Hello! Since 1981 I have owned a SAE 2400L Amplifier. Unfortunately, the amp was completely submerged in a flooded basement recently. The that shop that inspected the unit tells me that several of the internal components should be replaced from a donor unit(s).
Does anyone out there know of a parts source, or a donor 2400L that could help bring my unit back to life? One of the first components needed is the primary power transformer. Mine is one of the older "square" ones (not an newer toroidal).
Any help or insights would be appreciated. Thanks in advance.
Does anyone out there know of a parts source, or a donor 2400L that could help bring my unit back to life? One of the first components needed is the primary power transformer. Mine is one of the older "square" ones (not an newer toroidal).
Any help or insights would be appreciated. Thanks in advance.
Vendetta, thanks for the doc! Much appreciated!!
Still looking for parts and currently exploring placse that may be able to rewind the primary transformer, as a start.
Did the amp work before the flood?
Did the repair shop have power applied or was this just a visual inspection/assessment/recommendation?
Is the unit thoroughly dried-out? Once it is, apply power gradually with a Variac or a light-bulb power limiter. You might be pleasantly surprised.
Good luck!
Did the repair shop have power applied or was this just a visual inspection/assessment/recommendation?
Is the unit thoroughly dried-out? Once it is, apply power gradually with a Variac or a light-bulb power limiter. You might be pleasantly surprised.
Good luck!
Most of it is probably ok. Suspect parts would be switches and jacks (which can be cleaned), and trim pots and small electro’s (which I would just replace before starting). Everything else would be sealed well enough not to suffer damage.
Yes! The amp worked before the flood. I do not believe the shop applied power to the unit as they were concerned about the primary transformer having been submerged for a couple of days, and there was evidence of board lamination degrading on the driver boards, The sockets for the 8 output transistors were also an area of concern.
I took the unit all apart before taking to the shop (the chassis was a single part on its own). At that time, I replaced the 4-way bridge rectifier as one of the leads corroded right off after the flood. I replaced and upgraded the original main filter capacitors, and replaced the primary fuse (10 amp) receptacle because of corrosion. Additionally I cleaned and applied ACF-50 anti-corrosion spray to all the boards. I could not the get the covers off the 48V protection relays to clean and spray, however. There IS evidence of a couple of discrete components on the driver boards (both resistor, I believe) with physical corrosion to where one of the connections is corroded right off.
I would think the unit is thoroughly dried out. The only reservation is the primary transformer, as I did not disassemble that component. Other than that everything is bone dry.
I am a hesitant to apply power based on what I was told. I have considered removing the primary transformer and testing it as a standalone unit. Some help in checking that unit out may be requested. Another option would be to find a shop that could inspect the transformer. Any leads on such a transformer shop would be appreciated.
I hope I have answered your questions and provided some additional background information. Feel free to ask any other relative and I will answer as best I can. I appreciate your interest in this!! Thank you!! Cheers!
Disconnect the power trafo secondary, and run the primary thru a dim bulb. Let it idle for a couple of DAYS. If it doesn't short out and light the bulb, it’s probably fine.
The most conservative path would probably disconnect the Red and Gray leads at +/- 60V rails and raise applied AC with Variac/ light-bulb power limiter. Assuming no sizzles and and there's encouraging 60V supplies, then restore connections (one channel at a time, if convenient) and repeat the gradual, watchful power up.
I'm optimistic for you. Good luck.
I'm optimistic for you. Good luck.
It takes days to dry-out a keyboard after dishwashing. A large transformer may be much longer. I'd want to put it on a heating duct register or a water/steam heat radiator, for a week at least.
Folks, thanks for the replies and the guidance! The amp has been drying out since early August, exposed to ambient temp and hunidity since then. I would like to think it is sufficiently dried out.
As far as powering up, I may be asking for some details on the needed steps. I don't have a Variac but would be willing to pick one up. I figure the unit is not serving much purpose right now. One thought would be to replace the few known corroded components on the driver boards before applying power. Or would this be a bad move?
I have to be out of town the next few days, but willing to poke at this thing upon my return. I appreciate the interest and the willingness to help out. We can make this a community project. Worst case, I keep the fire extinguisher handy!! Many thanks!!
A variac certainly makes life easier. If you can‘t/won’t obtain one, you must use a dim bulb. I usually use both together.
