.

I tested a boot and so far, so good - making it the first working test after I've done extensive desolder/solder work.

 

 

64298288_10156215575447805_8809110187613880320_n.jpg

62255050_10156215575267805_1626253168646029312_n.jpg

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