• Hello, Guest! Welcome back, and be sure to check out this post for more info about the recent service interruption and migration.

The caseless Quadra 840AV gets a case

SophieRose

Active member
I came across a Quadra 840AV board recently and after a recap n reflow it came alive..
I decided to case it in a spare tatty IIci case and it fits really well after I cutout some of the port holes at the rear, even the nubus slots line up as do some of the plastic locators the board slides onto and the screw that holds the plastic drive shell.
Well chuffed.:)

Voila.
smallquad.jpg
smallquad2.jpg

Next stage.. is to fit an upright psu socket and some sort of atx adapter and a small psu.
 

Byrd

Well-known member
The best thing is you've bypassed the worst things about an 840AV: the hard to access case, the cheap brittle plastic and rust (every 8x0 case I've come across has rust on the RF shielding - not patina!).
 

Trash80toHP_Mini

NIGHT STALKER
Looks like a great setup! Nice to know 840 boards fit in these cases too!
Ayup, but as she said you've gotta mangle some of the backplane. Now I'm wondering if it's a drop in replacement for a Quadra 700 case but for the access plate for that third NuBus/PDS slot?
 

tnova

Member
I came across a Quadra 840AV board recently and after a recap n reflow it came alive..
I decided to case it in a spare tatty IIci case and it fits really well after I cutout some of the port holes at the rear, even the nubus slots line up as do some of the plastic locators the board slides onto and the screw that holds the plastic drive shell.
Well chuffed.:)

Voila.
View attachment 40057
View attachment 40058

Next stage.. is to fit an upright psu socket and some sort of atx adapter and a small psu.
Nice work. What steps did you take for the reflow you mentioned? I’ve got a 840av board I’m trying to revive - completed recap but no chime or video when PSU switches on. I’m wondering if a PSU pssue possibly.
 

ktkm

Well-known member
Cool! Please let us know when you have solved the PSU positioning. I have a spare IIci case that would love to house a Quadra 840AV!
 

beachycove

Well-known member
I once tried a G4 AGP Graphics logic board in a IIci case, just for fit, and thought it could be made to work. Didn’t take it any further.
 

Paulie

Well-known member
Is the PSU connector in the same place as the Q650/800 boards? I've got a Q650 in my Q700 case and the PSU slots directly into the same place it would with the Q700 board.
 

joshc

Well-known member
No, the PSU concetor is not in the same place and it's a right angle connector so a mod will have to be done to fit a PSU in there.
 

Byrd

Well-known member
Nice work. What steps did you take for the reflow you mentioned? I’ve got a 840av board I’m trying to revive - completed recap but no chime or video when PSU switches on. I’m wondering if a PSU pssue possibly.

It's all those fine fragile custom ICs around the caps (most are additional DSPs for the 840 "AV" moniker) that can be taken out very easily from cap goo - usually requiring a very deep clean (even ultrasonic cleaner) and examination under a magnifier to inspect.
 

SophieRose

Active member
It's all those fine fragile custom ICs around the caps (most are additional DSPs for the 840 "AV" moniker) that can be taken out very easily from cap goo - usually requiring a very deep clean (even ultrasonic cleaner) and examination under a magnifier to inspect.
Exactly this, A couple of the VLSI ICs had legs that had become disconnected due to cap goo and needed resoldering after a darn good clean.
 

tnova

Member
It's all those fine fragile custom ICs around the caps (most are additional DSPs for the 840 "AV" moniker) that can be taken out very easily from cap goo - usually requiring a very deep clean (even ultrasonic cleaner) and examination under a magnifier to inspect.
Thanks I had put my 840av board in a heated ultrasonic 50°c with light alkaline cleaner (Elma Tec A1) and dried with IPA … still no chime. Looked over the board carefully and spot tested traces with a meter. Next step will be poking the VLSI ASIC legs under a lens to see if any loose. Some of these look specific to NuBus and sound subsystem so maybe ancillary so will maybe look at the bomarc drawing to see which order to go in. I am afraid to lift the chips given the fine legs and not having a proper SMD hot air station attachment or technique for resoldering.
 

tnova

Member
Exactly this, A couple of the VLSI ICs had legs that had become disconnected due to cap goo and needed resoldering after a darn good clean.
any tips on resoldering or advice on these is appreciated. I struggle with even getting the PLCCs which have a lot wider leg spacing. Also any specific things to check continuity wise like common ground points with a meter on this board is appreciated
 
Top