Transformers can trap a little moisture, even after a couple months. You should see how long it takes to air dry multiple varnish dips - that will enlighten you. Plugging it in and letting the core self-heat with just a few watts will do in 2 days what 2 months of sitting won’t. The fact that the trafo is just a few degrees higher than the surroundings accelerates the process. The moisture itself won’t really hurt anything, but if the insulation on the wire has degraded it could short. It might not short till there is mechanical stress on it from the magnetization curve. Having it run on a dim bulb for a while lets you do both at the same time, and it can run unattended without risk of fire.
If I’ve got an old (even new old) trafo that’s been sitting up in the attic of the shop for months/years I’ll let it run like that before I try to use it.
Parts with obvious corrosion should be replaced. Many times they will continue to corrode once it’s started. It may look clean after you’ve scraped it off, but come back in a month the leads might be green again. I’ve had transistor leads corrode completely through. And if it starts to compromise the epoxy-to-metal seal on a plastic power transistor, it will go bad eventually. Maybe not this year or next, but eventually you’ll be back in there replacing it and all the collateral damage. Corrosion could start up later, so keep an eye on things. If a shop didn’t want to mess with it after the flood, this might be what they’re afraid of. At typical “shop rates” it can be a lot of money - more than most would be willing to pay - or perhaps repeated warranty work. For DIY it’s do-able.
Transformers can trap a little moisture, even after a couple months. You should see how long it takes to air dry multiple varnish dips - that will enlighten you. Plugging it in and letting the core self-heat with just a few watts will do in 2 days what 2 months of sitting won’t. The fact that the trafo is just a few degrees higher than the surroundings accelerates the process. The moisture itself won’t really hurt anything, but if the insulation on the wire has degraded it could short. It might not short till there is mechanical stress on it from the magnetization curve. Having it run on a dim bulb for a while lets you do both at the same time, and it can run unattended without risk of fire.
If I’ve got an old (even new old) trafo that’s been sitting up in the attic of the shop for months/years I’ll let it run like that before I try to use it.
Parts with obvious corrosion should be replaced. Many times they will continue to corrode once it’s started. It may look clean after you’ve scraped it off, but come back in a month the leads might be green again. I’ve had transistor leads corrode completely through. And if it starts to compromise the epoxy-to-metal seal on a plastic power transistor, it will go bad eventually. Maybe not this year or next, but eventually you’ll be back in there replacing it and all the collateral damage. Corrosion could start up later, so keep an eye on things. If a shop didn’t want to mess with it after the flood, this might be what they’re afraid of. At typical “shop rates” it can be a lot of money - more than most would be willing to pay - or perhaps repeated warranty work. For DIY it’s do-able.
Back from a short vacation...
The shop was concerned about long term corrosion. However, I must say that after a few months since cleaning and spraying components down with ACF-50, there does not appear to be worsening corrosion.. At least for now.
Earlier today, I built and tested a dim bulb tester. I am in the process of purchasing a Variac. Once that arrives, to what degree should I attempt to power the 2400 up? I was thinking about disconnecting/isolating the driver boards and the LED meters.
In an earlier post it was mentioned to disconnect the Red and Gray leads at +/- 60V rails. There appears to be three sets of Red and Grey leads coming from the area of the 2 main filter caps. One set goes to the front panel power switch, the others appear to go down to the main transistor board. I do have pics of this area of the amp, if needed.
Initially, I would want to isolate the main transformer as much as possible before applying any AC power to the amplifier. Is this too conservative?
Thanks in advance for any help.
The shop was concerned about long term corrosion. However, I must say that after a few months since cleaning and spraying components down with ACF-50, there does not appear to be worsening corrosion.. At least for now.
Earlier today, I built and tested a dim bulb tester. I am in the process of purchasing a Variac. Once that arrives, to what degree should I attempt to power the 2400 up? I was thinking about disconnecting/isolating the driver boards and the LED meters.
In an earlier post it was mentioned to disconnect the Red and Gray leads at +/- 60V rails. There appears to be three sets of Red and Grey leads coming from the area of the 2 main filter caps. One set goes to the front panel power switch, the others appear to go down to the main transistor board. I do have pics of this area of the amp, if needed.
Initially, I would want to isolate the main transformer as much as possible before applying any AC power to the amplifier. Is this too conservative?
Thanks in advance for any help.