Fostex R8 R/P Cards

A

avieth

New member
In my quest to align my R8, I have come to an issue. I've set the REC CAL level on each card to the proper level, and now it's time to adjust the METER CAL parameter so that all the meters read 0 when a -10dBV signal is encountered. For some reason the Fostex engineers put the METER CAL knob on the connector board, so that it is covered by the 8 R/P cards that conveniently have their controls face up.

Since the meters do in fact need tweaking, I'll have to take the cards out to access the METER CAL knobs. I've tried pulling the cards but they don't come out. How do I get them out?
 
I don't know if they're even designed to come out :o The service manual and user manual say nothing about removing them.
 
Studying the PCB layout for the Connector Board and the amp cards, there are multipin connectors on the Connector Board where the amp cards connect...I don't want to tell you to yard on 'em and end up breaking something, so that is not what I'm telling you to do, but I believe the cards are removeable and may take some working. You may want to try and get some DeoxIT down into those connectors...I realize the space is cramped, but if you lay the deck on its back and have some way to get an extra-long tube on the can of DeoxIT, with some good light you may be able to apply a light amount to the back-side of the connectors on the amp cards, let it sit for a minute or two and then try to remove the cards again. Start with just one of them maybe...but what's the deal with the little PCB's ("Fostex 836 102") at the bottom back of the amp cards (look at page 36 of the Service Manual...the PCB layout for the amp card)? Are those attached to the amp card? That would make it hard to slide those things out...;) I don't see those on the exploded views (the little PCB's), so I'm guessing they are not attached to the amp card PCB's, but just to be sure I thought I'd bring it up.

I can see that it is pretty crowded between cards to get to those trimmers for the x-talk and meter calibration, but do you have a long-shaft tweaker? I have a ceramic tweaker that I got at my local electronics parts shop. The shaft is about 11" long and something like that might allow you to get back in there without removing the cards.
 
sweetbeats said:
Studying the PCB layout for the Connector Board and the amp cards, there are multipin connectors on the Connector Board where the amp cards connect...I don't want to tell you to yard on 'em and end up breaking something, so that is not what I'm telling you to do, but I believe the cards are removeable and may take some working. You may want to try and get some DeoxIT down into those connectors...I realize the space is cramped, but if you lay the deck on its back and have some way to get an extra-long tube on the can of DeoxIT, with some good light you may be able to apply a light amount to the back-side of the connectors on the amp cards, let it sit for a minute or two and then try to remove the cards again. Start with just one of them maybe...but what's the deal with the little PCB's ("Fostex 836 102") at the bottom back of the amp cards (look at page 36 of the Service Manual...the PCB layout for the amp card)? Are those attached to the amp card? That would make it hard to slide those things out...;) I don't see those on the exploded views (the little PCB's), so I'm guessing they are not attached to the amp card PCB's, but just to be sure I thought I'd bring it up.
Click to expand...

I don't know what those (FOSTEX 836 102) are, but they definitely are not attached to the R/P cards on my unit.

So you think the connectors just need some lubrication... I think I have contact cleaner somewhere in my house, I'll give it a shot once I find it. Thanks for the tip.

I can see that it is pretty crowded between cards to get to those trimmers for the x-talk and meter calibration, but do you have a long-shaft tweaker? I have a ceramic tweaker that I got at my local electronics parts shop. The shaft is about 11" long and something like that might allow you to get back in there without removing the cards.
Click to expand...

I hate to admit it, but I ended up using a metal flathead screwdriver to adjust the meter cal controls. I managed to do it without shorting anything out or snapping any components off. I do have a long, plastic tool that was included with my digital multimeter, but it's too thick.

The screwdriver won't work for the crosstalk controls though. For that I'll definitely need to remove the cards.
 
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