2205 panel lamp ribbon removal

[Gregory]

I'm doing an overhaul on the 2205 and must replace lamps on the front panel indicator PWB. How does one go about removing or unplugging the ribbon at the driver board end?




Also there seems to be issues with the speaker relay lugs being smaller (narrower and perhaps thinner) so the existing push-on terminals do not `grip´ the lug properly. They also tend to rotate sideways from the relay lug centerline. Should I buy the proper size and re-terminate each of the wires? What about parallel-soldering the wires in place?

The foam-backed tape that's used to space the front panel from the chassis has crumbled, and has been removed. What is a good replacement product?


TIA

-Gregory


Note: See "MC2205 Love" post in McIntosh forum for main project.

[dewickt]

The ribbon cable plugs into the small white connector on the circuit card, be gentile with the cable as the pins are easy to bend. Before changing the terminations at the relay I would try tightening the terminals, give each side a good squeeze and if it does not crack or break it will be nice and tight. There are good reasons to use push on connectors instead of soldering, the first is serviceability, convince in replacement, keeps soldering heat from damaging components, and last of all it makes it easier to build.

[Vintage Pete]

Originally Posted by dewickt

The ribbon cable plugs into the small white connector on the circuit card, be gentile with the cable as the pins are easy to bend. Before changing the terminations at the relay I would try tightening the terminals, give each side a good squeeze and if it does not crack or break it will be nice and tight. There are good reasons to use push on connectors instead of soldering, the first is serviceability, convince in replacement, keeps soldering heat from damaging components, and last of all it makes it easier to build.

Hey Terry,

Glad to see you chimed in...I've suggested in the other thread that Greg talk to you on this relay issue...


Pete

[Gregory]

Originally Posted by Vintage Pete

Hey Terry,

Glad to see you chimed in...I've suggested in the other thread that Greg talk to you on this relay issue...


Pete

Yeah.. Pete has already made some great suggestions. You sure I can pop out those eight meter lamps from the top? If so, then I'll make a pry-bar/wedge out of half a clothes pin and use that. Somewhere around here is a plastic screwdriver blade.

Now I'm running into trouble with the diodes. D120 is the crispy one on the Lamp board. I ordered 1N4004's but McIntosh says the cross references are:

 
Mc part#     Commercial        Schematic
 
070-031      1N5395GP      D120, D302, D303, D308
070-047      1N4148          D101 through D118

And also a 070-031 (D308) across speaker relay solenoid.


-Gregory

[Vintage Pete]

Greg,

I think I'd order any replacement parts (aside from lamps) from Mac, to be safe.

Yes, I am quite sure the meter lamps pop out from the top. See photo. (sorry the pic is a bit fuzzy but does show what the deal is). I was able to get it started with just my fingernals, then coaxed it the rest of the way with a small screwdriver. There is just one wire-it grounds by way of chassis.

Pete

[Gregory]

Originally Posted by dewickt

The ribbon cable plugs into the small white connector on the circuit card, be gentile with the cable as the pins are easy to bend. Before changing the terminations at the relay I would try tightening the terminals, give each side a good squeeze and if it does not crack or break it will be nice and tight. There are good reasons to use push on connectors instead of soldering, the first is serviceability, convince in replacement, keeps soldering heat from damaging components, and last of all it makes it easier to build.

Thanks Terry.. I just hate to apply force to something that I don't know comes apart or not. Those relay terminals still aren't attached to my satisfaction, and I may replace diode D308 which is across the lower relay lugs.

General question: when do you apply the rule "ain't broke, don't fix it" when it comes to a 2205 amplifier?

-Gregory

[Gregory]

Originally Posted by Vintage Pete

Greg,

I think I'd order any replacement parts (aside from lamps) from Mac, to be safe.

Yes, I am quite sure the meter lamps pop out from the top. See photo. I was able to get it started with just my fingernails, then coaxed it the rest of the way with a small screwdriver. There is just one wire-it grounds by way of chassis.

Pete

Thanks Pete.. McIntosh says part 070-031 is a #1N5395-GP commercial diode and Mouser has these: 1N5395 diode

McIntosh Parts want $5 each for the -031 diodes, so Mouser would be a good source. I purchased a replacement fuse holder for the MR77 from Mc Parts for $20 and was surprised how lite it was. We had fuse holders in the stock room at work that were heavier-built than what I received. Ironically I've misplaced that fuse holder.

As for the lamps, the whole compliment of exact replacement lamps for the 2205 was purchased for just over $30 with 50% extra (whole packs) and I don't recall how much Mc charges for each bulb. Back to your reply about the 1866 meter lamps, they came out with just moderate force, and there were no significant marks left in the housing afterward.

-Gregory

[Vintage Pete]

Originally Posted by Gregory

Thanks Pete.. McIntosh says part 070-031 is a #1N5395-GP commercial diode and Mouser has these: 1N5395 diode

McIntosh Parts want $5 each for the -031 diodes, so Mouser would be a good source. I purchased a replacement fuse holder for the MR77 from Mc Parts for $20 and was surprised how lite it was. We had fuse holders in the stock room at work that were heavier-built than what I received. Ironically I've misplaced that fuse holder.

As for the lamps, the whole compliment of exact replacement lamps for the 2205 was purchased for just over $30 with 50% extra (whole packs) and I don't recall how much Mc charges for each bulb. Back to your reply about the 1866 meter lamps, they came out with just moderate force, and there were no significant marks left in the housing afterward.

-Gregory

Gregory,

Sounds like you're moving along very nicely.... I was pretty sure you'd have no trouble with those lamps.

Pete